BIND 9.11.0 Configuration Options
BIND configuration options as of BIND 9.11.0 are listed below and each option's applicability to the name server configuration (named.conf - options column) view statements or zone statements by zone type. This is intended as a quick reference listing each option in alphabetical order by option name. Option support varies by BIND release so check the options file within the doc/misc directory of your BIND installation to compare those supported in your release with this table.
The following conventions are used in the table:
- A value of yes in the table indicates that the option specified in the corresponding row is supported within the statement block identified by the corresponding column for BIND 9.9. A blank value means it does not. A value of 'N/A' means that the option may be specified but is either ignored or not implemented as discussed in the corresponding description column for the table entry. Text in narrow font indicates that a value of the type so indicated must be specified. The table includes the following:
- address_match_list - a name corresponding to a defined address match list within the configuration file
- algorithm - one of a pre-defined set of valid hash algorithms
- bytes - an integer quantity indicating a number of bytes
- domain - a domain-formatted text string e.g. www.ipamworldwide.com.
- IP_address - an IPv4 or IPv6 formatted address value
- ip_dscp - the value of the IP header differentiated services code point (DSCP) field for OSs that support DSCP.
- minutes - an integer value indicating the number of minutes
- number - an integer quantity
- pathname - a text string indicating a directory path on the server
- port - an integer indicating a UDP or TCP port number
- port_list - a list of integer port numbers
- size - a size measure expressed as an integer and unit e.g. 10g for 10 gigabytes; if no unit is provided the default is bytes
- string - a text string
- zone_name - the name of a zone in domain format
- Keywords are parameters though non-italicized. Examples are yes no first ignore.
- ( a | b | c ) - parentheses denote a number of parameters one of which can be selected; the pipe character represents 'or.' Thus this expression indicates that a value of either a b or c can be specified.
| Option name and syntax | Option description | options | view | zone master | zone slave | zone static-stub | zone forward | zone hint | zone redirect | |
|---|---|---|---|---|---|---|---|---|---|---|
| acache-cleaning-interval minutes; | Defines the interval at which the server will analyze the additional section cache (acache) to remove records with expired TTLs. The default is 60 [minutes]. Setting this option to 0 disables acache cleaning. | yes | yes | |||||||
| acache-enable (yes | no); | "Enables the additional section cache (acache) which is an internal BIND caching mechanism that provides a ""shortcut"" to the additional section content of each answer resource record. Enabling acache can improve query performance especially for authoritative zones each with several delegations and many glue records (which are placed in the additional section of a query response). Disabling acache can reduce the risk of cache poisoning." | yes | yes | |||||||
| additional-from-auth (yes | no); | When set to yes this option specifies that the server will add records to the additional data section of its response to a query from a resolver or another server. The additional section records would include any authoritative information related to the query e.g. A records for an MX query or CNAME and DNAME referenced records in other zones for which the server is authoritative. The default is yes. | yes | yes | |||||||
| additional-from-cache (yes | no); | When set to yes this option specifies that the server will add records to the additional data section of its query response any cached information related to the query e.g. CNAME and DNAME referenced records for which the server has cached data. When set to no this option disables the use of cache not only for additional data but for query answers as well. The default is yes. | yes | yes | |||||||
| allow-new-zones { yes | no }; | Configures whether zones can be added to the server at runtime using rndc addzone or deleted using rndc delzone. The default is no. | yes | ||||||||
| allow-notify { address_match_list }; | Accept Notify messages from hosts identified by the address match list in addition to corresponding zone masters. The default is to allow Notify messages from the configured zone master server(s) as configured in the masters statement of a given zone declaration. | yes | yes | yes | ||||||
| allow-query { address_match_list }; | Defines an ACL regarding who can query this server based on the address match list definition. The default is any. | yes | yes | yes | yes | yes | yes | yes | ||
| allow-query-cache { address_match_list }; | Specifies which hosts based on the address match list may receive query answers from the server's cache. If not specified this option defaults to the address match list specified in the allow-recursion option; if this is not set then that set in the allow-query option is used; otherwise this option defaults to {localnets; localhosts;}. | yes | yes | |||||||
| allow-query-cache-on { address_match_list }; | Specifies on which name server interface(s) queries will be accepted that may receive answers from the server's cache. For example this option could be configured to allow cache queries on the interface(s) facing the internal network. | yes | yes | |||||||
| allow-query-on { address_match_list }; | Specifies on which name server interface(s) queries will be accepted. For example this option could be configured to allow queries on the interface(s) facing the internal network. | yes | yes | yes | yes | yes | yes | |||
| allow-recursion { address_match_list }; | Defines an ACL on who can issue recursive queries to this server based on the address match list definition. If not specified this option defaults to the address match list specified in the allow-query-cache option; if this is not set then that set in the allow-query option is used; otherwise this option defaults to {localnets; localhosts;}. | yes | yes | |||||||
| allow-recursion-on { address_match_list }; | Specifies on which name server interface(s) recursive queries will be accepted. For example this option could be configured to allow recursive queries on the interface(s) facing the internal network. The default is to accept recursive queries on all server interfaces. | yes | yes | |||||||
| allow-transfer { address_match_list }; | Specifies an ACL on who can receive a zone transfer from this server. The default is any. | yes | yes | yes | yes | |||||
| allow-update { address_match_list }; | Defines an ACL on who can perform a dynamic DNS update based on the address match list definition. The default is none. If the more granular update-policy option is specified within options view or zone blocks allow-update must not also be specified within the corresponding statement block. | yes | yes | yes | ||||||
| allow-update-forwarding { address_match_list }; | Specifies an ACL defining from whom dynamic updates will be accepted for slave zones which will in turn be forwarded to the zone's master server. The default is none. ISC recommends using either any or none the default. This pushes the enforcement of update acceptance from this slave server to the master server. | yes | yes | yes | ||||||
| allow-v6-synthesis { address_match_list }; | BIND ignores this option; it was devised to provide a transition from AAAA to A6 records which are now deprecated. | yes | yes | |||||||
| also-notify { IP_address [port port ] [dscp ip_dscp] [key keyname] ; [IP_address [port port] [dscp ip_dscp] [key keyname] ; }; | Defines a set of IP addresses with or without corresponding port numbers to which to send Notify messages when a zone is updated (default = empty i.e. none). This option specifies additional Notify recipients to those specified in the zone's NS records. | yes | yes | yes | yes | |||||
| alt-transfer-source (IPv4_address | *) [port port] [dscp ip_dscp]; | Specifies an alternate transfer source IPv4 address and optionally port for performing inbound zone transfers or for issuing SOA queries or forwarded dynamic updates if the transaction failed with transfer-source parameters. Note that the use-alt-transfer-source yes option must be set. | yes | yes | yes | yes | |||||
| alt-transfer-source-v6 (IPv6_address | *) [port port ] [dscp ip_dscp]; | Specifies an alternate transfer source IPv6 address and optionally port for performing inbound zone transfers or for issuing SOA queries or forwarded dynamic updates if the transaction failed with transfer-source-v6 parameters. Note that the use-alt-transfer-source yes option must be set. | yes | yes | yes | yes | |||||
| attach-cache cache-name; | By default each view has its own cache database; this option enables sharing of a common cache database across some or all views. When set in the options directive all views will use the cache-name cache. Particular views may use their own cache by specifying a different cache-name within the view statement block. Cache sharing among views requires each view to support common cache-impacting parameters: check-names cleaning-interval dnssec-accept-expired dnssec-validation max-cache-ttl max-ncache-ttl max-cache-size and zero-no-soa-ttl. | yes | yes | |||||||
| auth-nxdomain (yes | no); | Allows the server to always claim that a negative answer from its cache is actually authoritative even if it isn't; the default is no do not always claim authoritative answers. | yes | yes | |||||||
| auto-dnssec (allow | maintain | create | off); | This option defines the degree of automation for BIND's automated DNSSEC key and signature management features.
| yes | yes | |||||||
| automatic-interface-scan { yes | no }; | Configures named to recan network interfaces on the server when interface addresses are added or removed. The default is yes. | yes | ||||||||
| avoid-v4-udp-ports { port_list }; | Specifies which port numbers to avoid as system-assigned source UDP ports over IPv4 typically to avoid firewall-blocked port numbers | yes | ||||||||
| avoid-v6-udp-ports { port_list }; | Specifies which port numbers to avoid as system-assigned source UDP ports over IPv6 typically to avoid firewall-blocked port numbers | yes | ||||||||
| bindkeys-file pathname; | Specifies the pathname on the server for the trusted keys for use in DNSSEC Lookaside Validation. The default is /etc/bind.keys. | yes | ||||||||
| blackhole { address_match_list }; | Defines an ACL defined by the address match list from which this server will not accept queries nor use to resolve a query. The default is none. | yes | ||||||||
| cache-file pathname; | Specifies the pathname on the server for the cache file but is used only for testing and should not be used. | yes | yes | |||||||
| catalog-zones { specifications }; | This option defines a catalog zone to facilitate zone updates for slave servers. Please refer to the catalog zones section for specification details. | yes | yes | |||||||
| check-dup-records (fail | warn | ignore); | Configures the server to check its master zones for resource records that are treated differently by DNSSEC but are semantically equal in plain DNS. The default is warn. | yes | yes | yes | ||||||
| check-integrity (yes | no); | When set to yes configures the server to perform zone integrity checks after loading of master zones; the integrity check consists of assuring MX and SRV records refer to hosts which have corresponding A or AAAA records (intra-zone checks only) and that glue records exist for delegated zones. The default is yes. | yes | yes | yes | ||||||
| check-mx (warn | fail | ignore); | Performs checking on MX records and will fail warn (default) or ignore based on whether the RDATA contains an IP address. | yes | yes | yes | ||||||
| check-mx-cname (warn | fail | ignore); | Configures the server to verify that MX records do not refer to CNAME records; applies when check-integrity yes is configured. The default is warn. | yes | yes | |||||||
| check-names (master | slave | response) (warn | fail | ignore); | Configures the server to validate owner names of A AAAA and MX records as well as RDATA names in NS SOA and MX records and also PTR records resolved based on queries for owners within ip6.arpa or in-addr.arpa zones. When defined within the options or view statement but not within zone declarations checking can be focused to master zones (default = fail) slave zones (default = warn) or responses received from other servers (response default = ignore). | yes | yes | yes | yes | yes | yes | |||
| check-sibling (yes | no); | Configures the server to verify that glue records exist for sibling zones i.e. other zones delegated by this server (as a common parent). For example the Rdata field of an NS record for a delegated zone may refer to a name server in a sibling zone: a.ipamworldwide.com. IN NS ns.b.ipamworldwide.com In such a case setting this option to yes causes the server to verify that a glue (A/AAAA) record exists for ns.b.ipamworldwide.com. This option only applies when check-integrity yes is configured. The default value is yes. | yes | yes | |||||||
| check-spf (warn | ignore); | If check-integrity is set this option dictates whether to check for the presence of a TXT record if an SPF record is found. Sender Policy Framework (SPF) RRTypes have been deprecated given the embedded deployments of SPF using the TXT record instead. The default value is warn. | yes | yes | |||||||
| check-sibling (yes | no); | Configures the server to verify that glue records exist for sibling zones i.e. other zones delegated by this server (as a common parent). For example the Rdata field of an NS record for a delegated zone may refer to a name server in a sibling zone: a.ipamworldwide.com. IN NS ns.b.ipamworldwide.com In such a case setting this option to yes causes the server to verify that a glue (A/AAAA) record exists for ns.b.ipamworldwide.com. This option only applies when check-integrity yes is configured. The default value is yes. | yes | yes | |||||||
| check-srv-cname (warn | fail | ignore); | Configures the server to verify that SRV records do not refer to CNAME records; applies when check-integrity yes is configured. The default is warn. | yes | yes | |||||||
| check-wildcard (yes | no); | Instructs the server to issue a warning upon detecting a non-fully resolvable wildcard (*) in its master zones if set to yes. The default is yes. | yes | yes | yes | ||||||
| cleaning-interval minutes; | Defines the interval at which the server will analyze the cache to remove records with expired TTLs (default = 60 [minutes]). | yes | yes | |||||||
| clients-per-query number; | Defines the minimum initial number of simultaneous outstanding recursive queries for a given name (i.e. of the same qname qtype qclass). In this context the server issuing such queries is the ""client"" referred to by the option name. (default = 10) | yes | yes | |||||||
| cookie-algorithm (aes | sha1 | sha256); | Defines the algorithm to be used when generating the server cookie, which serves as a lightweight DNS message authentication mechanism. The default is aes if supported by the server, otherwise sha256. | yes | ||||||||
| cookie-secret secret_string; | Specifies the shared secret used for generating and verifying EDNS COOKIE options within an anycast cluster. The shared secret is encoded as a hex string and needs to be 128 bits for AES128, 160 bits for SHA1 and 256 bits for SHA256. If not set, the system will generate a random secret at startup. | yes | ||||||||
| coresize size; | Defines the maximum size of a core dump file. The default is default which is the default core dump file size permitted by the operating system. | yes | ||||||||
| database string; | Specifies the type of database used for storing zone data. The string argument is interpreted as a whitespace-delimited string with the first entry comprising the database drivers linked into the server and the remaining entries passed to the database as arguments. The default type is rbt BIND 9's in-memory red-black-tree database (which does not take additional arguments) | yes | yes | yes | yes | |||||
| datasize size; | Defines the maximum size of memory the server may use. The default is default which is the amount of memory allocated by the operating system by default though this option is useful when specifying a size greater than the operating system default if this amount is too small. | yes | ||||||||
| deallocate-on-exit (yes | no); | BIND 8 provided this option to enable deallocation of memory upon exit to check for memory leaks; BIND 9 always performs this task and therefore ignores this option. | N/A | ||||||||
| delegation-only (yes | no); | Specifies whether the associated stub or hint zone should be treated as a delegation-only type zone | yes | yes | yes | ||||||
| deny-answer-addresses { address_match_list; } [except-from { name-list; | Configures the server to filter out (drop) address (A or AAAA) query responses from external DNS servers where the address(es) contained in the answer section fall within the address_match_list definition to mitigate rebinding attacks. However all address answers where the query name matches the except-from name-list will be accepted. For example a server configured with deny-answer-addresses {192.0.2.0/24;} except-from {"ipamworldwide.com";}; will drop A records in the answer section containing an address within the 192.0.2.0/24 space except where the query name falls within the ipamworldwide.com domain or subdomain. | yes | yes | |||||||
| deny-answer-aliases { alias-list; } [except-from { name-list; | Configures the server to filter out (drop) alias (CNAME or DNAME) query responses from external DNS servers where the alias(es) contained in the answer section fall within the alias-list definition to mitigate rebinding attacks. However all alias answers where the query name matches the except-from name-list will be accepted. For example a server configured with deny-answer-aliases {"ipamworldwide.com";} except-from {"biz.worldwide.com";}; will drop CNAME or DNAME records within the answer section of the response containing an answer within the ipamworldwide.com domain or subdomains except where the query name falls within the biz.ipamworldwide.com domain or subdomains. | yes | yes | |||||||
| dialup (yes | no | notify | refresh | passive | notify-passive ); | Concentrates all communications between servers to the time when a dialup connection is made based on timing set in the heartbeat-interval option overriding the refresh timer to send out SOA (refresh) queries and NOTIFYs only at this interval. More granular control is available using:
| yes | yes | yes | yes | yes | ||||
| directory pathname; | "Specifies the location of current working directory on the server. Any relative (non-absolute) pathnames are interpreted as relative to this directory. If not specified the default is "".""." | yes | ||||||||
| disable-algorithms domain { algorithm; [ algorithm;] }; | Disables the specified DNSSEC algorithm(s) when processing queries for the specified domain and its subdomains. Multiple occurrences of this statement are permitted. | yes | yes | |||||||
| disable-ds-digests domain { digest_type; [ digest_type; ] }; | Disables specified DS/DLV digest types at and below the specified domain. Multiple statements are permitted. | yes | yes | |||||||
| disable-empty-zone zone_name; | Disables an individual empty zone identified by zone_name. Multiple statements are permitted. | yes | yes | |||||||
| dns64 IPv6_prefix { [clients {address_match_list };] [mapped {address_match_list };] [exclude {address_match_list };] [suffix IPv6_addr;] [recursive-only (yes|no);] [break-dnssec (yes|no);] }; | Supports the DNS64 IPv4-IPv6 co-existence strategy by allowing an IPv6 host to connect to an IPv4 destination via a NAT64 gateway whose IP address is a concatenation of the specified IPv6 prefix and a IPv4 address returned via A record queries (when no native AAAA record answers are provided). The DNS64 service provides this mapping function. This option configures the recursive server to return mapped IPv4 addresses to AAAA queries when A but no AAAA answers are received from the authoritative server . The resolver receiving such an answer shall connect to a NAT64 device at this address; the NAT64 device links the incoming IPv6 connection from the resolver client to the corresponding mapped IPv4 address encoded in the IPv6 destination address based on the AAAA response provided by the DNS64 service. The clients parameter indicates an address match list of clients for whom the service is provided; the default is any. The mapped parameter indicates which IPv4 addresses within the A resource record set shall be mapped to corresponding AAAA answers. The exclude parameter defines which queried IPv6 networks will return DNS64-translated AAAA records (based on A records returned) will be returned not native AAAA records; normally native AAAA records are returned obviating the need to return DNS64 fabricated AAAA records. The suffix can be used to specify addiitional bits to include in the mapped response following the IPv4 address (default is ::). The recursive-only parameter indicates whether to apply DNS64 mapping to recursive queries only and the break-dnssec will not add or remove records from the authoritative server response if no and will do so if yes. | yes | yes | |||||||
| dns64-contact name ; | Supports the DNS64 IPv4-IPv6 co-existence strategy as discussed above. This option defines the administrative contact name that will appear in the SOA record for the ipv6.arpa zone corresponding to the mapped AAAA records created by appending the IPv4 address to the IPv6 prefix during a DNS64 transaction. | yes | yes | |||||||
| dns64-server name ; | Supports the DNS64 IPv4-IPv6 co-existence strategy as described above. This option defines the DNS server name that will appear in the SOA record for the ipv6.arpa zone corresponding to the mapped AAAA records created by appending the IPv4 address to the IPv6 prefix during a DNS64 transaction. | yes | yes | |||||||
| dnssec-accept-expired (yes | no); | Instructs the server to accept expired signatures for DNSSEC validation. The default is no. | yes | yes | |||||||
| dnssec-dnskey-kskonly (yes | no); | This option is a parameter for BIND's automated DNSSEC key and signature management features. When set to yes and update-check-ksk is set to yes only KSKs will be used to sign the DNSKEY RRset at the zone apex; otherwise ZSKs may be used to sign the DNSKEY RRset. When update-check-ksk is set to no this option is ignored. | yes | yes | yes | yes | |||||
| dnssec-enable (yes | no); | Turns on DNNSEC processing on the server when set to yes The default is yes. | yes | yes | |||||||
| dnssec-loadkeys-interval minutes; | Specifies the interval between checks for new keys or changes in key timing metadata when auto-dnssec maintain; is configured. The default is 60 (minutes) the minimum value is 1 and the maximum value is 1440. | yes | yes | yes | yes | |||||
| dnssec-lookaside (auto | domain trust-anchor DLV_domain); | Specifies parameters for DNSSEC Lookaside Validation (DLV). The DLV_domain serves as a domain escalation point for DNSSEC resolution signature validation where a signed zone's parent is not signed. If the query being resolved falls within the specified domain or its subdomains the associated public KSK key is retrieved from the DLV_domain server and compared with configured trusted-keys on this server to authenticate the resolution. The auto parameter initializes a managed key for the dlv.isc.org registry. | yes | yes | |||||||
| dnssec-must-be-secure domain (yes | no); | Specifies a domain (including subdomains) that must provide secure resolution as validated by trusted-key configuration or DLV when set to yes. When set to no secure resolution is not required for this domain. | yes | yes | |||||||
| dnssec-secure-to-insecure (yes | no); | When set to yes this allows the DNSKEY record(s) to be deleted in the zone(s) via BIND's automated DNSSEC key and signature management features introduced in BIND 9.7.0. Deleting these records effectively transitions the zone(s) from secure to insecure. | yes | yes | yes | ||||||
| dnssec-update-mode (maintain | no-resign); | Configures automated signing of new or changed resource records and automated resigning of RRSets when nearing signature expiration when set to maintain. When set to no-resign new or changed resource records will be signed but automated resigning of RRSets when nearing signature expiration will be disabled. | yes | yes | |||||||
| dnssec-validation (yes | no | auto); | Turns on DNSSEC validation processing when set to yes. dnssec-enable must also be set to yes. The default is yes. | yes | yes | |||||||
| dnstap { message_type; ... }; | Defines message types to be logged under the dnstap query logging feature. Message type can be client, auth, resolver, forwarder, or all. | yes | yes | |||||||
| dnstap-output ( file | unix ) path_name; | dnstap logging destination including specification of destination as a file or a UNIX domain socket followed by the path of the file or socket. | yes | ||||||||
| dnstap-identity ( string | hostname | none ); | Defines an identity to include in dnstap messages. The default is hostname, i.e., the server's hostname. | yes | ||||||||
| dnstap-version ( string | none ); | Specifies a version string to inclue in dnstap messages. | yes | ||||||||
| dscp ip_dscp; | Specifies the value of the differentiated services code point (DSCP) in the IPv4 header to classify outgoing DNS traffic on operating systems that support DSCP. Valid values for ip_dscp are 0-63 and the default is "not configured". | yes | yes | yes | yes | |||||
| dual-stack-servers [port port] [dscp ip_dscp ] { (domainname [port port] [dscp ip_dscp ] |IP_address [port port] [dscp ip_dscp ] ); ... }; | Specifies external name server IP addresses or hostnames that have access to both IPv4 and IPv6 transport. This option has no effect if the server on which this option is configured is itself dual-stacked. | yes | yes | |||||||
| dump-file pathname; | Specifies the file pathname to place the dump file when told to dump its database via rndc dumpdb; the default is named_dump.db | yes | ||||||||
| edns-udp-size bytes; | Defines the advertised EDNS UDP buffer size in bytes ranging from 512 to 4096 (default) | yes | yes | |||||||
| empty-contact name; | Specifies the zone contact that will appear in the SOA record created in empty zones. If not specified "." is used. | yes | yes | |||||||
| empty-server name; | Specifies the server name that will appear in the SOA record created in empty zones. If not specified the empty zone's name will be used. | yes | yes | |||||||
| empty-zones-enable (yes | no); | Enables (yes) or disables (no) creation of empty zones on the server. Empty zones are enabled by default. | yes | yes | |||||||
| fake-iquery (yes | no); | Obsolete - indicates the server should emulate DNS query type IQUERY which has been deprecated; BIND 9 never simulates IQUERYs | N/A | ||||||||
| fetch-glue (yes | no); | Obsolete - Stops the server from fetching glue records to include in the additional section of the query response when set to no. BIND 9 never fetches glue records. | N/A | N/A | |||||||
| fetch-quota-params number low high discount; | Defines parameters for the dynamic resizing of the fetches-per-server option in response to detected congestion. The number parameter indicates how often the moving average ratio of timeouts to responses should be calculated based on the number of queries received (default = 100 queries). The remaining arguments define the low ratio threshold (default 0.1), the high threshold (default 0.3) and the discount parameter (default 0.7) respectively where a higher discount weighs more recent events higher than earlier events. This option requires BIND to be built with configure -enable-fetchlimit. | yes | yes | |||||||
| fetches-per-server number [(drop | fail)]; | Defines the maximum number of simultaneous iterative queries that may be sent to a single name server. The default is 0 which indicates no limit. This quota is dynamically adjusted based on the setting of the fetch-quota-params option. The optional drop or fail keyword indicates whether the server shall drop those queries exceeding the quota with no response or respond with a SERVFAIL. The default is fail. | yes | yes | |||||||
| fetches-per-zone number [(drop | fail)]; | Defines the maximum number of simultaneous iterative queries that may be sent for a given domain. The default is 0 which indicates no limit. This quota is dynamically adjusted based on the setting of the fetch-quota-params option. The optional drop or fail keyword indicates whether the server shall drop those queries exceeding the quota with no response or respond with a SERVFAIL. The default is fail. | yes | yes | |||||||
| file filename; | Identifies the zone filename for the specified zone | yes | yes | yes | yes | yes | ||||
| files number; | Defines the maximum number of files the DNS service may have open concurrently. The default is unlimited. | yes | ||||||||
| filter-aaaa {addr_match_list;} ; | Defines the address match list for which the filter-aaaa-on-v4 and filter-aaaa-on-v6 options are applied as described below. Multiple filter-aaaa options may be defined. The default is any. | yes | ||||||||
| filter-aaaa-on-v4 (yes | no | break-dnssec) ; | Defines whether the server will return AAAA records to certain IPv4 clients. For example clients that do not have IPv6 network access can be excluded. Such clients are defined by the address match list parameter of the filter-aaaa option. BIND must be compiled with the --enable-filter-aaaa option on the configure command line. If this option is set to yes AAAA records are not included in the response if the client falls within the filter-aaaa address match list and no DNSSEC signatures are included. If set to no such filtering is not performed and AAAA records are returned. If set to break-dnssec the AAAA records are not included even if DNSSEC signatures exist. | yes | ||||||||
| filter-aaaa-on-v6 (yes | no | break-dnssec) ; | Defines whether the server will return AAAA records to certain IPv6 clients. For example clients that do not limit IPv6 network access can be excluded. Such clients are defined by the address match list parameter of the filter-aaaa option. BIND must be compiled with the --enable-filter-aaaa option on the configure command line. If this option is set to yes AAAA records are not included in the response if the client falls within the filter-aaaa address match list and no DNSSEC signatures are included. If set to no such filtering is not performed and AAAA records are returned. If set to break-dnssec the AAAA records are not included even if DNSSEC signatures exist. | yes | ||||||||
| flush-zones-on-shutdown (yes | no); | When signaled to exit via the SIGTERM signal the server will discard any pending zone writes from journal files; the default is no indicating zone writes should first be performed | yes | ||||||||
| forward (only | first); | Configures the server to either:
| yes | yes | yes | yes | yes | yes | |||
| forwarders { [IP_address [port port] [dscp ip_dscp]; ] }; | Specifies the IP address(es) of servers to query when using forwarding. The default is an empty list i.e. no forwarding but when the empty list is used within a zone statement while forwarders are configured within the server options statement then those forwarders are enabled on the server but not for the zone with the empty forwarders list (i.e. acts as negation). | yes | yes | yes | yes | yes | yes | |||
| fstrm-set-buffer-hint number ; | Configures the threshold number of bytes to accumulate in the output buffer before forcing a buffer flush in the high speed framing library, libfstrm used by dnstap. The minimum is 1024, the maximum is 65536, and the default is 8192. | yes | ||||||||
| fstrm-set-flush-timeout number ; | Defines the number of seconds to allow unflushed data to remain in the output buffer in the high speed framing library, libfstrm used by dnstap. The minimum (and default) is 1 second, the maximum is 600 seconds (10 minutes). | yes | ||||||||
| fstrm-set-input-queue-size number ; | Specifies the number of queue entries to allocate for each input queue for the high speed framing library, libfstrm used by dnstap. This value must be a power of 2. The minimum is 2, the maximum is 16384, and the default is 512. | yes | ||||||||
| fstrm-set-output-notify-threshold number ; | The number of outstanding queue entries to allow on an input queue before waking the I/O thread for the high speed framing library, libfstrm used by dnstap. The minimum is 1 and the default is 32. | yes | ||||||||
| fstrm-set-output-queue-model ( mpsc | spsc ) ; | Controls the queuing semantics to use for queue objects for the high speed framing library, libfstrm used by dnstap. The default is mpsc (multiple producer, single consumer); the other option is spsc (single producer, single consumer). | yes | ||||||||
| fstrm-set-output-queue-size number ; | Defines the number of queue entries to allocate for each output queue for the high speed framing library, libfstrm used by dnstap. The minimum is 2, the maximum is system-dependent, and the default is 64. | yes | ||||||||
| fstrm-set-reopen-interval number ; | Defines the number of seconds to wait between attempts to reopen a closed output stream for the high speed framing library, libfstrm used by dnstap. The default is 5 seconds, the minimum is 1 second, and the maximum is 600 seconds (10 minutes). | yes | ||||||||
| geoip-directory pathname; | Defines the directory containing the GeoIP .dat database files for GeoIP initialization. By default this option is not configured and the libGeoIP built-in directory is used for GeoIP features. | yes | yes | |||||||
| geoip-use-ecs (yes | no); | Configures the server to use the EDNS client subnet (ecs) option if present for matching against the GeoIP database when BIND is compiled with GeoIP support and configured with geoip ACLs. | yes | yes | |||||||
| has-old-clients (yes | no); | Ignored in BIND 9 but its effect can be achieved using auth-nxdomain yes; and rfc2308-type1 no; | yes | ||||||||
| heartbeat-interval minutes; | Defines the heartbeat interval governing frequency of tasks for zones defined with the dialup option set to a value other than no (default = 60 [minutes]). | yes | ||||||||
| host-statistics (yes | no); | Not implemented in BIND 9 - stimulates statistics tracking for each host interacting with the server | N/A | ||||||||
| host-statistics-max number; | Not implemented in BIND 9 - specified the maximum number of host statistics entries permitted in BIND 8. | N/A | ||||||||
| hostname hostname_string; | Defines a host name to be provided in response to a TXT query of class CHAOS for owner hostname.bind. The default is the hostname of the server on which named is running as determined by a gethostname() call. Setting hostname_string to none disables processing of these queries. | yes | ||||||||
| interface-interval minutes; | Defines the interval governing the frequency of scans for new or removed network interfaces on the server to begin listening on new interfaces and stop listening on deleted interfaces as permitted with corresponding listen-on settings. The default is 60 [minutes]. | yes | ||||||||
| ixfr-from-differences ((yes | no) | master | slave); | When set to yes the server will compute the differences between a new version of a zone (upon reload as a master or zone transfer receipt as a slave) and use the differences between these for IXFR processing. The parameters master and slave may be defined at the view and zone statements to apply this processing to master zones or slave zones respectively within the view or zone. | yes | yes | yes | yes | |||||
| ixfr-tmp-file pathname; | Specifies the file pathname for a temp file for IXFRs | yes | yes | |||||||
| journal pathname; | Specifies the pathname of the journal file. | yes | yes | |||||||
| keep-response-order { address_match_list }; | Specifies the set of addresses with the address match list to which the server will send responses to TCP queries in the same order in which they were received. The default is none. | yes | ||||||||
| key-directory pathname; | The full directory pathname in which public and private key files are stored on the server for processing of dynamic updates of DNSSEC secure zones. If not specified the current working directory is used. | yes | yes | yes | yes | |||||
| lame-ttl seconds; | Defines the number of seconds the server will cache a lame server designation; i.e. a given server is not authoritative for a zone that's delegated to it (default = 600 [seconds]). | yes | yes | |||||||
| listen-on [port port] [dscp ip_dscp] { address_match_list }; | Specifies the network interface the server listens for queries; the default is to listen on port 53 on all interfaces. Multiple listen-on statements may be defined. | yes | ||||||||
| listen-on-v6 [port port] [dscp ip_dscp] { address_match_list }; | Specifies the network interface parameters on which the server will listen for queries using IPv6 transport. If this option is not specified the server will not listen on any of the server's IPv6 addresses unless BIND was invoked with the -6 option when it will listen on all IPv6 interfaces. | yes | ||||||||
| lock-file path_name; | Specifies the pathname of a file on which named will attempt to acquire a file lock when starting up for the first time as confirmation another server is not already running. Setting path_name to none disables this feature and the default is /var/run/named/named.lock. | yes | ||||||||
| maintain-ixfr-base (yes | no); | Obsolete - indicated that server should keep a transaction log for IXFRs; such logging is enabled in BIND 9. | N/A | N/A | N/A | N/A | |||||
| managed-keys-directory directory; | The directory in which files used to track managed keys are located. By default this is the named working directory. | yes | ||||||||
| masterfile-format (text | raw | map); | Specifies the format of zone files on the server. The default is text. Setting to raw will omit some name checking features and setting to map uses an image of a BIND 9 in-memory zone database but is very server architecture specific. | yes | yes | yes | yes | yes | yes | |||
| masterfile-style (relative|full) ; | When masterfile-format is set to text, this option specifies whether a dump of the zone files is formatted in multi-line format with owner names expressed relative to a shared origin when set to relative which may be easier for human consumption or with fully qualified owner names when set to full which may be easier for script processing. | yes | yes | |||||||
| masters [port port ] [dscp ip_dscp] { ( masters_list | ip_address [port port] [key key] ); [. . .] }; | Identifies the master name servers for the given zone including specification of the outgoing port number for SOA queries and zone transfers (port specification before the curly brackets). This statement also specifies the zone master server's name or IP address port and TSIG key to authenticate zone transfers. | yes | yes | yes | ||||||
| match-mapped-addresses (yes | no); | Specifies that the server should map IPv4 addresses associated with an IPv4-mapped IPv6 address against defined address match lists for processing. This option is intended solely for use as a work around for a Linux kernel quirk for IPv6-enabled Linux servers. | yes | ||||||||
| max-acache-size size; | Sets the maximum memory size to be used for the server's additional section cache (acache) in bytes. When the amount of data in the cache approaches the limit the server will prematurely expire records to remain within the bound. The default = unlimited. | yes | yes | |||||||
| max-cache-size size; | Sets the maximum memory size to be used for the server's cache. If using DNS views the specified size applies to the cache size for each view. When the amount of data in the cache approaches the limit the server will prematurely expire records to remain within the bound (default = 0 which means that records are purged from cache when their TTLs expire). | yes | yes | |||||||
| max-cache-ttl number; | Defines the maximum retention time for cached [positive] information. The default is 7 days. | yes | yes | |||||||
| max-clients-per-query number; | Defines the maximum number of simultaneous outstanding recursive queries for a given name (i.e. of the same qname qtype qclass) before dropping additional clients. In this context the server issuing such queries is the "client" referred to by the option name (default = 100). | yes | yes | |||||||
| max-ixfr-log-size number; | Obsolete in BIND 9 and is ignored. The max-journal-size option performs a similar function in managing sizing of updates. | yes | yes | yes | yes | |||||
| max-journal-size size; | Specifies the maximum size of each journal file. The default is unlimited. | yes | yes | yes | yes | |||||
| max-ncache-ttl seconds; | Defines the maximum number of seconds the server will cache negative answers. The default is 10800 [seconds] or 3 days and the maximum value is 7 days. | yes | yes | |||||||
| max-recursion-depth number; | Defines the maximum number of resolution redirections permitted for a given query. A redirection occurs when resolving a domain name requires the resolution of another name. The default is 7. | yes | yes | |||||||
| max-recursion-queries number; | Defines the maximum number of iterative queries that may be sent for a given recursive query. The root and TLD iterative queries are not counted against this max and the default is 75. | yes | yes | |||||||
| max-refresh-time seconds; | Defines the maximum refresh interval for SOA refresh attempts to the master. | yes | yes | yes | yes | yes | ||||
| max-retry-time seconds; | Defines the maximum retry time at which the server should retry a failed zone transfer. | yes | yes | yes | yes | yes | ||||
| max-rsa-exponent-size number ; | Defines the maximum RSA exponent size that will be accepted when validating DNSSEC responses (in bits). Valid values are 0 (default, equivalent to 4096), 35 to 4096. | yes | ||||||||
| max-transfer-idle-in minutes; | Specifies a limit on the duration of idle time during an inbound zone transfer (default = 60 [minutes]). Once exceeded the zone transfer will be terminated. | yes | yes | yes | yes | |||||
| max-transfer-idle-out minutes; | Specifies a limit on the duration of idle time during an outbound zone transfer (default = 60 [minutes]). Once exceeded the zone transfer will be terminated. | yes | yes | yes | yes | |||||
| max-transfer-time-in minutes; | Specifies a limit on the duration of an inbound zone transfer (default = 120 [minutes]). Once exceeded the zone transfer will be terminated. | yes | yes | yes | yes | |||||
| max-transfer-time-out minutes; | Specifies a limit on the duration of an outbound zone transfer (default = 120 [minutes]). Once exceeded the zone transfer will be terminated. | yes | yes | yes | yes | |||||
| max-udp-size bytes | Defines the maximum EDNS UDP packet size the server will send in bytes ranging from 512 to 4096 (default) | yes | yes | |||||||
| max-zone-ttl (unlimited | sec) | Defines the maximum permissible TTL value for all zones or a particular zone on the server. This is useful when rolling DNSSEC keys to to enable the to-be-rolled key to remain available until corresponding RRSIG records have expired from cahces. | yes | yes | yes | yes | |||||
| memstatistics (yes | no); | Turns on (yes) or off (no) writing of memory statistics to the file specified in the memstatistics-file option. The default is no unless named was started with the "-m record" switch. | yes | ||||||||
| memstatistics-file pathname; | This specifies the pathname of the file to which the server will write memory usage statistics. The default is named.memstats. | yes | ||||||||
| message-compression yes_or_no ; | Configures the server to use DNS name compression for regular queries (compression is always used for incremental or absolute zone transfers) | yes | ||||||||
| min-refresh-time seconds; | Defines the minimum SOA refresh time to query the master. | yes | yes | yes | yes | yes | ||||
| min-retry-time seconds; | Defines the minimum retry time at which the server should retry a failed zone transfer. | yes | yes | yes | yes | yes | ||||
| min-roots number; | Not implemented in BIND 9. This option defines the minimum number of root servers configured within the hints file in order for the server to answer any queries regarding the root servers. This defines a minimum credibility threshold of the server's ability to respond to such queries. The default is 2. | N/A | N/A | |||||||
| minimal-any (yes | no); | This option governs responses to ANY queries, i.e., RRType of "*" for a given qname. If set to yes, only one RRType (and associated DNSSEC signatures) for the queried name will be provided in the response instead of all RRTypes for the queried name if set to no (default). | yes | ||||||||
| minimal-responses ( yes | no | no-auth | no-auth-recursive ); | When set to yes this option instructs the server to only add records to the authority and additional sections of the response when required e.g. for negative responses or delegations. When set to no-auth, the server will only add records to the authority section if required but may add records to the additional section. When set to no-auth-recursive, limiting of authority and additional section resource records applies to recursive queries. The default is no. | yes | yes | |||||||
| multi-master (yes | no); | When set to yes the server will not log when its serial number is greater than that on another master | yes | yes | yes | ||||||
| multiple-cnames (yes | no); | Ignored in BIND 9 which disallows multiple CNAME records with the same owner name; in BIND 8 this option allows multiple CNAME records for a single name | N/A | ||||||||
| named-xfer pathname; | This option is not used in BIND 9 but it specified the directory path for named-xfer file (used by a slave server for inbound zone transfers). | N/A | ||||||||
| no-case-compress {addr_match_list }; | Responses to queriers within the scope of the address match list will include non-compression of case-sensitive answers. With case compression (default), example.com and example.COM are the same and hence compressed; with no-case-compression, both versions of the answer are included in the response. | yes | yes | |||||||
| nocookie-udp-size number ; | Defines the maximum size in bytes of UDP responses to queries without a valid server cookie. The default is 4096 but the max-udp-size option may further limit the response size. | yes | yes | |||||||
| notify (yes | no | explicit | master-only); | This option governs the sending of NOTIFY messages:
| yes | yes | yes | yes | |||||
| notify-delay seconds; | This option defines the number of seconds to wait between sending sets of Notify messages. The default is 0. | yes | yes | yes | yes | |||||
| notify-rate number; | This option defines the rate of notify requests per second. The default is 20. | yes | ||||||||
| notify-source (IPv4_address | *) [port port ] [dscp ip_dscp]; | Defines the server's network interface (IPv4 address) and optionally source UDP port for sending Notify messages. | yes | yes | yes | yes | |||||
| notify-source-v6 (IPv6_address | *) [port port ] [dscp ip_dscp]; | Defines the server's network interface (IPv6 address) and optionally source UDP port for sending Notify messages. | yes | yes | yes | yes | |||||
| notify-to-soa (yes | no); | Facilitates hidden master configurations when set to yes by instructing the server to send a Notify message as appropriate to the server listed in the SOA record master name (MNAME) field. In hidden master configurations MNAME may be configured with the name of a slave server. If set to no a Notify will not be sent to the server listed in the MNAME field. | yes | yes | yes | yes | |||||
| nta-lifetime duration ; | This parameter configures the default time that a negative trust anchor (nta) is ignored when added via rndc nta. An nta disables DNSSEC validation for zones known to be failing validation due to misconfiguration. The duration may be entered using TTL-style formats for seconds, minutes or hours. The default is one hour. | yes | yes | yes | yes | |||||
| nta-recheck duration ; | Negative trust anchor (nta) configuration enables you to disable DNSSEC validation for a given domain due to know misconfiguration issues. Named will periodically issue a query to each nta domain to determine if it has been repaired, i.e., whether DNSSEC validation is accurate. This option sets the duration of the periodicity of these checks. These checks can be disabled by setting the valude to 0; the default is 5s. | yes | ||||||||
| nxdomain-redirect string; | Defines a redirect namespace to replace an NXDOMAIN received from an authoritative server with the original query name plus the specified string. If a relevant zone of type redirect is defined, it shall override the setting of this option. | yes | ||||||||
| pid-file (pathname | none); | Specifies the pathname of the file to which the server writes its process ID. The default is /var/run/named.pid (pre BIND 9.6) or /var/run/named/named.pid (BIND 9.6+). If the pathname parameter is specified as none no pid file will be written. | yes | ||||||||
| port port; | Specifies the UDP/TCP port number used by the server for sending and receiving DNS messages. This option is intended primarily for server testing purposes as setting the value to other than 53 the default will inhibit communications with the global DNS | yes | ||||||||
| preferred-glue (A | AAAA | NONE ) ; | Specifies the preferred resource record type that will be specified first in the additional section of a query response for an NS record. The default is NONE no preference. | yes | yes | |||||||
| prefetch number [ number ] ; | Specifies whether the server should refresh its cache for soon-to-expire cached data ensuring the cache always has an answer. The number parameter defines the trigger TTL at which prefetch will take place when a cached record with a lower TTL is encountered durign query processing. The default value is 0 which disables prefetch and other valid values are 1-10. The second optional parameter defines the eligibility TTL, or the smallest original TTL value that will be accepted for eligibility for prefetch. The default value is 9 and the value must be at least six seconds greater than the trigger TTL value. | yes | yes | |||||||
| provide-ixfr (yes | no); | Used in options or server statements to configure a server configured as master for its zones to honor IXFR requests from slaves or not. | yes | yes | |||||||
| pubkey flags protocol algorithm publickey; | Ignored in BIND 9 - specifies a public key (similar subfields as a DNSKEY resource record) for the associated zone. | N/A | N/A | N/A | ||||||
| query-source (IPv4_address | *) [port (port |*)] [dscp ip_dscp] | [address (IPv4_address | *)] [port (port |*)] [dscp ip_dscp]; | Defines the local network interface (IPv4 address) and source port for UDP-based queries issued to other servers to obtain a query answer TCP-based queries always use a random source port and it's recommended that UDP also do so to reduce the risk of cache poisoning. Therefore the port parameter should generally not be specified. | yes | yes | |||||||
| query-source-v6 (IPv6_address | *) [port (port |*)] [dscp ip_dscp] | [address (IPv6_address | *)] [port (port |*)] [dscp ip_dscp]; | Defines the local network interface (IPv6 address) and source port for UDP-based queries issued to other servers to obtain a query answer TCP-based queries always use a random source port and it's recommended that UDP also do so to reduce the risk of cache poisoning. Therefore the port parameter should generally not be specified. | yes | yes | |||||||
| querylog ( yes | no ); | When set to yes logging of queries is enabled upon named startup; query logging is otherwise determined by the queries logging category setting. | yes | ||||||||
| queryport-pool-ports number; | Obsolete. Specifies the number of candidate ports randomly generated for use for setting of the IP port on outgoing queries. The default is 8 port numbers. (Obsoleted with port randomization feature) | N/A | N/A | |||||||
| queryport-pool-updateinterval minutes; | Obsolete. Specifies the number of minutes between refreshes of the query port pool. When minutes has elapsed the query port pool is regenerated. The default is 15 minutes. | N/A | N/A | |||||||
| random-device pathname; | Specifies the device or file used as a source of entropy or random data primarily for DNSSEC operations such as key generation for dynamic updates of secure zones | yes | ||||||||
| recursing-file pathname; | Specifies the pathname to the file in which named dumps the set of currently recursing queries when so instructed via the rndc recursing command. The default is named.recursing. | yes | ||||||||
| recursion (yes | no); | Turn recursion on or off. If set to yes the server will perform recursion to obtain the answer for the client; if no the server will attempt to give an authoritative answer cached information or a referral to another name server. | yes | yes | |||||||
| recursive-clients number; | Defines the maximum number of simultaneous recursive lookups the server will perform on behalf of clients (default = 1000). | yes | ||||||||
| request-expire (yes | no);; | Configures the server to request the EDNS EXPIRE value from its master server. This value indicates the time remaining until the zone expires if not refreshed. The use case for this option applies when a server, configured as a slave requests zone transfers from another slave. The default is yes. | yes | yes | |||||||
| request-nsid (yes | no); | When set to yes, an empty EDNS0 Name Server Identifier (NSID) option is sent with all queries to authoritative name servers during iterative name resolution. Returned NSID values are logged in the resolver logging category at level info. Default = no. | yes | ||||||||
| request-ixfr (yes | no); | Used in options or server statement to configure a slave to request IXFRs of its master or not. | yes | yes | yes | ||||||
| request-sit (yes | no); | This experimental option is obsolete. | |||||||||
| require-server-cookie (yes | no); | Configures the server to require a valid server cookie within a query from a cookie aware client before sending a full response in reply. The BADCOOKIE error is sent if the cookie is absent or invalid. | yes | ||||||||
| reserved-sockets number; | Enables specification of the number of file descriptors supported by the operating system to keep named within this constraint (Default =512). | yes | ||||||||
| resolver-query-timeout seconds; | Enables specification of the number of seconds the server should await a response to a query before failing (SERVFAIL). The default is 10 and the maximum is 30. | yes | ||||||||
| rate-limit { [responses-per-second number ;] [referrals-per-second number ;] [nodata-per-second number ;] [nxdomains-per-second number ; ] [errors-per-second number ; ] [all-per-second number ; ] [window number ; ] [log-only (yes | no) ; ] [qps-scale number ; ] [ipv4-prefix-length number ; ] [ipv6-prefix-length number ; ] [slip number ; ] [exempt-clients {addr_match_list} ; ] [max-table-size number ; ] [min-table-size number ; ] }; | Enables specification of parameters designed to minimize the use of this server in amplifying reflection denial of service attacks which inundate a spoofed (target) IP address. The server will limit nearly identical answers for a given IP address (or addresses within a block if ipv4-prefix-number (default = 24) or ipv6-prefix-number (default = 56) are specified and/or for a given namespace is a domain is specified. Responses by type (responses, referrals, nodata, nxdomains or errors) or all can be limited based on the quantity of responses already provided as specified in the respective "per-second" parameter. The qps-scale parameter dampens the responses/errors/nxdomains or all per second values to tighten defenses during an attack based on the overall query rate. For example if qps-scale is set to 250 and responses-per-second is 20, then a total query rate of 1000 qps changes the effective responses-per-second to (250/1000)*20 = 5. The optional parameters on responses-per-second control initiation of rate limiting to response or amplification factors to minimum sizes. Size applies to the minimum response size that will trigger this parameter; ratio indicates the policy applies for responses where the response size/request size ratio exceeds this value. | yes | yes | |||||||
| response-policy { specifications } ; | Also known as "DNS Firewall," this option enables specification of modified responses to queries for the specified zone in accordance with the response policy zone initiative where domain registrars may share valid (e.g. non-spammers) domain names to enable resolution while not resolving others modifying or otherwise processing responses for "invalid" domain names as identified via backlist/whitelist queries. Please consult our DNS firewall section for specification details. | yes | yes | |||||||
| rfc2308-type1 (yes | no); | Not yet implemented. Specifies that the server should send the zone's NS records with SOA in negative responses for the zone. | N/A | N/A | |||||||
| root-delegation-only [ exclude { namelist } ] ; | Enables enforcement of delegation-only processing in root and TLDs except those domains listed within the namelist after the exclude keyword. | yes | yes | |||||||
| rrset-order { order-stmt ; [ order-stmt; ]};
where: order-stmt =[ type rrtype] [name domainname] order ordertype
| Enables specification of ordering of resource records when multiple records apply to the query. The rrtype parameter refers to a resource record type (e.g. MX) and domainname a given domain name (e.g. ipamworldwide.com). Ordering (ordertype) may be:
Note: the fixed ordertype has not yet been fully implemented in BIND 9. | yes | yes | |||||||
| secroots-file pathname; | Specifies the pathname of the file to which rndc secroots command dumps security roots. (default = named.secroots). | yes | ||||||||
| send-cookie (yes | no); | Configures the server to send an EDNS COOKIE with each query to provide identification to the queried server to avoid potential rate limiting treatment. | yes | ||||||||
| serial-update-method increment|unixtime|date; | Configures the server with the zone serial number format in its SOA record. Setting to increment sets the format to a monotontically increasing integer. The unixtime format indicates the number of seconds since the UNIX epoch unless the serial number is already greater than this value, in whihc case it is incremented by 1. The date method defines the serial number format as YYYYMMDDXX where XX is an incremented value from 00 to 99. | yes | yes | |||||||
| serial-queries number; | Ignored in BIND 9 and superseded with the serial-query-rate option. This option had specified the maximum number of outstanding serial number queries. | N/A | ||||||||
| serial-query-rate number_per_second; | Specifies the maximum number of serial number queries per second to be sent to the master (across all zones) (default = 20). | yes | ||||||||
| serial-update-method (increment | unixtime); | Defines how the zone serial number will be updated when the zone changes upon receipt of a DDNS update. When set to increment the serial number will be incremented by one upon each update. When set to unixtime the serial number will be set to the current number of seconds since the Unix epoch. If the serial number value is already greater than current Unix time the serial number will be incremented by one. | yes | ||||||||
| server-addresses {[IP_address; ... ]}; | Configures the name server IP addresses (IPv4 and/or IPv6) configured for this static-stub zone. | yes | ||||||||
| server-id server-id_string; | Specifies the ID that the server should provide in response to a name server identifier (NSID) query or a query for owner ID.SERVER of type TXT in class CHAOS. This information can be helpful in identifying the responding server in an anycast deployment. Defining the server-id_string as none (the default) disables responses to such queries and setting it to hostname returns the configured hostname (per gethostbyname() sockets call). | yes | ||||||||
| server-names {[namelist ]}; | Configures the name server host domain names (NS rdata fields) configured for this static-stub zone. | yes | ||||||||
| servfail-ttl number; | Defines the number of seconds to cache a SERVFAIL response due to DNSSEC validation or other server failure. This cache is ignored for queries with the Checking Disabled (CD) bit set to enable querying without validation if desired. The default is 1s, a value of 0 disables such caching and the maximum value is 30s. | yes | ||||||||
| session-keyalg algorithm; | When BIND's pre-defined update-policy local; is configured named automatically creates a TSIG key to sign local dynamic updates. By default the key generation algorithm is HMAC-SHA256 but this option enables overriding this default. Valid values of algorithm are: hmac-sha1 hmac-sha224 hmac-sha256 hmac-sha384 and hmac-md5. | yes | ||||||||
| session-keyfile pathname ; | When BIND's pre-defined update-policy local; is configured named automatically creates a TSIG key to sign local dynamic updates. By default the file is /var/run/named/session.key though an alternative pathname may be defined using this option. | yes | ||||||||
| session-keyname keyname; | When BIND's pre-defined update-policy local; is configured named automatically creates a TSIG key to sign local dynamic updates. By default the keyname is local-ddns though this option may be specified to define a different keyname. | |||||||||
| sig-signing-nodes integer; | Specifies the maximum number of "nodes" (unique RRSet owners) that are examined during a zone re-signing evaluation to determine if re-signature is required or not for each. The default is 100. | yes | yes | yes | yes | |||||
| sig-signing-signatures number; | Specifies the maximum number of RRSets that will be re-signed during an automatic re-signing process. This option bounds the number of signatures performed during a re-sign. The default is 10. | yes | yes | yes | yes | |||||
| sig-signing-type integer; | Specifies the RData Type to be used when generating key signing records. The default is 65535. | yes | yes | yes | yes | |||||
| sig-validity-interval days [re-sign]; | Defines the expiration date as the number of days in the future for DNSSEC signatures automatically generated for dynamic updates to a secure zone. The default is 30 days and the maximum value is 10 years. The re-sign parameter defines the remaining time on RRSet signatures within which the server should re-sign the RRSet. If days is < 7 then re-sign is defined in units of hours; otherwise it is in days. If re-sign is not specified days/4 will be used as the assumed re-sign value. | yes | yes | yes | yes | |||||
| sortlist { address_match_list }; | Enables specification of the order of query responses based on source of query respond with preferred list of responses. Here are the details on the syntax and interpretation of the sortlist option. | yes | yes | |||||||
| stacksize size; | Defines the maximum size of stack memory the server may use. The default is default which is the amount of stack memory allocated by the operating system by default. | yes | ||||||||
| startup-notify-rate number; | Defines the rate of Notify requests sent when the name server is first starting up or when zones have been newly added. The default rate is 20 per second. | yes | ||||||||
| statistics-file pathname; | Specifies this pathname of the file to which the server appends statistics when the rndc stats command is executed. The default is named.stats. | yes | ||||||||
| statistics-interval minutes; | Defines the interval at which server statistics are logged. The default is 60 [minutes]. This option has not yet been implemented in BIND. | N/A | ||||||||
| suppress-initial-notify (yes | no); | This option has not yet been implemented in BIND. | N/A | N/A | |||||||
| tcp-clients number; | Limits number of concurrent TCP connections (default = 100). | yes | ||||||||
| tcp-listen-queue number; | Specifies the queue depth for listening for TCP connections (default and minimum = 3). | yes | ||||||||
| tkey-dhkey key_name key_tag; | This option specified the Diffie-Hellman key to use to generate shared keys with clients when using the Diffie-Hellman mode of TKEY. In most cases this should be the server's hostname. | yes | ||||||||
| tkey-domain domainname; | This option specifies the domainname that should be appended to the names of all shared keys generated during a TKEY exchange. In most cases the domainname should be the server's domain name. | yes | ||||||||
| tkey-gssapi-credential principal; | This option configures the credential to be used to authenticate keys for use with the GSS-TSIG protocol e.g. when performing secure updates to Microsoft Windows DNS. Currently a Kerberos principal is supported | yes | ||||||||
| tkey-gssapi-keytab pathname; | Defines the pathname to the key file used to authenticate Kerberos 5 credentials. If not set the typical system key file is /etc/krb5.keytab. | yes | ||||||||
| topology { address_match_list }; | Defines a preferential listing of networks defined within an address match list on which name servers will be queried. Click here for more on the interpretation of the topology option though this option has not yet been implemented in BIND. | N/A | N/A | |||||||
| transfer-message-size number; | Intended primarily for testing, this option defines a soft upper bound on uncompressed zone transfer messages over TCP. If the message size exceeds this bound, multiple messages will be sent unless the Rdata of a single resource record exceeds the bound it will be sent regardless. Valid values range from 512 to 65535 and the default is 20480. | yes | yes | |||||||
| transfer-format (many-answers | one-answer) ; | Specifies on a master server which format to employ for zone transfers: one-answer means one resource record per message while many-answers (the default) means multiple records as many as will fit within the message size are placed within each transfer message. | yes | yes | |||||||
| transfer-source (IPv4_address | *) [port port ] [dscp ip_dscp]; | Defines the server's network interface (IPv4 address and optionally port number) on which incoming zone transfers will be bound. This option also specifies the source IP address and optionally source UDP port for SOA query messages and forwarded dynamic updates. | yes | yes | yes | yes | |||||
| transfer-source-v6 (IPv6_address | *) [port port ] [dscp ip_dscp]; | Defines the server's network interface (IPv6 address and optionally port number) on which inbound zone transfers will be bound. This option also specifies the source IPv6 address and optionally source UDP port for SOA query messages and forwarded dynamic updates. | yes | yes | yes | yes | |||||
| transfers-in number; | Specifies a limit to the total number of concurrently running inbound zone transfers (default = 10). | yes | ||||||||
| transfers-out number; | Specifies a limit to the total number of concurrently running outbound zone transfers (default = 10). | yes | ||||||||
| transfers-per-ns number; | Specifies a limit on the number of concurrently running inbound zone transfers from any given server (default = 2) | yes | ||||||||
| treat-cr-as-space (yes | no); | Treat CR+NL at end of a line as simply NL to enable files created on Windows systems (CR_NL) to load on a Unix/Linux server. This option is ignored in BIND 9 as both NL and CR+NL forms are accepted. | N/A | ||||||||
| try-tcp-refresh (yes | no); | If a zone refresh query via UDP fails this option when set to yes configures the server to reattempt using TCP. The default is yes. | yes | yes | yes | ||||||
| update-check-ksk (yes | no); | Configures the server to use KSK(s) (KSK flag on the corresponding DNSKEY resource record is set) to sign the DNSKEY RRset only (if set to yes) or to ignore the KSK flag and use all zone keys to sign the zone (if set to no). The default of yes effectively requires the use of separate zone KSKs and ZSKs while a setting of no enables use of one key per zone. | yes | yes | yes | yes | |||||
| update-policy { grant|deny identity nametype name [types] }; | Enables specification of increased granularity of dynamic updates over and in lieu of allow-update. Please refer to the update-policy page for details. | yes | ||||||||
| use-alt-transfer-source (yes | no); | Controls the use of alternative transfer source options for v4 and v6 (alt-transfer-source and alt-transfer-source-v6 respectively). | yes | yes | yes | yes | |||||
| use-id-pool (yes | no); | Obsolete - BIND 9 always uses random DNS message IDs in queries to prevent response spoofing without having to set this option to yes. | N/A | ||||||||
| use-ixfr (yes | no); | Obsolete - BIND 9 always uses IXFR by default though use of IXFR can be controlled via provide-ixfr and request-ixfr statements in the options block or within a server statement block. | N/A | ||||||||
| use-queryport-pool (yes | no); | Obsolete. Configures the server to randomize the source IP port in queries to other servers. This option is overridden if the query-source or query-source-v6 option is configured. (Obsoleted with port randomization feature) | N/A | N/A | |||||||
| use-v4-udp-ports { port list; }; | Enables specification of a range or pool of port numbers from which a randomly selected value will be used to set the source port for outbound IPv4 queries. Values set in the avoid-v4-udp-ports option will be excluded from this port list for port number generation. The default range is 1024 65535. Note: Make sure your port range coincides with those permitted by the operating system on which named is running for named; otherwise queries using these port numbers will fail. | yes | ||||||||
| use-v6-udp-ports { port list; }; | Enables specification of a range or pool of port numbers from which a randomly selected value will be used to set the source port for outbound IPv6 queries. Values set in the avoid-v6-udp-ports option will be excluded from this port list for port number generation. The default range is 1024 65535. Note: Make sure your port range coincides with those permitted by the operating system on which named is running for named; otherwise queries using these port numbers will fail. | yes | ||||||||
| version version_string; | This option specifies the string the server should provide in response to give to a TXT query of class CHAOS for name version.bind. Setting version_string to "none" disables responding to these queries. | yes | ||||||||
| zero-no-soa-ttl (yes | no); | Instructs the server to set the TTL to zero when returning an authoritative negative response to an SOA query (default = yes). | yes | yes | yes | yes | |||||
| zero-no-soa-ttl-cache (yes | no); | Instructs the server when caching a negative response to an SOA query to set the TTL to zero (default = no). | yes | yes | |||||||
| zone-statistics (full | terse | none); | Instructs the server to collect statistical data on all zones (or per zone control/override in zone statement). These statistics can be accessed via the rndc stats command which appends them to the file identified in the statistics-file option. | yes | yes | yes | yes | yes | yes | yes |