DNS/DHCP Management Console

Additional Options for DNS

Use this tab to specify the additional global and server options.
To configure or modify an option, select the option and click Modify. To delete the value of an existing option, select the option and click Clear.

The following list of options are available:

additional-from-auth

Controls the behavior of an authoritative server while answering queries that have additional data, or when following CNAME and DNAME chains. Values can be either Yes or No. The default is Yes. When set to yes and a query is being answered from authoritative data (a zone configured to the server), the additional data section of the reply will be filled in using data from other authoritative zones.

additional-from-cache

Controls the behavior of an authoritative server while answering queries that have additional data, or following the CNAME and DNAME chains. Values can be either Yes or No. The default is Yes. When set to Yes and a query is being answered from authoritative data (a zone configured to the server), the additional data section of the reply will be filled in using data from the cache.

allow-notify

Specifies the list of hosts that are allowed to notify a slave DNS server of zone changes in addition to the zone masters. This option can be configured at the zone level. The value configured for zone will override the value specified here and is applicable for all zones for which this option is not configured.

cleaning-interval

Specifies the time (in minutes) for the server to remove expired resource records from the cache. The default interval is 60 minutes. If set to 0, no periodic cleaning will occur.

forward

Controls the behavior of queries for which the server is not authoritative and the answer do not exist in the cache. Values can be either First or Only. The default is First. If First is specified, the server will query the forwarders list first and, if the answer is not found, the server will search for the answer itself. If Only is specified, the server will query only the forwarders list.

lame-ttl

Specifies the time (in seconds) to cache a lame server indication.

Specifying a value of 0 disables caching. The maximum value is 1800 (30 minutes).

listen-on

Specifies the list of interfaces and ports that the server will listen on for queries. This option takes an optional port, and an address match list. If a port is not specified, port 53 will be used.

max-cache-ttl

Specifies the maximum time (in seconds) the server will cache ordinary (positive) answers.

max-ncache-ttl

Specifies the maximum time (in seconds) the server will cache negative answers. In order to reduce network traffic and increase performance the server stores negative answers. The maximum value is 7 days.

minimal-responses

Controls the responses generated by the server. Values can be either Yes or No. The default is No. If Yes is specified, the server will add records only to the authority and additional data sections when required (for example, delegations and negative responses). This might improve the performance of the server.

notify

Specifies whether this server has to send notifications of any zone data changes to slave servers. You can select from the following options:

This option can be configured at the zone level. The value configured for zone will override the value specified here and is applicable for all zones for which this option is not configured.

notify-source

Specifies the local source address and, optionally, the UDP port that are used to send notify messages. The local source address must appear in the slave servers' masters list or in an allow-notify list. Slave should also be configured to receive notify messages from this address.

This option can be configured at the zone level. The value configured for zone will override the value specified here and will be applicable for all zones for which this option is not configured.

novell_dyn-reconfig

Specifies the dynamic reconfiguration interval. The DNS server will automatically detect the configuration changes and the addition or removal of zone data, then update itself accordingly. The minimum value is 10 minutes and maximum is 24 hours.

provide-ixfr

Specifies whether the local server, acting as the master, will respond with an incremental zone transfer when the given remote server, a slave, requests it. Values can be either Yes or No. If set to Yes, incremental transfer will be provided whenever possible. If set to No, all transfers to the remote server will be non incremental.

query-source

Specifies the address and port number for querying other name servers when the server does not know the answer for the query.

recursion

Controls the recursion requests to answer DNS queries. If the recursion is turned off and the server is unable to query, a referral response is returned. Values can be either Yes or No. The default is Yes. If set to Yes, and a DNS query requests recursion, then the server will attempt to do all the work required to answer the query.

request-ixfr

Specifies whether the local server, acting as a slave, can request for an incremental zone transfer from the master server.

If set to Yes, the server requests an incremental zone transfer. IXFR requests sent to server that do not support IXFR will automatically fall back to AXFR.

rrset-order

Allows configuration of the ordering of the resource records in a RR set response. Values can be either random-cyclic or fixed. Fixed returns records in the order defined in the zone. Random-cyclic returns records in a random cyclic order.

serial-query-rate

Specifies the amount of the slave server's network bandwidth (in seconds) that a master server can use for query. The slave servers periodically query the master servers to find the change in serial numbers. You can limit the rate at which queries are sent in order to limit the amount of bandwidth used. The value can be an integer which is the maximum number of queries sent per second.

tcp-clients

Specifies the maximum number of simultaneous client TCP connections that the server can accept. The default value is 100.

transfer-format

Specifies the format of zone transfer. The transfer-format option is used on the master server to determine zone transfer format. Values can be either one-answer or many-answers. One-answer format uses only one DNS message per resource record transferred and many-answers uses more than one resource record per message transferred. Many-answers is more efficient.

transfer-source

Specifies the local addresses that are bound to IPv4 TCP connections used to search the zones transferred inbound by the server. It also specifies the source IPv4 address and, optionally, the UDP port. The UDP port is used to refresh queries and forward any dynamic updates.

If a value is not set, it defaults to a system-controlled value; usually, the address of the interface "closest to" the remote end.

transfers-in

Specifies the maximum number of zone-in transfers that can be executed simultaneously. Increasing the transfers-in might speed up the concurrence of slave zone, but it might also increase the load on the local system.

transfers-out

Specifies the maximum number of zone-out transfers that can be executed simultaneously. Zone transfer requests in excess of the limit will be refused.

transfers-per-ns

Specifies the maximum number of zone-in transfers that can be executed simultaneously from a remote name server. Increasing the value of this option might speed up the convergence of slave zones, but it also might increase the load on the remote nameserver.

zone-statistics

Specifies the statistical information that is dumped to the statistics-file for all zones in the server. Values can be either Yes or No. If set to Yes, the server will collect statistical data on all zones in the server. This option can be specified at the zone level. The value specified for zone will override the value specified here and will be applicable only for that zone.


Help Topics