SNMP Traps Option: SNMP traps are generated for various events depending on the configuration for this option. You can generate SNMP traps in the following modes:

Maximum Cache Size: Specifies the maximum amount of memory the server can use to cache responses. When the amount of data in the cache reaches this limit, the server causes existing records in cache to expire prematurely so that the limit is not exceeded. The default value is 0, which means an unlimited cache. That is, records are purged from the cache only when their TTLs expire.

Max Recursion Lookups: Allows you to configure the maximum number of simultaneous recursive lookups the server will perform on behalf of the clients. The default is 1000. The value of this option might need to be decreased on hosts with limited memory because each recursive lookup uses about 20 kilobytes of memory.

Zone Out Filter: Allows you to configure which hosts are allowed to receive zone transfers from the server. If hosts are not specified, the default is to allow transfers from all hosts. The Zone Out filter can be specified in the address match list format for the server.

Allow Recursion: Specifies which hosts are allowed to submit recursive queries to the server. If hosts are not specified, the default is to allow recursive queries from all hosts. Allow recursion can be specified in the address match list format.

Query Filter: Allows you to configure which hosts are allowed to query the server. If hosts are not specified, the default is to allow queries from all hosts. Query Filter can be specified in the address match list format.

Also Notify: Defines a global list of IP addresses of name servers that also receive notify messages when a fresh copy of the zone is loaded, in addition to the servers listed in the zone's NS records. This helps to ensure that the copies of the zones quickly converge on stealth servers.

Black Listed Servers: Defines the list of addresses that the server does not accept queries from or use to resolve a query. Queries from these addresses are not responded to. The default is none.

Additional-from-auth, additional-from-cache: These options control the behavior of an authoritative server when answering queries that have additional data, or when following CNAME and DNAME chains.

Allow-notify : Specifies the hosts that are allowed to notify the server about changes in a secondary zone serviced, in addition to the zone masters. If hosts are not specified, the default is to process notify messages only from a zone's master.

Cleaning-interval: Specifies the time interval, in minutes, at which the server removes expired resource records from the cache. If it is set to 0, no periodic cleaning occurs. The default value is 60 minutes.

Forward: This option can be configured only if the Forwarding list is not empty. If the value is set to first (default), the server queries the forwarders first, and if that does not answer the query, the server then looks for the answer. If the value is set to only, the server will only queries the forwarders.

Lame-ttl: Sets the number of seconds to cache a lame server indication. 0 disables caching. This is not recommended. The maximum value is 1800 (30 minutes).

Listen-on: Specifies the interfaces and ports that the server will answers queries from. It takes an optional port and an address match list. If a port is not specified, port 53 is used.

Max-cache-ttl: Sets the maximum time for which the server will caches ordinary (positive) answers.

Max-ncache-ttl: The server stores negative answers to reduce network traffic and increase performance. This option is used to set a maximum retention time for these answers in the server. The maximum value is 7 days.

Minimal-responses: If this option is set to yes, while generating responses the server will adds records to the authority and additional data sections only when they are required (for example, delegations, negative responses). This might improve the performance of the server.

Notify: If this option is set to yes, DNS notify messages are sent when a zone for which the server is authoritative for changes. The messages are sent to the servers listed in the zone’s NS records (except the master server identified in the SOA MNAME field) and to any servers listed in the also-notify option. If this option is set to explicit, notifications are sent only to servers explicitly listed by using also-notify. If this option is set to no, no notifications are sent.

Notify-source: Determines the local source address, and optionally the UDP port, that will be used to send notify messages. The slave servers should also be configured to receive notify messages from this address.

Novell_dyn-reconfig: Specifies the time interval at which dynamic reconfiguration will takes place. The minimum value is 10 minutes and the maximum is 24 hours.

Provide-ixfr : Determines whether the local server, acting as master, will respond with an incremental zone transfer when the given remote server, a slave, requests it. If this option is set to yes, incremental transfer is provided whenever possible. If this option is set to no, all transfers to the remote server are non-incremental.

Query-source: Specifies the address and port used for querying other name servers, if the server does not know the answer to a query.

Recursion: If this option is set to yes, and a DNS query requests recursion, then the server attempts to do everything required to answer the query. If this option is set to no, and the server does not already know the answer, it will returns a referral response.

Request-ixfr: Determines whether the local server, acting as a slave, will request incremental zone transfers from the given remote server, a master.

RRset-order: Permits the ordering of the records in a multiple record response to be configured. If this option is set to fixed, records are returned in a fixed order. If this option is set to random-cyclic, the server chooses a record within the RRset as the starting point and returns the records in the starting order at that point.

Serial-query-rate: Slave servers periodically query the master servers to find out if the zone serial numbers have changed. Each query uses a small amount of the slave server’s network bandwidth. You can limit the rate at which queries are sent and therefore 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 TCP client connections that the server accepts.

Transfer-format: Zone transfers can be sent by using two different formats, one-answer and many-answers. This option is used on the master server to determine the format of zone transfer. One-answer uses only one DNS message per resource record transferred and many-answers places as many resource records as possible into a message. Many-answers is more efficient.

Transfer-source: Determines the local address that is bound to the IPv4 TCP connections used to retrieve the zones transferred inbound by the server. It also determines the source IPv4 address, and optionally the UDP port, used for the refresh queries and forwarded dynamic updates.

Transfers-in: Specifies the maximum number of inbound zone transfers that can concurrently run. Increasing the transfers-in might speed up the convergence of the slave zones, but it might also increase the load on the local system.

Transfers-out: Specifies the maximum number of outbound zone transfers that can run concurrently. Zone transfer requests in excess of the limit are refused.

Transfers-per-ns: Specifies the maximum number of inbound zone transfers that can be transferred concurrently from a given remote name server. Increasing the value of this option might speed up the convergence of slave zones, but it might also increase the load on the remote name server.

Zone-statistics: Zone-statistics can be configured to yes so that the server will collects statistical data for the zones.

Zone Type: Specifies whether the zone is a primary, secondary or forward zone. If this option is set as primary, the Novell DNS servers act as primary servers for this zone. If this option is set as secondary, the servers act as secondary servers. For a forward zone, the Forward DNS server forwards queries to other name servers.

Zone Master IP Address: Specifies the IP address of the primary DNS server for the secondary zone.

Available DNS Servers: Displays all the available DNS servers that can service the zone.

Authoritative DNS Server: Displays all servers that are servicing the zone. All servers in this list are authoritative for the zone. For a primary zone, all servers listed are passive primary servers except the one specified in the Designated Primary field.

Designated Primary (for Primary Zone): Specifies the designated primary server for the zone. If you specify a server as designated primary, it is the server designated for receiving dynamic updates.

Designated Secondary (for Secondary Zone): Specifies the designated secondary server for the zone. If you specify a server as designated secondary, it is the server designated for receiving zone-in transfers.

Comments: You can type up to 256 characters of information about the name server in this field.

Forward Zone: The server forwards all requests to another DNS server and caches the results. There is no difference between a designated server and other servers.

Empty Forwarder List : An empty forwarder list is used for domain delegation (child zones). With this option, global forwarders are ignored and NS records are used for domain delegation.

Forward: Specifies the IP address to be used for forwarding. Click the Forward button, provide the IP address, then click Add.

Only : Controls the behavior of queries for which the server is not authoritative and the answers do not exist in the cache. If you specify the value as Only, the server queries only the forwarders list

First : Controls the behavior of queries for which the server is not authoritative and the answers do not exist in the cache. If you specify the value as First, the server queries the forwarders list first and, if the answer is not found, the server searches for the answer

Zone Out Filter: Specifies which hosts are authorized to do a zone out transfer for this zone from primary servers of this zone. If this field is not configured, each DNS server servicing this zone uses its own Zone Out filter list value (if configured). Otherwise, the default value is used.