Order of Operations for DNS on the Switch
You can configure up to six DNS servers and up to six DNS suffixes. When you use a name instead of an IP address in a command, the Avaya Multiservice switch will first check to see if the name is a fully qualified domain name (ex: hostA.avaya.com). If it is, this will be sent to the first DNS server in the list of servers.
If it is not a fully qualified domain name (ex: just hostA) and a suffix(es) has been specified, the first suffix will be appended to the name; and then sent to the DNS server. If no suffix(es) is configured, it will be sent as is for resolution.
If the server cannot resolve the name, the Avaya Multiservice switch will use the same method with the second configured suffix. Once it has exhausted the configured DNS suffixes, it will attempt the query with the second DNS server.
This process will continue until the name is either resolved, there are no more DNS servers in the list, or the DNS server returns an error. Table�61 lists the error messages and their meanings that you may encounter when using the DNS client.
Table�61:�DNS Error Codes �
| Error Message |
Explanation |
| Bad ARGS |
indicates that DNS is Disabled but the user entered a host name. |
| Name Too Long |
the name sent is too long. RFC 1034 limits DNS names to 255 characters.
|
| Bad Name |
indicates that the name was in some way invalid
|
| Label Too Long |
indicates that the label of a DNS name was too long. RFC 1034 limits labels to 63 octets. |
| Time-out |
indicates that the DNS query has expired. This implies that the query could not be answered at the present time. |
| Server Failure |
indicates that the DNS server is unable to answer due to a failure on the DNS server itself. |
| Non-Existent Name |
indicates that the DNS server authoritatively claims that the DNS name does not exist. |
| NIY |
Indicates the DNS server does not support the requested service. You may have specified the correct DNS server but the server has not yet been configured to respond to DNS queries. |
| Refused |
indicates that the DNS server refuses to answer the query for administrative reasons. Possibly due to security implementations on the DNS server. |
| No RRs |
indicates that the DNS server authoritatively claims that there are no RRs that match the specified name, type and/or class. |
| No Recursion |
indicates that one of the configured DNS servers does not support Recursion. |
| Irrelevant |
indicates that a response message was received that does not match the query sent. |
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