1 GSLB error handling for unsupported DNS requests
Error handling response format
The GSLB error handling response format complies with RFC 2308, NODATA type 3 response. By default, the return code (rcode) is noerror. The RFC 2308 format is as follows.
NO DATA RESPONSE: TYPE 3 Header:
RDCODE=NOERROR
Query:
ANOTHER.EXAMPLE.A
Answer:
<empty>
Authority:
<empty>
Additional:
<empty>
The above is an authoritative answer with rcode=NOERROR, answer=0, and no Start of Authority (SOA) record. This error handling response prevents the client from timing out on the query and causes the client to query for another record type instead of continuing to query for the unsupported record type.
Although Brocade does not advise you to do so, you can configure the return code for error handling responses. Refer to the section “Configuring the return code” on page 190.
Disable or re-enabling GSLB error handling
GSLB error handling is enabled by default in cache proxy configurations. It is disabled by default in transparent intercept mode.
To disable GSLB error handling, enter the following command.
Syntax: [no] gslb no-error-handling
To
Configuring the return code
Although Brocade does not advise you to do so, you can configure the return code for error handling responses, by entering a command such as the following:
This option causes the GSLB ServerIron ADX to respond with the error code notimp (not implemented) in the error handling response.
Syntax: [no] gslb
former = format error
noerror = no error (the default) notimp = not implemented nxdomain =
190 | ServerIron ADX Global Server Load Balancing Guide |
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