Can Missing Reverse Records Result In DNS Lookup Timeouts?

Question

I am getting DNS lookup timeouts, but all DNS health checks say that everything is fine. The only problem I found:

• At least one server is missing a reverse record pointing back to its host name

• Recursive Queries Denied

• Your SOA EXPIRE number is: 3600000. That is NOT OK

I always believed that these are optional and can be abused .. see here http://www.stupendous.net/archives/2009/01/19/annoying-dns-recursive-queries/

Answer 1

Those all look OK to me, although it would help if you told us which domain this is for.

1. Missing reverse records - nope, the DNS protocol doesn't itself rely on those for its core function
2. Recursive queries denied - yes, that's what you should have on an authoritative server
3. SOA Expire of 3600000 - 41 days, a little long maybe, but it's only used when you have masters and slaves using AXFR / IXFR, and doesn't affect normal DNS lookup timers