Aggressive DNS querying from Pub, Sub, Unity
Hi, on the servers I have enabled DNS and configured R1(CorpHQ) to answer DNS queries
I am observing aggressive DNS querying (every couple of secs) by Pub, Sub, Unity
PTR record 1.10.1.177.in-addr.arpa (this is answered by R1; but the query keeps repeating)
AAAA record for slef by by Unity (why does it think it is using IPv6, is it the Linux configuration?):
When I use the SSH command line on the servers, I can ping everything using DNS names - this shows that DNS to R1 is working.
I need to either disable DNS and start again :-( or have some way to satisfy the PTR/AAAA queries.
!--- this is going on repeatedlye and flooding the network
debug domain
Aug 4 00:50:30.197: DNS: Type 12 DNS query (id#25472) for host '1.10.1.177.in-addr.arpa' from 177.1.10.30(32809)
Aug 4 00:50:30.197: DNS: Servicing request using view default
Aug 4 00:50:30.197: DNS: Finished processing query (id#25472) in 0.000 secs
Aug 4 00:50:30.197: DNS: Sending response to 177.1.10.30/32809, len 73
Aug 4 00:53:00.439: DNS: Type 28 DNS query (id#25163) for host 'unity.ine.test' from 177.1.10.30(32809)
Aug 4 00:53:00.439: DNS: Servicing request using view default
Aug 4 00:53:00.439: DNS: Reply to client 177.1.10.30/32809 query AAAA with SERVFAIL
Aug 4 00:53:00.439: DNS: Finished processing query (id#25163) in 0.000 secs
Aug 4 00:53:00.439: DNS: Sending response to 177.1.10.30/32809, len 35
Aug 4 00:53:00.443: DNS: Incoming UDP query (id#25163)
Aug 4 00:53:00.443: DNS: Type 28 DNS query (id#25163) for host 'unity.ine.test' from 177.1.10.30(32809)
Aug 4 00:53:00.443: DNS: Servicing request using view default
Aug 4 00:53:00.443: DNS: Reply to client 177.1.10.30/32809 query AAAA with SERVFAIL
Aug 4 00:53:00.443: DNS: Finished processing query (id#25163) in 0.000 secs
!---
ip dns server
no ip domain-lookup
!--- I don't want R1 to forward DNS
ip host cucmpub.ine.test 177.1.10.10
ip host cucmsub.ine.test 177.1.10.20
ip host unity.ine.test 177.1.10.30
ip host corphq.ine.test 177.1.10.1
Comments
Hi mustang7071,
Routers don't support the PTR lookups.
However, we have a Win2k8 AD DNS server setup for you on our rack rental network, just as the real lab would (if they choose to test you on DNS), so why not just use that.
You can find all of the details related to accessing that DNS server here in our Rack Rental Access Guide.