06-18-2008 03:56 PM - edited 03-11-2019 06:01 AM
Hello,
I am getting following critical log message:
DENY INBOUND UDP from X.Y.Z.1/53 to P.Q.R.2/1025 due to DNS response
No impact on client/server side though. But this is continuosly generating log.Related ACL are allowed for DNS response.
what is causing this message to log.Please advise.
regards
SAS
06-18-2008 06:58 PM
Can you please post the complete log line? Also including the Log number.
Regards
Farrukh
06-18-2008 08:05 PM
Hi,
The number of message is 106007.
Explanation : This is a connection-related message. This message is displayed if a UDP packet containing a DNS query or response is denied.
Recommended Action : If the inside port number is 53, the inside host probably is set up as a caching name server. Add an access-list command statement to permit traffic on UDP port 53, and a translation entry for the inside host. If the outside port number is 53, a DNS server was probably too slow to respond, and the query was answered by another server.
Reference: http://www.cisco.com/en/US/docs/security/asa/asa72/system/message/logmsgs.html#wp1279764
I hope this helps.
Best regards.
Massimiliano.
06-19-2008 11:13 AM
thanks for the reply, In fact I had referred to this link and tried allowing required policies but same problem persists... any advices further.
regards
SAS
11-10-2008 10:09 AM
Hi,
I'm working on the same issue and what I get it that one DNS server has responded and the firewall DNS inspection engine realizes this so it doesn't respond to the DNS query. I don't think its a harmful log message but I'm looking into it further on my end.
Craig
11-10-2008 10:33 PM
Yes this message is normal if you have two servers configured for DHCP relay in the firewall. The first DNS response is allowed through but the second is blocked (and rightly so).
Regards
Farrukh
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide