The default policy on an ASA firewall is to drop DNS UDP datagrams larger than 512 bytes. Have you modified this policy? We had quite some DNS root-servers sending UDP packets of 541 bytes. Is there som general recommendation?
I know this is an old post and my question relates to IOS Firewall. How do you change the DNS UPD packet size on an IOS firewall?
I know how to do this on a PIX, but not on the IOS firewall.
Thanks.
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