The every day things from Thalamus' life.

Thalamus' Blog

10 February, 2012

Fixing “unexpected RCODE (SERVFAIL)” and “unexpected RCODE (REFUSED)”

Filed under: ComputerStuff_en — Thalamus @ 13:52

I run my own named and dhcpd in my own network. I’ve choosen googles public servers as the resolvers/forwarders. I kept getting the above message in my /var/log/messages file. The solution is that the MTU is too high and this makes the local named spew out these. I could have lowered the MTU on the interface towards internet. But, instead I put up OpenDNS as the first forward host and kept one of the googles as a backup.

To check if you have the same problem – you can pr. example try to ping the server with packets in the length of 1500. ( $ ping -s 1500 ) If it fails, and normal ping does work. Well, then you are effected as well. Lower the MTU or change public DNS server.

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