On 2015-08-23 15:40, Wietse Venema wrote: > > The resolver(3) system library uses connected UDP sockets. Other > system library functions introduce their own system calls. Even if > you think you have discovered all "normal" behavior, you can expect > random failures, because the normal behavior does not cover all > unusual scenarios. For example, Viktor already mentioned the need > for DNS over TCP when a response is too large for UDP. > > Wietse >
thanks to both for the help. I have enabled tcp port 53 as well, but I still get the same errors. I have noticed that I only get this error, when the hostname resolves to multiple IP addresses, as in $ host 74.208.4.197 197.4.208.74.in-addr.arpa domain name pointer mout.perfora.net. $ host mout.perfora.net mout.perfora.net has address 74.208.4.195 mout.perfora.net has address 74.208.4.196 mout.perfora.net has address 74.208.4.197 mout.perfora.net has address 74.208.4.194 I then get the errors for all IPs listed I understand that this is done by the resolver library and not Postfix. But since we are already talking here about this, can you perhaps see what is happening ? Is it possible resolve is trying to ping the IPs? thanks, Thomas
