Thomas Keller:
> The only remote connections allowed are to udp port 53. Now RBAC is
> logging following error messages:
>
> postfix:U:/usr/lib/postfix/smtpd denied connect() to 74.208.4.197 port
> 0 sock type dgram protocol udp
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
