can't contact servers

Vernon Schryver
Mon Aug 2 21:52:13 UTC 2004

> From: Michael Grant 

> But here's the output of a cddc RTT command with debug turned on.
> Notice the 'Connection refused'?  That seems like cdcc isn't able to
> bind to the udp socket.  What could cause this?  I am running cdcc as
> root.  I have tried with both root and the non-root dcc user in the
> conf file, same thing.

Some operating systems report ICMP error messages including
Unreachables received for a bound UDP socket as as ECONNREFUSED.
Never mind that they usually have ENETUNREACH and EHOSTUNREACH
defined in /usr/include/sys/errno.h

My guesses are that:

 1. you have a firewall that is blocking outgoing UDP to port 6277
   and answering with ICMP Unreachables.  That firewall could be a
   separate box or ipchains/ipfw/etc.

 2. you have routing problems your host or some router in the path
  is answering with Unreachables.  A lost default route is a good way
  to cause such problems.

I would start debugging the problem with net snooping.  If tcpdump
is available, I'd try `tcpdump -nls 1500 port 6277` first on the the
host running `cdcc rtt` in another shell and then at various points
on the path to the Internet.

> # skipping asking Greylist server 8 seconds more
>,-                 Greylist 32768 2237057701x1509
> #,-
> #      not answering

Are you using greylisting?  If not, then that stuff from `cdcc rtt`
is irrelevant.  If you are, then what is happening with your local
dccd for greylisting?

Vernon Schryver

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