[squid-users] [External] Re: Need help

[Amos Jeffries]

On 17/11/17 02:08, Vayalpadu, Vedavyas wrote:
> Hello uhlar,
> 
> No , I am bit new to squid proxy server, we have taken a TCP dump from the system and we see that.
> 
> 1. From external application to proxy server the traffic is flowing, but from Proxy server to the internal application server traffic is not flowing.
> 2. But from Proxy server to the internal application, trace route and telnet is happening.
> 

That log entry means that Squid was not able to locate any server IP 
addresses that will work for that transaction.

Either DNS has no results, client original dst-IP is not available, or 
the servers Squid does find are a) forbidden for use or b) currently 
DOWN according to the dynamic availability checks (ICMP echo, ICP query 
for cache_peer, and past TCP connection attempts).

The cache.log lines immediately following the one you quoted tell the 
results from DNS and each of those access controls so you can see what 
the reason for the failure was.

Amos