[squid-users] Always getting TCP connection failed in cache.log

[Akmal Abbasov]

Hi, 
I have a squid 3.3, which has 1 parent, no siblings.
The cache.log file is full of
2015/09/09 10:13:08| TCP connection to parent1.net/443 failed
2015/09/09 10:13:12| TCP connection to parent1.net/443 failed
2015/09/09 10:13:13| TCP connection to parent1.net/443 failed
2015/09/09 10:13:15| TCP connection to parent1.net/443 failed
2015/09/09 10:13:15| Detected DEAD Parent: Parent1
2015/09/09 10:13:16| Detected REVIVED Parent: Parent1
2015/09/09 10:13:37| TCP connection to parent1.net/443 failed
2015/09/09 10:13:38| TCP connection to parent1.net/443 failed
2015/09/09 10:13:40| TCP connection to parent1.net/443 failed
2015/09/09 10:13:49| TCP connection to parent1.net/443 failed
2015/09/09 10:13:53| TCP connection to parent1.net/443 failed
2015/09/09 10:13:58| TCP connection to parent1.net/443 failed
2015/09/09 10:14:10| TCP connection to parent1.net/443 failed
2015/09/09 10:14:14| TCP connection to parent1.net/443 failed
2015/09/09 10:14:16| TCP connection to parent1.net/443 failed
2015/09/09 10:14:16| TCP connection to parent1.net/443 failed
2015/09/09 10:14:16| Detected DEAD Parent: Parent1
2015/09/09 10:14:19| Detected REVIVED Parent: Parent1
2015/09/09 10:14:46| TCP connection to parent1.net/443 failed
2015/09/09 10:14:46| Error sending to ICMPv6 packet to []. ERR: (101) Network is unreachable
2015/09/09 10:14:49| TCP connection to parent1.net/443 failed
2015/09/09 10:14:55| TCP connection to parent1.net/443 failed
2015/09/09 10:14:57| TCP connection to parent1.net/443 failed
2015/09/09 10:14:59| TCP connection to parent1.net/443 failed
2015/09/09 10:15:01| TCP connection to parent1.net/443 failed
2015/09/09 10:15:16| TCP connection to parent1.net/443 failed
2015/09/09 10:15:17| TCP connection to parent1.net/443 failed
2015/09/09 10:15:20| TCP connection to parent1.net/443 failed
2015/09/09 10:15:29| TCP connection to parent1.net/443 failed
2015/09/09 10:15:29| Detected DEAD Parent: Parent1

The cache_peer is configured as follows 
cache_peer parent1.net parent 443 0 no-query no-digest originserver ssl ssloptions=NO_SSLv3 name=Parent1

One more thing, 
There are TCP_MISS/500 in access.log at the exact same time as 2015/09/09 10:14:19| Detected REVIVED Parent: Parent1 messages in cache.log.

I would appreciate any suggestions.

Thanks.