[squid-users] Transparent caching proxy, ASA-Squid3

From: bmm-mailinglist <squid_at_dewillem.nl>
Date: Fri, 22 Apr 2011 10:43:37 +0200

Hi all,
 
I am a new Squid user. I like Squid's ease of setup and -use. Unfortunately, I've hit a snag.
For the past week or so, I have been trying to get a transparent caching proxy going between our Cisco ASA 5510 firewall (with 8.3(2) software) and a fresh Squid 3 install on an Ubuntu 10.04 LTS (default squid3 package from Ubuntu repo).
 
So far I have been unsuccesful.
The caching proxy bit works just fine. If I manually point my browser to the Squid machine to use as a proxy, it works just as it should.
I can't get the redirect working, though. Packets redirected by the ASA just seem to get dropped somewhere along the line.
I have followed the directions stated in http://wiki.squid-cache.org/SquidFaq/InterceptionProxy#WCCP_-_Web_Cache_Coordination_Protocol. This setup did not work.
After trying anything I could think of myself (and not being an expert at this, that wasn't a whole lot), I've taken to the mailing list archives.
There, I found this thread: http://www.squid-cache.org/mail-archive/squid-users/201103/0284.html, which is similar to my situation.
I also followed the directions mentioned there, but unfortunately that did not solve my problem either.
 
In any case, the situation right now is as follows:
 
The ASA is set up for WCCP, seemingly correctly (although ASA documentation on WCCP is less than stellar).
It has recognized the Squid cache, is receiving Squid's Here I Am packets and is returning I See Yous.
According to the counter, it is also forwarding packets to Squid when I activate the rule.
 
I've set a logging rule on the prerouting table in iptables. It shows packets are coming in. So far so good.
I've also set a logging rule on the postrouting, output and forward tables, but nothing seems to be leaving the Squid machine, other than the hello packets to the ASA every 10 seconds.
Setting log_access to either allow or deny also does not create any entries in the access.log file. It seems, therefore, that the packets never reach that stage.
 
I'm kind of out of ideas at this point. Can someone point me in the right direction to start shooting at trouble again?
 
Some relevant config:
 
ASA
 
wccp web-cache redirect-list proxy group-list wccp-acl password *****
wccp interface inside web-cache redirect in

access-list proxy extended permit tcp 10.0.0.0 255.0.0.0 any eq www inactive
access-list wccp-acl extended permit ip host 10.1.7.5 any

 
Squid:
 
acl localnet src 10.0.0.0/8 # RFC1918 possible internal network
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access allow localnet
http_access allow localhost
http_access deny all
icp_access deny all
htcp_access deny all
http_port 3128 transparent
hierarchy_stoplist cgi-bin ?
cache_dir ufs /var/squid/cache 184320 16 256
access_log /var/log/squid3/access.log squid

wccp2_router 10.1.0.254
wccp2_forwarding_method 1
wccp2_return_method 1
wccp2_assignment_method 1
wccp2_service standard 0 password=squid
wccp2_address 0.0.0.0

iptables:
 
Chain PREROUTING (policy ACCEPT)
target prot opt source destination
LOG all -- anywhere anywhere LOG level warning prefix `pre'
REDIRECT tcp -- anywhere anywhere tcp dpt:www redir ports 3128
 
Chain POSTROUTING (policy ACCEPT)
target prot opt source destination
LOG all -- anywhere anywhere LOG level warning prefix `post'
MASQUERADE all -- anywhere anywhere

 
So again, any pointers would be most welcome. Should you need more config info, don't hesitate to ask.
Thanks in advance.
 
Regards,
 
Bart
Received on Fri Apr 22 2011 - 08:44:20 MDT

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