Hello All,

I'm trying to set up a transparent proxy for http and https using Cisco Routers 
and Squid.  I have followed the configuration examples that are listed under 
the wccp2 overview section (http://wiki.squid-cache.org/Features/Wccp2) of the 
squid wiki but I'm still having some issues.

I have a little lab set up with a Cisco 7200 Router and a VM with CentOS 
running the proxy.

The "WAN" IP of the Router is 192.168.0.23.  The IP of the Squid Proxy is 
192.168.0.24 and both have the default gateway of 192.168.0.1 which is the "ISP"

The Client is sitting on a LAN behind the Router in the 10.10.10.0/24 subnet 
and is also sitting behind nat.

I believe that the router and proxy are communicating properly based on the 
information in the show ip wccp command on the router as it shows clients and 
routers as well as showing that packets are being forwarded:

R3#show ip wccp
Global WCCP information:
    Router information:
        Router Identifier:                   192.168.0.23
        Configured source-interface:         GigabitEthernet5/0

    Service Identifier: web-cache
        Protocol Version:                    2.00
        Number of Service Group Clients:     1
        Number of Service Group Routers:     1
        Total Packets Redirected:            1079
          Process:                           0
          CEF:                               1079
        Service mode:                        Open
        Service Access-list:                 -none-
        Total Packets Dropped Closed:        0
        Redirect access-list:                100
        Total Packets Denied Redirect:       0
        Total Packets Unassigned:            0
        Group access-list:                   10
        Total Messages Denied to Group:      0
        Total Authentication failures:       0
        Total GRE Bypassed Packets Received: 0
          Process:                           0
          CEF:                               0
       GRE tunnel interface:                Tunnel1

    Service Identifier: 70
        Protocol Version:                    2.00
        Number of Service Group Clients:     1
        Number of Service Group Routers:     1
        Total Packets Redirected:            500
          Process:                           0
          CEF:                               500
        Service mode:                        Open
        Service Access-list:                 -none-
        Total Packets Dropped Closed:        0
        Redirect access-list:                100
        Total Packets Denied Redirect:       0
        Total Packets Unassigned:            0
        Group access-list:                   10
        Total Messages Denied to Group:      0
        Total Authentication failures:       0
        Total GRE Bypassed Packets Received: 0
          Process:                           0
          CEF:                               0
        GRE tunnel interface:                Tunnel0

Here is the relevant squid wccp configuration:

----Output removed----
# Squid normally listens to port 3128
http_port 3128
http_port 0.0.0.0:3129

# WCCPv2 Parameters
wccp2_router 192.168.0.23
wccp2_forwarding_method 1
wccp2_return_method 1
wccp2_assignment_method hash
wccp2_service standard 0
wccp2_service dynamic 70
wccp2_service_info 70 protocol=tcp 
flags=dst_ip_hash,src_ip_alt_hash,src_port_alt_hash priority=231 ports=443

---Output remove----

I think that the issue lies with the iptables configuration as I do not see any 
packets been processed in the nat table.  I have tried a few different methods 
such as:

iptables -t nat -A PREROUTING -i wccp0 -p tcp -dport 80 -j REDIRECT -to-port 
3129
iptables -t nat -A PREROUTING -i wccp0 -p tcp -dport 443 -j REDIRECT -to-port 
3129
iptables -t nat -A POSTROUTING -j MASQUERADE

or

iptables -t nat -A PREROUTING -p tcp -dport 80 -j DNAT -to-destination 
192.168.0.24:3129
iptables -t nat -A PREROUTING -p tcp -dport 443 -j DNAT -to-destination 
192.168.0.24:3129
iptables -t nat -A POSTROUTING -j MASQUERADE

I have also tried adding ACCEPT commands to the PREROUTING zone just in case 
the proxy is dropping the packets right away but that also doesn't work.

The proxy functions perfectly when the client is configured to use a proxy so 
there doesn't appear to be any issues with routing or anything like that, it's 
just the transparent proxying that isn't working.

If anyone has any suggestions of what I could try that would be greatly 
appreciated.  Let me know if anything is unclear or if you need further 
clarification.

Thank you,
Cooper Waldon


Cooper Waldon l Network Engineer l OTN l 416-446-4110 x 4473 l 
www.otn.ca<http://www.otn.ca/> | Service Desk 1-855-654-0888 x2

_______________________________________________
squid-users mailing list
squid-users@lists.squid-cache.org
http://lists.squid-cache.org/listinfo/squid-users

Reply via email to