RE: [squid-users] Updated CentOS/Squid/Tproxy Transparency steps.

On Wed, 1 Jul 2009 16:59:03 -0700, "Alexandre DeAraujo" <alexd_at_cal.net>
wrote:
> I am giving this one more try, but have been unsuccessful. Any help is
> always greatly appreciated.

I've had the opportunity to work through at a very low level with someone
recently and found the major issue with WCCP and TPROXY. It seems the
claimed auto-detection and bypass of proxy outbound traffic depends on IP
address in the outbound packet (under TPROXYv4 this is the wrong address).
Check that you can identify the outbound proxy traffic using something
other than the IP and add a bypass rule manually. Good things to test for
are source interface (ethX, MAC, EUI-64), or apparently service group.
Maybe TOS as well if you also have Squid set that.

The Features/Tproxy4 wiki page is updated with this and some details on
what to look for and some other general options that may solve it.

Amos

>
> Here is the setup:
> Router:
> Cisco 7200 IOS 12.4(25)
> ip wccp web-cache redirect-list 11
> access-list 11 permits only selective ip addresses to use wccp
>
> Wan interface (Serial)
> ip wccp web-cache redirect out
>
> Global WCCP information:
> Router information:
> Router Identifier: 192.168.20.1
> Protocol Version: 2.0
>
> Service Identifier: web-cache
> Number of Service Group Clients: 1
> Number of Service Group Routers: 1
> Total Packets s/w Redirected: 8797
> Process: 4723
> Fast: 0
> CEF: 4074
> Redirect access-list: 11
> Total Packets Denied Redirect: 124925546
> Total Packets Unassigned: 924514
> Group access-list: -none-
> Total Messages Denied to Group: 0
> Total Authentication failures: 0
> Total Bypassed Packets Received: 0
>
> WCCP Client information:
> WCCP Client ID: 192.168.20.2
> Protocol Version: 2.0
> State: Usable
> Initial Hash Info: 00000000000000000000000000000000
> 00000000000000000000000000000000
> Assigned Hash Info: FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
> FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
> Hash Allotment: 256 (100.00%)
> Packets s/w Redirected: 306
> Connect Time: 00:21:33
> Bypassed Packets
> Process: 0
> Fast: 0
> CEF: 0
> Errors: 0
>
> Clients are on FEthernet0/1
> Squid server is the only device on FEthernet0/3
> --------------------------------------------------------------------
> Squid Server:
> eth0 Link encap:Ethernet HWaddr 00:14:22:21:A1:7D
> inet addr:192.168.20.2 Bcast:192.168.20.7
Mask:255.255.255.248
> inet6 addr: fe80::214:22ff:fe21:a17d/64 Scope:Link
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> RX packets:3325 errors:0 dropped:0 overruns:0 frame:0
> TX packets:2606 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:335149 (327.2 KiB) TX bytes:394943 (385.6 KiB)
>
> gre0 Link encap:UNSPEC HWaddr
> 00-00-00-00-CB-BF-F4-FF-00-00-00-00-00-00-00-00
> inet addr:192.168.20.2 Mask:255.255.255.248
> UP RUNNING NOARP MTU:1476 Metric:1
> RX packets:400 errors:0 dropped:0 overruns:0 frame:0
> TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:0
> RX bytes:31760 (31.0 KiB) TX bytes:0 (0.0 b)
> --------------------------------------------------------------------
> /etc/rc.d/rc.local file:
> ip rule add fwmark 1 lookup 100
> ip route add local 0.0.0.0/0 dev lo table 100
> modprobe ip_gre
> ifconfig gre0 192.168.20.2 netmask 255.255.255.248 up
> echo 1 > /proc/sys/net/ipv4/ip_nonlocal_bind
> --------------------------------------------------------------------
> /etc/sysconfig/iptables file:
> # Generated by iptables-save v1.4.4 on Wed Jul 1 03:32:55 2009
> *mangle
> :PREROUTING ACCEPT [166:11172]
> :INPUT ACCEPT [164:8718]
> :FORWARD ACCEPT [0:0]
> :OUTPUT ACCEPT [130:12272]
> :POSTROUTING ACCEPT [130:12272]
> :DIVERT - [0:0]
> -A DIVERT -j MARK --set-xmark 0x1/0xffffffff
> -A DIVERT -j ACCEPT
> -A PREROUTING -p tcp -m socket -j DIVERT
> -A PREROUTING -p tcp -m tcp --dport 80 -j TPROXY --on-port 3128 --on-ip
> 192.168.20.2 --tproxy-mark 0x1/0x1
> COMMIT
> # Completed on Wed Jul 1 03:32:55 2009
> # Generated by iptables-save v1.4.4 on Wed Jul 1 03:32:55 2009
> *filter
> :INPUT ACCEPT [0:0]
> :FORWARD ACCEPT [0:0]
> :OUTPUT ACCEPT [160:15168]
> :RH-Firewall-1-INPUT - [0:0]
> -A INPUT -i gre0 -j ACCEPT
> -A INPUT -p gre -j ACCEPT
> -A INPUT -i eth0 -p gre -j ACCEPT
> -A INPUT -j RH-Firewall-1-INPUT
> -A FORWARD -j RH-Firewall-1-INPUT
> -A RH-Firewall-1-INPUT -s 192.168.20.1/32 -p udp -m udp --dport 2048 -j
> ACCEPT
> -A RH-Firewall-1-INPUT -i lo -j ACCEPT
> -A RH-Firewall-1-INPUT -p icmp -m icmp --icmp-type any -j ACCEPT
> -A RH-Firewall-1-INPUT -p esp -j ACCEPT
> -A RH-Firewall-1-INPUT -p ah -j ACCEPT
> -A RH-Firewall-1-INPUT -d 224.0.0.251/32 -p udp -m udp --dport 5353 -j
> ACCEPT
> -A RH-Firewall-1-INPUT -p udp -m udp --dport 631 -j ACCEPT
> -A RH-Firewall-1-INPUT -p tcp -m tcp --dport 631 -j ACCEPT
> -A RH-Firewall-1-INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
> -A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j
> ACCEPT
> -A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
> COMMIT
> # Completed on Wed Jul 1 03:32:55 2009
>
> ---------------------squid.conf------------------------------------
> acl manager proto cache_object
> acl localhost src 127.0.0.1/32
> acl to_localhost dst 127.0.0.0/8
> acl localnet src 10.0.0.0/8 # RFC1918 possible internal network
> acl localnet src 172.16.0.0/12 # RFC1918 possible internal network
> acl localnet src 192.168.0.0/16 # RFC1918 possible internal network
> acl testing src 10.10.10.0/24
> acl SSL_ports port 443
> acl SSL_ports port 8443
> acl Safe_ports port 80 # http
> acl Safe_ports port 21 # ftp
> acl Safe_ports port 443 # https
> acl Safe_ports port 70 # gopher
> acl Safe_ports port 210 # wais
> acl Safe_ports port 1025-65535 # unregistered ports
> acl Safe_ports port 280 # http-mgmt
> acl Safe_ports port 488 # gss-http
> acl Safe_ports port 591 # filemaker
> acl Safe_ports port 777 # multiling http
> acl Safe_ports port 8443 # Plesk
> acl CONNECT method CONNECT
> http_access allow manager localhost
> http_access allow testing
> http_access deny manager
> http_access deny !Safe_ports
> http_access deny CONNECT !SSL_ports
> http_access allow localnet
> http_access deny all
> http_port 192.168.20.2:3128 tproxy disable-pmtu-discovery=always
> hierarchy_stoplist cgi-bin ?
> hosts_file /etc/hosts
> refresh_pattern ^ftp: 1440 20% 10080
> refresh_pattern ^gopher: 1440 0% 1440
> refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
> refresh_pattern . 0 20% 4320
> coredump_dir /var/spool/squid
>
> logformat squid %ts.%03tu %6tr %>a %Ss/%03Hs %<st %rm %ru %un %Sh/%<A %mt
> access_log /var/log/squid/access.log squid
> cache_access_log /var/log/squid/access.log
> cache_log /var/log/squid/cache.log
> cache_store_log /var/log/squid/store.log
> debug_options ALL,3
>
> cache allow testing
> cache deny all
> cache_dir ufs /var/spool/squid 200000 256 256
> cache_effective_user squid
> cache_swap_high 100%
> cache_swap_low 80%
> cache_mem 2 GB
> maximum_object_size 8192 KB
> half_closed_clients on
> client_db off
>
> wccp2_router 192.168.20.1
> wccp_version 2
> wccp2_rebuild_wait on
> wccp2_forwarding_method 1
> wccp2_return_method 1
> wccp2_assignment_method 1
> wccp2_service standard 0
>
> visible_hostname Server
>
> forwarded_for off
> ---------------------------------end of
> squid.conf-------------------------------------
> This is the timeout error when trying to go to www.google.com
>
> ERROR
> The requested URL could not be retrieved
>
> The following error was encountered while trying to retrieve the URL:
> http://www.google.com/
>
> Connection to 74.125.45.100 failed.
>
> The system returned: (110) Connection timed out
>
> The remote host or network may be down. Please try the request again.
>
> Generated Wed, 01 Jul 2009 21:41:07 GMT by Server (squid/3.1.0.9)
>
>
> Thanks for your help,
>
> Alex
Received on Thu Jul 02 2009 - 01:04:23 MDT