Hi pals,
I have configured Squid 2.6 in RHEL 5.2. It works fine will all http & https requests. The only problem what i am facing is all the clients are not able to login to Yahoo messenger even after flushing the iptables and SELinux disabled. Here is my squid conf. Pls help me to sort out this. I tried many of the possible ways...

acl all src 0.0.0.0/0.0.0.0
acl manager proto cache_object
acl localhost src 127.0.0.1/255.255.255.255
acl to_localhost dst 127.0.0.0/8
acl SSL_ports port 443
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 5050 # yahoo messenger
acl Safe_ports port 5100 # yahoo webcam
acl Safe_ports port 2047 # Yahoo webcam
acl Safe_ports port 2048 # Yahoo webcam
acl CONNECT method CONNECT

http_access allow manager localhost
http_access deny manager

http_access deny !Safe_ports

http_access deny CONNECT !SSL_ports
http_access deny to_localhost

acl our_networks src 192.168.1.0/24 192.168.2.0/24
http_access allow our_networks
# And finally deny all other access to this proxy
http_access allow localhost
http_access deny all

You need to enable access logging so that you can see what is happening.

Also, use this information as a guide for what you need to allow.

Here is the output of my log file....

1228294494.188 1172 192.168.1.21 TCP_MISS/200 590 GET http://insider.msg.yahoo.com/ycontent/? - DIRECT/209.191.120.30 text/xml
1228294501.681 1128 192.168.1.21 TCP_MISS/200 712 GET http://insider.msg.yahoo.com/ycontent/? - DIRECT/209.191.120.30 text/xml
1228294501.762 1222 192.168.1.21 TCP_MISS/200 590 GET http://insider.msg.yahoo.com/ycontent/? - DIRECT/68.180.219.51 text/xml

Now the messenger is working like on and off..Its not stable...

AFAICT that doesn't show anything being blocked.