Sometimes, eventhough we can browse the web, we are not able to use any chat clients/messengers like yahoo and msn. This can happen for any of the following reasons:
–> DNS Server is not working on the proxy server (service named start should fix it)
–> IPTables is restricting that port… make sure that the port is open. There should be a line like
-A POSTROUTING -o eth1 -p tcp -m tcp –dport 5050 -j MASQUERADE
in the file /etc/sysconfig/iptables in super user mode. After adding the appropriate line, restart the iptables service using ‘service iptables restart’ command.
–> Forwarding may not have been enabled. The file /proc/sys/net/ipv4/ip_forward should contain “1”. So do a
echo “1” > /proc/sys/net/ipv4/ip_forward
*collected from net