Hello


I want to find IP addresses of msn, yahoo, skype, ... servers messengers for marking, priortization than their connections.

Please, help me to find the IPs (range) for most messengers.

Thank you in advance.

there is no specific IP address, because they don't use servers. Users connect to each other instead.

Use Layer7 packet marking to find these programs. See Wiki for examples

Windows messenger has specific ports and servers (but if you use file transfer or voice service it will uses p2p connections).
I think it is the same with yahoo.

For skype try to use L7 filter or, if your custumers use specific devices like skype-phone in their lan, mark traffic from src-address.