Hi Dear,

I am having red hat linux 6.2 with two ethernet card installed ,one for local lan and second for cable modem with 10 windows 95/98 nodes installed.

People were able send/receive email and browse on the internet with this setup.But on day the message "eth0 promiscuous mode appeared " on the screen. Because of which now i am not able to telnet the server and people can't download the meassges.

I will be grateful if somebody will help me.

Hate to tell you but if you find your machine all of a sudden with problems and your network card is in promiscuous mode there is a great chance someone has been messing with your system.
Setting a network card into promiscuous is used to be able to see all the network traffic on that subnet. Which is usefull for password sniffers. You have to have root permissions to set your network card in promiscious mode.
You might want to try and get chkrootkit to scan your system to find out if there are any bogus things on there. And read the securtiy forum to find out what to do if you really have problems.