I just installed 2.8/hybrid-6rc6+UniBG+services IRC server on an Linux server.(Slackware 10) I followed the setup
procedure and modified ircd.conf according to the instruction.

I also installed an mIRC32 client on Windows 2000 workstation and tried the
connection, the connection was very slow, the following messages poped up from mIRC
client:
-irc.nikem.lan- *** Looking up your hostname
-irc.nikem.lan- *** Checking Ident
-irc.nikem.lan- *** Got ident response
then hanging there for a while (1 minute), then
-irc.nikem.lan- *** Couldn't look up your hostname
then
PING? PONG!
Welcome to the Internet Relay Network....

I just wonder what's the reason the connection hanging there for so long? is that because of hostname look up, how can I skip this procedure, or at least make it faster?

And your server has all the correct DNS setup, reverse lookup.. etc? Try adding your hostname to its /etc/hosts to see if that helps speed it up as it probably isn't going to be looking what IP it has.. etc.

I have about 15 clients ?? Do I have to add them all in /etc/hosts. Also I have dns server ...
What should I do ?

Can you Linux box ping your Windows box by name? If not, setup DNS or add to /etc/hosts for faster lookups..