Mirc

[human1987]

Hmm... do you people log on to MIRC? I just wanna ask something over here
How do i change the ip that is stated behind the @
Eg: asd@

[reboot]

You don't (usually).
That is YOUR IP as assigned by your ISP.
Some cable and dsl networks assign that IP based on the MAC address of the network card. Change the card, change the IP, but not all work that way.
Some routers allow you to manually change the MAC, which would assign a new IP.
Some IRC networks allow you to have a virtual host (vhost), which let's you put anything you want after the @ symbol.
Depending on network, you must have a registered nickname, and ask one of the network ops (not a channel op), about vhost.
FYI, one does not "log on to mirc". One uses mirc (an IRC client/app) to log on to an IRC network. There are well over 100 public networks.
Why do you want to change your IP?

[human1987]

Hmm.. i wanted my IP to appear different from others. It should be virtual host which i am talking about. How do i set up virtual host then? I hope this is legal as i saw many with different vhost.

[glc]

Again, that's dependent on the particular IRC network. You need to visit the help channel on the particular net (or perhaps look at their website?) to get details.

[human1987]

Oh okay. so where do i dl the "program" for vhost? or any other things to set up vhost?

[AerynSedai]

i haven't done anything with irc for a long, long, long time. but as i remember, the protocol requires a NICK and USER command before it will register you and send you the MOTD. it is in the USER command that you can set your username, hostname, servername, and realname. hostnames and servername are usually ignored as the irc server itself will perform a simple reverse DNS lookup based on your IP (that means it queries those magical DNS servers to get your hostname). usernames are usually verified through use of a separate identity server.

this is the original specification. i've been around the internet much longer than most. things might have changed since then. i wouldn't be surprised either; the original spec was rather insecure.

but, my guess is still that your hostname is determined through a reverse DNS lookup. nothing you can do about that really, especially if you have no control over your hostname (like a public isp).

AS

[glc]

Some of the IRC networks offer hostmasking - that's why you have to inquire at the specific net. To run your own true Vhost, you would probably have to be running a Linux/Unix client out of a shell.

On Undernet, where we have the #pcmech channel, they offer hostmasking as part of user registration. Instead of being glc@user-xxxxxxx.dsl.mindspring.com, I'm glc@glc.users.undernet.org when I log in and authenticate, and another user cannot get my IP address - a /dns on my nick will return an error message.

[reboot]

It would help if we knew which irc network you are logging in to. Then we could specify how (if possible) to get a vhost/hostmask assigned.
Usually, one must have a registered nickname, then you must log in and identify, and then request a vhost.

[human1987]

irc network: irc.galaxynet.org

[reboot]

When you log on, go to #GalaxyHelp
That's the official question and answer channel for that network.
They have a nickserv so you can register a nickname, but no hostserv.
Log on and type: /msg NS help