Hi there, I'm new to IRC and have a question:

When you do a /WHOIS, why do some IP addresses come up with the full address and the domain name, while others come up with random numbers and letters ending in .IP?

Thank you

This is dependent on settings on the network and your level of access on the network.
If you have IRCops access on the network, odds are you will be able to see both styles that are returned.

Basically, the network is hiding the actual IP address from people that don't have IRCops access.

Ok, would there be a way to change the network settings on my router or modem to display the random numbers and letters when I am on IRC?

Thanks

No.

What you are refering to are two situations:

1. People who have a reverse DNS entry for their IP address *and* whose DNS for that domain matches the original IP address, receive a partially masked host where the first part of the domain name separated by a period/full stop is masked/hidden.

2. People who do not have a reverse DNS entry *or* whose DNS does not match the original IP address have a masked/hidden IP address as their host when you /whois them. IP address masks are (almost) always fully hidden.

Since your ISP determines whether you have a reverse DNS entry and whether your reverse DNS matches your DNS, there is nothing you can do about this.