changing IP on sql server linked server I have a remote linked server that got moved to a different IP address.
After dropping the server with sp_dropserver and add it with new URL with sp_addlinkedservers, will I have to add everything back again (username, password, etc.)? 
Does sp_dropserver destroy the associated data ? Or that data is linked to the ID and kept? The server and respective SW is the same, only IP changes.
Yes, if you've dropped the linked server then you'll need to setup everything again from scratch.  You could script it out first, all you'll need to do then is change the IP address and password in the script and run it back in again.