Alts do not have different IP to mains, whether an account is an alt or not has nothing to do with IP.

IP is denoted by the router it is logged in through.

For the reasons I explained above you should not be able to see any IP in the login including your own. They should instead be indicated in an arbitrary fashion such as the one described in the OP.

The system you described Fates - I cant see any reason for, you can only see the times you logged in through the router you usually use? Why? It doesnt show you failed attempts and hacking or a successful attempt. I.E. it doesnt make hacking detection any easier for the user which is what Ive set out to do here.