As discussed in Question 1.26, Kerberos tickets contain the IP addresses of
hosts they are to be used on.

In addition to forwardable tickets, Kerberos 5 introduce the concept of
proxiable tickets. A proxiable ticket is a ticket (generally only a TGT)
that allows you to get a ticket for a service with IP addresses other than
the ones in the TGT.

This is different than forwardable tickets in that you cannot proxy a new
TGT from your current TGT; you can only proxy non-TGT service tickets. In
other words, forwardable tickets let you transfer your complete identity
(TGT) to another machine, where proxy tickets only let you transfer
particular tickets.

In general practice, proxiable tickets are not used that often.