ospg loopback config question

in CCNA & CCENT
I need some clarification. It is my understanding that no matter what the highest ip on any interface is, if a loopback ip is set, the loopback address becomes the RID. Correct? Wrong? Thanks, c__g
Thanks for the help, -cg
Comments
When a loopback (logical) IP is set, it has the highest priority over any physical interface IP. Loopback IP is used because it will never go down, so we are sure that the RID will remain up.
to set a loopback IP on a router:
Router(config)# int loopback 0
Router(config-if)#ip address <IP> <mask>
Hope this helps.
Cheers!