Hi there everyone!

I am doing a RIPv2 Lab and it says to create 3 loopback interfaces on R3 on the right, as so:
ok

... I type in the command:
R3(config)# int lo0
R3(config-if)# ip address 172.30.110.0 255.255.255.0
And what I get is that this is a:
bad mask /24 for the ip 172.30.110.0...

what the heck?!

Are loopback interfaces supporting classful subnet masks only?