Which statement is correct in this scenario?

You want to use IS-IS on a GRE interface where the underlying Layer 3 MTU is 1500.

Which statement is correct in this scenario?
A . IS-IS can be used because every IS-IS interface must be capable of transmitting packets at least as large as 1476 bytes, and the GRE header is 24 bytes.
B . IS IS can be used, but the networking device directly attached to the circuit must be capable of fragmentation.
C . IS-IS cannot be used, but the router can enable a GRE key that serves the same function as IS-I
E . IS-IS cannot be used because the IS-IS hello is not allowed to be fragmented and has the DF bit set.

View Answer

Answer: B