ISIS: Jumbo Frames enabling causes high CPU Load !

Back in this post we mentioned how changing mtu causes ISIS neighborship to go down.
This was remedied by have the same clns mtu on both peers.

However this might cause another problem.
Every 10secs hello are sent out to neighbors with frames of size of the clns mtu.
This is done by padding data onto the frames.
This is called hello padding.

To optimize CPU cycles we can disable Hello Padding.

Either using router level cmd or Interface level cmd
router isis
no hello padding multi-point

OR

int s2/0.1 multipoint
no isis hello padding

Also configure the peer

int s2/0
no isis hello padding