Nuts and Bolts
Encapsulation
- IS-IS runs directly over L2 (next to IP)
- Sort of makes sense, architecturally
- Partition repair requires tunneling (rarely implemented)
- More difficult to spoof or attack
- More difficult to implement in some environments
- Requires ATM SNAP encapsulation, forcing two-cell TCP acks (but Henk SmitÅfs NLPID hack fixes this)