[nsp] known networks for broadcast ping attacks

It prevents the Cisco from handling packets with source routing header
options set, whether locally generated, or switched. It doesn't prevent
the router generating or switching packets with invalid source addresses
e.g. packets with source addresses from inside the network entering the
router via an external interface - you need to apply access lists to the
appropriate interfaces (in the appropriate directions) to prevent this.


All this talk of spoofing is getting me a bit confused. What

exactly is

the difference between source-routing and spoofing?

Just trying to understand a bit more,


[Rtr A] --------- | internet cloud | -----------[Rtr B]