Thus spake <bdragon@gweep.net>
<snip>
our packets. While I'm certainly in favor of anything edge providers can do to eliminate denial of service attacks based on source-routing, I certainly don't want anything further. <snip>
denial of service based upon source routing? I hadn't heard of any denial of service attacks of that sort.
Disabling source-routing is like filtering icmp, sure you might block a few abuses, but more often than not, you are throwing out legitimate traffic.
I can't come up with any legitimate reason to use source-routed packets today. If your routers even support them, they probably consume orders of magnitude more processing power than normal packets; that is enough reason to disable source-routing, not to mention the security implications.
S
Validation of routing policy to ensure others aren't abusing you (pointing default, for example). As for orders of magnitude, once an IP option is in a packet, the damage is essentially done, otherwise looking up the path to an address in the options is no more impactive than looking up the address in the original destination field. source-routing only has security implications to those with defenses which permit traffic through some type of backdoor. The backdoor has more security implications than the source-routing, since it may be compromised in other manners.