> > Separarate redirect routes into two categories:
> > 	(a) - routes which have been used to send a packet
> > 	(b) - routes which have not been used.
> > 
> > if set (b) is non-empty, pick a member at random and delete it.
> > otherwise, pick a member of (a) at random and delete it.
> 
> Why would (b) exist except for packets to have been routed with it?

the redirect/path mtu route could have been created as a result of a
forged icmp message (part of a denial-of-service attack).

					- Bill