Current recipe for anti-forging with Cisco hardware:
o Pick up CEF code (11.1(17)CC, which doesn't yet (?) exist for all
Cisco platforms, unfortunately)
o Configure:
!
ip cef switch
! or "ip cef distributed switch" for an RSP+VIP2 based box
!
interface whatever
ip verify unicast reverse-path
!
I don't know what exact configs are vulnerable, but don't try this
on a 7206 if you have a PA-8T with frame relay on it.
I had CEF only on PA-2T3 ports and F0/0 on the controller card and yet
all frame relay connections on multiple T1s on the PA-8T were trashed.
cscdj87169 is not resolved yet.