On 6/10/20 6:01 PM, Baldur Norddahl wrote:
Am I correct in assuming loose mode RPF only drops packets from unannounced address space in the global routing table? And the downside of doing so is that sometimes we do receive packets from that address space, usually back scatter from traceroute or other ICMP messages.
Currently about 25% of the routable address space is not advertised in the DFZ. Loose mode RPF could filter this. Is there any data on how much traffic actually arrives from this space?
Loose mode RPF will essentially drop traffic received on the interface if the router does not have any route for. (will not match a default or a discard route, at least in IOS-XR) As Bill has pointed out, this may drop traffic from some peering networks that are not in the global routing table. Though one could argue that if a packet needs to be fragged it's typically closer to the edges rather than the transit/peering links. -- inoc.net!rblayzor XMPP: rblayzor.AT.inoc.net PGP: https://pgp.inoc.net/rblayzor/