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/
