nanog mailing list archives
Re: Is it time to abandon bogon prefix filters?
From: Chris Adams <cmadams () hiwaay net>
Date: Mon, 18 Aug 2008 09:29:52 -0500
Once upon a time, Sam Stickland <sam_mailinglists () spacething org> said:
I think you misunderstand the meaning of the "ip verify unicasr source reachable-via any" command. When a packet arrives the router will drop it if it doesn't have a valid return path for the source. Since the source is a bogon, and routed to Null0, then the inbound packet is dropped.
First, that is only true on Cisco routers (all the world is not a Cisco). Second, you are missing the point: you have bogon route for 10/8, but rouge route for 10.1/16 (or even 10.0/9 and 10.128/9) arrives; it is more specific and your automatic bogon filter is useless. -- Chris Adams <cmadams () hiwaay net> Systems and Network Administrator - HiWAAY Internet Services I don't speak for anybody but myself - that's enough trouble.
Current thread:
- Re: Is it time to abandon bogon prefix filters?, (continued)
- Re: Is it time to abandon bogon prefix filters? Laurence F. Sheldon, Jr. (Aug 15)
- Re: Is it time to abandon bogon prefix filters? Robert E. Seastrom (Aug 15)
- RE: Is it time to abandon bogon prefix filters? Tomas L. Byrnes (Aug 16)
- Re: Is it time to abandon bogon prefix filters? Pete Templin (Aug 17)
- RE: Is it time to abandon bogon prefix filters? Tomas L. Byrnes (Aug 17)
- RE: Is it time to abandon bogon prefix filters? michael.dillon (Aug 18)
- Re: Is it time to abandon bogon prefix filters? Jared Mauch (Aug 18)
- Re: Is it time to abandon bogon prefix filters? Pete Templin (Aug 18)
- Re: Is it time to abandon bogon prefix filters? Sam Stickland (Aug 18)
- Re: Is it time to abandon bogon prefix filters? Nathan Ward (Aug 18)
- Re: Is it time to abandon bogon prefix filters? Chris Adams (Aug 18)
- RE: Is it time to abandon bogon prefix filters? Tomas L. Byrnes (Aug 18)
- Re: Is it time to abandon bogon prefix filters? Danny McPherson (Aug 18)
- Re: Is it time to abandon bogon prefix filters? Sean Donelan (Aug 21)
- RE: Is it time to abandon bogon prefix filters? Tomas L. Byrnes (Aug 24)
- Re: Is it time to abandon bogon prefix filters? Valdis . Kletnieks (Aug 25)
- Re: Is it time to abandon bogon prefix filters? Chris Marlatt (Aug 25)
- Re: Is it time to abandon bogon prefix filters? Valdis . Kletnieks (Aug 25)
- RE: Is it time to abandon bogon prefix filters? Sean Donelan (Aug 26)
- Re: Is it time to abandon bogon prefix filters? Kevin Loch (Aug 19)
- Re: Is it time to abandon bogon prefix filters? Pekka Savola (Aug 19)