nanog mailing list archives
different flavours of uRPF [RE: register.com down sev0?]
From: Pekka Savola <pekkas () netcore fi>
Date: Fri, 27 Oct 2006 09:50:09 +0300 (EEST)
On Thu, 26 Oct 2006, Tony Li wrote:
It was possible to implement BCP38 before the router vendors came up with uRPF.Further, uRPF is frequently a very inefficient means of implementing BCP 38. Consider that you're going to either compare the source address against a table of 200,000 routes or against a handful of prefixes that you've statically configured in an ACL.
Isn't that only a problem if you want to run a loose mode uRPF? Given that loose mode uRPF isn't very useful in most places where you'd like to do ingress filtering, this doesn't seem like a big issue.. BTW, I still keep wondering why Cisco hasn't implemented something like Juniper's feasible-path strict uRPF. Works quite well with multihomed and asymmetric routing as well -- no need to fiddle with communities, BGP weights etc. to ensure symmetry. -- Pekka Savola "You each name yourselves king, yet the Netcore Oy kingdom bleeds." Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings
Current thread:
- Re: register.com down sev0?, (continued)
- Re: register.com down sev0? Chris L. Morrow (Oct 26)
- Re: register.com down sev0? Randy Bush (Oct 26)
- Re: register.com down sev0? Gadi Evron (Oct 26)
- 10,352 active botnets (was Re: register.com down sev0? Valdis . Kletnieks (Oct 26)
- Re: 10,352 active botnets (was Re: register.com down sev0? Matthew Crocker (Oct 26)
- Re: 10,352 active botnets (was Re: register.com down sev0? Jack Bates (Oct 26)
- Re: register.com down sev0? Jared Mauch (Oct 26)
- Re: register.com down sev0? Daniel Senie (Oct 26)
- RE: register.com down sev0? Tony Li (Oct 26)
- different flavours of uRPF [RE: register.com down sev0?] Pekka Savola (Oct 26)
- Re: different flavours of uRPF [RE: register.com down sev0?] Tony Li (Oct 27)
- Re: different flavours of uRPF [RE: register.com down sev0?] Chris L. Morrow (Oct 27)
- Re: register.com down sev0? Gadi Evron (Oct 26)
- Re: register.com down sev0? Patrick W. Gilmore (Oct 26)
- Re: register.com down sev0? Randy Bush (Oct 26)
- Re: register.com down sev0? Michael . Dillon (Oct 27)