Yes I see now I have worded it miserably :) What I got on my mind was an eBGP session to stub site /single homed customer. Now that I think about it I believe it could have been "on" by default on all the router interfaces and would have to be turned off manually(or automatically if mpls is enabled on the interface) for core interfaces and interfaces facing dual-homed sites. Anyways disabling urpf would than soon become a part of standard interface-config templates. So I guess no matter what tools we'd have it boils down to (and I don't want to use a word "laziness") maybe comfortability of operators.
adam -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of William Herrin Sent: Thursday, March 28, 2013 2:43 PM To: Adam Vitkovsky Cc: Saku Ytti; [email protected] Subject: Re: BCP38 - Internet Death Penalty On Thu, Mar 28, 2013 at 8:20 AM, Adam Vitkovsky <[email protected]> wrote: > It's a pity that rpf is not "on" by default for interfaces over which > the ebgp session is configured. Hi Adam, Considering that's one of the key scenarios for which RPF is known to NOT WORK reliably, I would have to disagree with that statement. Folks running BGP expect to manipulate routes asymmetrically. If you had said, "It's a pity that RPF is not on by default over interfaces for which no routing protocol is configured (connected and static routes only)" I might have agreed with you. Regards, Bill Herrin -- William D. Herrin ................ [email protected] [email protected] 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004
