[166343] in North American Network Operators' Group
Re: clear forwarding route
daemon@ATHENA.MIT.EDU (Joe Abley)
Fri Oct 18 12:42:28 2013
From: Joe Abley <jabley@hopcount.ca>
In-Reply-To: <CAG1kdogOyEVeKhhDm3oOsvuHiJEnCEz=uYWjZY+DwKvKpzBLeg@mail.gmail.com>
Date: Fri, 18 Oct 2013 12:42:12 -0400
To: Manav Bhatia <manavbhatia@gmail.com>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On 2013-10-18, at 11:40, Manav Bhatia <manavbhatia@gmail.com> wrote:
> I would like understand the circumstances under which an operator may =
want
> to clear all (or a subset of) the routes programmed in the forwarding =
table
> (FIB).
Because of bugs which have led to the FIB containing data that doesn't =
match the RIB, and which is causing customer enragement. They don't call =
it CEF for nothing.
> I believe the command to do this on Cisco is
>=20
> clear forwarding {ipv4 | ipv6} route {* | prefix} [vrf vrf-name] =
module
> {slot| all}
Cool. Back when I was chasing packets at 6461 the best we could do was
router(config)# interface blah
router(config-if)# shutdown
router(config-if)# no shutdown
> I ask this since doing this would result in the router dropping all =
transit
> traffic till the routes get reprogrammed in the FIB.
Seems likely!
> Why would somebody ever want to do this?
Screaming customer on the phone.
Joe=
