[c-nsp] problem of both "ip route 0.0.0.0" and "ip default-gateway" configured

[Kim Onnel]

so if both are configured on a 3750 for example, there is no harm done?

On Jan 12, 2008 6:25 PM, Jon Lewis <jlewis at lewis.org> wrote:

> On Sat, 12 Jan 2008 sthaug at nethelp.no wrote:
>
> >> Someone mentioned that configuring both commands on the same
> router/switch
> >> causes trouble, i wonder if someone can help me understand why?
> >>
> >> 1) ip route 0.0.0.0 next-hop
> >> 2) ip default-gateway next-hop
> >
> > Why do you *want* to configure both? 1 is supposed to be used for an L3
> > box (router), 2 is supposed to be used for an L2 box (switch).
>
> AFAIK, ip default-gateway is only used when IP routing is off/unsupported.
> It can be useful if a device ends up booting into boot IOS that doesn't
> support routing (like some of the older run from flash platforms during a
> software upgrade where you have to reboot from ROM, download new code to
> flash, and then boot the new code).  I've got lots of gear with both a
> default route and an ip default-gateway and no problems.
>
> > If the interface in question is a broadcast medium (Ethernet), the
> router
> > doesn't know the next-hop address, resulting in a high rate of ARPs.
> This
> > has been dicussed on the list many times before, and the advice is
> simple:
> > Don't do it!
>
> It can work...but its very delicate and really pisses people off when
> someone with more clue is asked to take over management of the network.
>
> ----------------------------------------------------------------------
>  Jon Lewis                   |  I route
>  Senior Network Engineer     |  therefore you are
>  Atlantic Net                |
> _________ http://www.lewis.org/~jlewis/pgp<http://www.lewis.org/%7Ejlewis/pgp>for PGP public key_________
>