Default routes on BGP routers with full feeds

William Herrin bill at
Wed Nov 5 19:39:16 UTC 2014

On Tue, Nov 4, 2014 at 12:47 PM, Berry Mobley <berry at> wrote:
> I'm wondering how many of you who are multihomed
> also add default routes pointing to your providers
> from whom you are receiving full feeds.
> If so, why? If not, why not?

Back when I worked for the DNC we ran into a problem with the TCAM size.
Given the DNC's focus on the U.S., network reliability to the /8's operated
out of the APNIC and RIPE regions was much less important to us. So, we
filtered BGP announcements from within those /8's and relied on covering
routes to get our packets there instead.

I used covering /8's instead of a default, but a default would have been as

Bill Herrin

William Herrin ................ herrin at  bill at
Owner, Dirtside Systems ......... Web: <>
May I solve your unusual networking challenges?

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