Service Providers behaviour for dual homed enterprises

Thu Sep 24 13:21:02 UTC 2015

On Wed, Sep 23, 2015 at 5:38 PM, Jason Bullen <jmbullen21 at gmail.com> wrote:
> So if my research is correct, the internet prefers Verizon UNLESS they are
> a direct AT&T customer then they would use the AT&T circuit.
> Is this a standard practice that I should assume to encounter?

Hi Jason,

That's normal. Verizon does it too. Both have "community" tags which
you can attach to your route advertisement. Each will have one that
indicates they should give external routes the same "local pref" as
the route you announce to them. Tagging your route announcement with
the proper community will cause them to route based on AS path length
as you expect.

Welcome to the little gotchas of using BGP.

Regards,
Bill Herrin

-- 
William Herrin ................ herrin at dirtside.com  bill at herrin.us
Owner, Dirtside Systems ......... Web: <http://www.dirtside.com/>