31 Mar
2020
31 Mar
'20
2:39 a.m.
On 3/31/20 2:25 AM, R P via 44Net wrote:
Is it possible to announce same Address Block from
two different sites ?
Yes.
with preferred way for one site ?
Yes
The idea is to have redundancy in case that one site
connectivity fail the traffic will pass to the other site automatically
Both site will be connected by radio as well so Network connectivity will not stop
I know that BGP support it is it also the way in the AMPRNET BGP announcement ?
Yes
Has anyone done it ? or doing it in the AMPRNET
community ?
Yes.
Basically you want to announce to two upstream ISP's with two different ASN's,
each is at a different site (could be the same site too). You want one path
to be primary/active and the other to be secondary/standby.
What you do is setup your secondary connection to "prepend" your ASN on the
announcement to your secondary ISP. The AS path to the rest of the internet
will be ISPA-YOU for the primary and ISPB-YOU-YOU for the secondary. Under
normal conditions no traffic will come in the ISPB link as the AS path is
longer.
You'll need to control outbound using local pref or other methods. Are you
taking full tables or just a default route?
--
Bryan Fields
727-409-1194 - Voice
http://bryanfields.net