Hi there Is it possible to announce same Address Block from two different sites ? with preferred way for one site ? 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 ? Has anyone done it ? or doing it in the AMPRNET community ? Thanks Forward Ronen - 4Z4ZQ
Hi Ronen,
This is currently been done in several countries. The Netherlands does it, we in Belgium do it, and I cannot imagine that other countries don't do it. That is also what BGP is for. There should be no reason not to do it imo (unless you have cost restrictions of course).
73
Ruben ON3RVH
-----Original Message----- From: 44Net 44net-bounces+on3rvh=on3rvh.be@mailman.ampr.org On Behalf Of R P via 44Net Sent: Tuesday, March 31, 2020 08:26 To: 44net@mailman.ampr.org Cc: R P ronenp@hotmail.com Subject: [44net] BGP annuncement of same address Block from 2 sites ?
Hi there Is it possible to announce same Address Block from two different sites ? with preferred way for one site ? 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 ? Has anyone done it ? or doing it in the AMPRNET community ? Thanks Forward Ronen - 4Z4ZQ
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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?
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Bryan Fields -
R P -
Ruben ON3RVH