Best practice for BGP session/ full routes for customer

Jeff Tantsura jeff.tantsura at
Mon Jul 14 17:32:43 UTC 2014


BGP to RIB filtering (in any vendor implementation) is targeting RR which
is not in the forwarding path, so there¹s no forwarding towards any
destination filtered out from RIB.
Using it selectively on a forwarding node is error prone and in case of
incorrect configuration would result in blackholing.


-----Original Message-----
From: Mark Tinka <mark.tinka at>
Organization: SEACOM
Reply-To: <mark.tinka at>
Date: Tuesday, July 8, 2014 at 1:56 PM
To: "nanog at" <nanog at>
Subject: Re: Best practice for BGP session/ full routes for customer

>On Monday, July 07, 2014 08:33:12 PM Anurag Bhatia wrote:
>> In this scenario what is best practice for giving full
>> table to downstream?
>In our case, we have three types of edge routers; Juniper
>MX480 + Cisco ASR1006, and the Cisco ME3600X.
>For the MX480 and ASR1006 have no problems supporting a full
>table. So customers peer natively.
>The ME3600X is a small switch, that supports only up to
>24,000 IPv4 and 5,000 IPv6 FIB entries. However, Cisco have
>a feature called BGP Selective Download:
>Using BGP-SD, we can send a full BGP table from our route
>reflectors to our ME3600X switches, without worrying about
>them entering the FIB, i.e., they are held only in memory.
>The beauty - you can advertise these routes to customers
>natively, without clunky eBGP Multi-Hop sessions running
>Of course, with BGP-SD, you still need a 0/0 + ::/0 route in
>the FIB for traffic to flow from your customers upstream,
>but that is fine as it's only two entries :-).
>If your system supports a BGP-SD-type implementation, I'd
>recommend it, provided you have sufficient control plane

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