nanog mailing list archives
Re: BGP advertise-best-external on RR
From: dip <diptanshu.singh () gmail com>
Date: Tue, 1 Sep 2015 23:12:45 -0500
There's no such thing as free lunch right :). If BGP Add-Path or Diverse-Path isn't option for you then as you mentioned Internet VRF with different RD is the third option but you have to understand the implications here as well around increase in % of memory. Another option could be to bypass the RR's and just fully mesh it. But if none of the above is an option, then you may have to do some unnatural act to solve it. On Tue, Sep 1, 2015 at 7:51 AM, Mohamed Kamal <mkamal () noor net> wrote:
Hi, Diverse-path will only send the second best path, and in my case I have three routes not two. In addition to that, every PE will have to peer with the RR via a second session (on the same RR, as I will not deploy a new standalone shadow RR) and this will increase the BGP sessions to the double. Add-path will have a network-wide IOS upgrade for this BGP capability to be supported which is not viable now. So, is there any other recommendation other than the internet VRF with different RDs solution? Regards, Mohamed Kamal Core Network Sr. Engineer On 8/25/2015 11:37 AM, Jeff Tantsura wrote:Hi, In your case I¹d recommend to use diverse path, due to its simplicity and non disruptive deployment characteristics. As you know - diverse path requires additional BGP session per additional (second, next, etc) path, in most cases not a problem, however mileage might vary. To my memory, in Cisco land - it has only been implemented in IOS, not XR, please check. Cheers, Jeff -----Original Message----- From: Diptanshu Singh <diptanshu.singh () gmail com> Date: Monday, August 24, 2015 at 10:53 PM To: Mohamed Kamal <mkamal () noor net> Cc: "nanog () nanog org" <nanog () nanog org> Subject: Re: BGP advertise-best-external on RR Yes . In the case of diverse path , shadow route reflector will be theone wherever you enable commands to trigger diverse path computation. Good thing with diverse path is that the RR-Clients don't have to have any support but bad thing is that it can only reflect One additional best-path( second best path ) . Sent from my iPhone On Aug 24, 2015, at 2:31 PM, Mohamed Kamal <mkamal () noor net> wrote:It's only supported on the 15.2(4)S and later not the SRE train. I might consider an upgrade. One more question regarding this, can you configure the RR to be the main and shadow RR? Mohamed Kamal Core Network Sr. Engineer On 8/24/2015 9:16 PM, Diptanshu Singh wrote:BGP Add-Path might be your friend . You can look at diverse-path as well .
Current thread:
- Re: BGP advertise-best-external on RR Mohamed Kamal (Sep 01)
- Re: BGP advertise-best-external on RR dip (Sep 01)
- Re: BGP advertise-best-external on RR Baldur Norddahl (Sep 02)
- Re: BGP advertise-best-external on RR Mark Tinka (Sep 02)
- <Possible follow-ups>
- RE: BGP advertise-best-external on RR Jakob Heitz (jheitz) (Sep 05)