Re: Opinions on Arista for BGP?

[Jeff Tantsura <jefftant.ietf () gmail com>]

Important note - Arista has 2 BGP implementations in the routing stack, old (NH/ribd) that has been there since day 1 
and newly written  (I believe mostly driven by EVPN development), when compared to other vendors - make sure to compare 
with the new (modern code, highly multithreaded, cache optimized) implementation.

Cheers,
Jeff

> On Apr 1, 2022, at 11:10, Adam Thompson <athompson () merlin mb ca> wrote:
>
> 
> TL;DR: Yes, go ahead, they’re good, we like them.
>  
> I won’t say they’re perfect, but we’re using them at the edge (two of them in a hybrid core/edge model right now, 
> even!) and I would happily endorse them for edge routers.  Their BGP stack hasn’t put up any major roadblocks for us 
> so far (at least, that weren’t, ahem, self-inflicted).  We’ve had 1 incident in the last ~2 years where a stuck route 
> on one router needed a full reboot to clear out, following a partial outage - that’s the worst thing I can remember 
> right now.
>  
> Don’t know if you know this already or not, so making it clear:  the one thing to beware of IMO, compared to e.g. a 
> high-end Juniper MX960-style system where you can turn every single feature on without caring, is that the Aristas 
> can do almost anything you can dream of… but not necessarily all at the same time on the same box, no matter which 
> model you’re looking at.
> So if you use it as an edge router?  Fine.  As a VXLAN gateway?  Fine.  As a core router or switch with every kind of 
> accounting turned on?  Fine.  All of those things simultaneously?  Maaaaaybe.  It’ll be decision time for which 
> specific, individual sub-features you can live without.  But you’re paying 1/10th (probably less!) of what you would 
> for an MX960, so there you go.
>  
> If this helps, they’re similar to the Cisco Nexus platform in this regard, e.g. if you enable and use every single 
> “Feature” on the fixed-configuration Nexuses you’ll start running out of hardware configuration resources to enable 
> them long before you can finish configuring or using all those features.
>  
> This is something your Arista SE can go through with you in excruciating detail (keyword: “TCAM Profile”), if you 
> think you might be veering into that territory.  After lots of iterations, and a new software release or two, our 
> all-in-one boxes (7280SR2K) do more or less everything we want them to.  (Apparently we aren’t typical Arista 
> customers.  Go figure.)  If you want to do BGP and MLAG at the same time on the same box, get your SE involved from 
> the start.
>  
> For anyone not trying to overload the platform or do too much “weird” stuff, it should be a quick and easy deployment 
> producing much happiness.
>  
> -Adam
>  
>  
> Adam Thompson
> Consultant, Infrastructure Services
>
> 100 - 135 Innovation Drive
> Winnipeg, MB, R3T 6A8
> (204) 977-6824 or 1-800-430-6404 (MB only)
> athompson () merlin mb ca
> www.merlin.mb.ca
>  
> From: NANOG <nanog-bounces+athompson=merlin.mb.ca () nanog org> On Behalf Of David Hubbard
> Sent: Thursday, March 31, 2022 8:10 AM
> To: nanog () nanog org
> Subject: Opinions on Arista for BGP?
>  
> Hi all, would love to get any current opinions (on or off list) on the stability of Arista’s BGP implementation these 
> days.  Been many years since I last looked into it and wasn’t ready for a change yet.  Past many years have been IOS 
> XR on NCS5500 platform and Arista everywhere but the edge.  I’ve been really happy with them in the other roles, so 
> am thinking about edge now.  I do like and use XR’s RPL, and prefix/as/community/object sets, but we can live without 
> via our own config management if there aren’t easy equivalents.  No fancy needs at all, just small web server 
> networks, so just need reliable eBGP and internal OSPF/OSPFv3.
>  
> Thanks,
>  
> David