SV: Cisco NCS5501 as a P Router

Gustav Ulander gustav.ulander at
Sat May 27 14:42:37 UTC 2017

We are running 5001 also and we have the same issue with it programming the wrong entry into the hardware. 
Interesting to hear that the issue is still in 6.1.2 since we were thinking about upgrading to that one to see if it fixes the issue but I think we will give it a pass. 
Seems the BU cant find why its happening only that it indeed is happening. They don’t seem to be able to duplicate it in the lab either last we heard. 


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Från: NANOG [mailto:nanog-bounces at] För Radu-Adrian Feurdean
Skickat: den 27 maj 2017 11:31
Till: nanog at
Ämne: Re: Cisco NCS5501 as a P Router

On Thu, May 18, 2017, at 15:21, Erik Sundberg wrote:
> We're at the growing point where we need a dedicated P router for a 
> core device. We are taking a serious look at the NCS5501. Is there 
> anyone else using a NCS5501 as P Router or just general feedback on 
> the NCS5501 if you are using it?


While we're not using the NCS5501, we do use the "previous version", NCS5001. We're not yet at a point to care about the minuscule buffers.
Set-up : initially P-router in a very small BGP-free core (ISIS + LDP), then added route-reflector functionality too. 

As a P-router they usually behave correctly, except for the some cases where they start routing incorrectly (according to Cisco, the wrong label is programmed into hardware). That should have been fixed with 6.1.2, which we have deployed, until we recently had the same issue on 6.1.2, on the exact same box. We expect having some fun with the TAC about that.
> The big downside is it's only has a single processor

Yes, but:
 - it's powerful enough (we ended-up using them as RR too, and ~1.2M  routes in RIB pose no problem)
 - ours being about half the price of a 5501, we have 2 of them on every  site. If you can afford the same (2 / site) do it; If you don't -  review the copy so that you can (Brocade SLX 9540 looks like a good  alternative).

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