[c-nsp] no packet loss until BGP is brought up?!?

[Pete Templin]

Dennis Nugent wrote:

>   An existing client just changed their equipment to a Diamond msm3
> We have a Cisco 6503 with a Supe2msfc2
> Cat5 cross-connect to them for about a year with no issues with their old 
> router.  When we do extended pings to the new  interface, there is no 
> packet loss.
> As soon as he brings up BGP, we get 17 - 25% packet loss.  Turn off BGP, 
> and packet loss goes back to 0.
> He has changed interfaces, etc.  When his BGP is up, there is no issue with 
> CPU or memory in his Diamond.
> 
> He is also doing BGP with other upstreams, and states that he is not seeing 
> any packet loss to the other upstream providers.
> 
> Has anyone else seen anything like this?  Besides the obvious, any 
> recommendations?

Had a very similar situation where we had a duplex settings mismatch. 
Pings weren't enough to find it, but the traffic load "in production" 
was more than capable of exposing it.

pt