[j-nsp] New 16port 10G Card and new MPC with 4x10G MIC Cards - coexistance of old DPCs and new Cards in same chassis -- looking for experience feedback

[Richard A Steenbergen]

On Thu, Aug 26, 2010 at 01:10:37PM +0200, Prochaska Gerhard wrote:
> Hi !
> 
> We are planning to mix DPCs and new Linecards in the same chassis. As 
> far as i understand this is possible from Junos 10.2R2 upwards.
>
> We plan to use both types of cards to increase port density on our ISP 
> Nodes where we are short of free slots.
> 
> So from the Service Point of View iBGP. eBGP, OSPF and Carriers 
> Carrier are the main topics.
> 
> Im looking for feedback what problems other providers have already 
> encounterd.

We have several Trio cards in the earliest stages of deployment, doing 
some pretty simple carrier-grade IPv4 + IPv6 + MPLS under relatively 
minor load (probably less than 20Gbps of traffic tops).

So far we've seen:

* FPCs that crash when you configure certain firewall match criteria and 
apply it to an interface (time-exceed-bit, for anyone who cares).

* SNMP stop responding after RE switchovers, requiring a manual restart 
of the mib2d process to restore. Was supposed to be fixed in 10.2R2, but 
we're still seeing it.

* Occasionally the logical subinterface counters will return wildly 
incorrect data, then mysteriously fix itself on its own after a couple 
days. We've had difficulty reproducing this one, but I've heard reports 
of this exact same issue from others doing the same testing, so it can't 
be THAT big of a fluke. :)

* When running MPLS with path-mtu allow-fragmentation configured, 
IPv4->MPLS encapsulating packets will be blackholed. Disable 
allow-fragmentation as a workaround, should be fixed in 10.2R3.

* At one point we saw blackholing of packets across the PFE following an 
FPC crash, with GRES enabled. Issue went away when you rebooted the 
backup RE, came back as soon as the backup came back up and tried to 
start syncing again, cleared up again after turning GRES off. I've seen 
this issue on and off across several versions of code though, so it 
might not be Trio specific.

As far as reliability goes... I can say that at this exact moment we 
have no outstanding unresolved issues that are currently impacting our 
Trio test boxes which can't be worked around... BUT, every time we've 
turned up a new feature or activated a new service on them we've 
discovered something new, so I can't vouch that there aren't more issues 
out there waiting to be discovered. :) Oh and this is a Trio-only 
deployment, I also can't speak to any additional bugs which will occur 
when you try to mix ADPC and Trio cards, but I'd be willing to bet money 
there are some out there. I'm also hoping they will have a service 
release before 10.2R3, since there are a few other non-Trio related bugs 
we've found in other code which aren't fixed in 10.2R2.

-- 
Richard A Steenbergen <ras at e-gerbil.net>       http://www.e-gerbil.net/ras
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)