[j-nsp] DSCP-marked traffic mysteriously being dropped by MX960

[John Neiberger]

On Fri, Jul 20, 2012 at 3:49 PM, Wayne Tucker <wayne at tuckerlabs.com> wrote:
> Does show interfaces <blah> extensive on the interface between Router A and
> Device A show any drops?  IIRC, the default scheduler map does not define
> schedulers for anything other than be and nc - so if you're classifying the
> packets on input then it could be that they're going to a class that has no
> resources on the egress interface.
>
> :w

This is certainly what is happening. I checked and saw that we're
seeing output drops in queue 1, but based on the reading I did
tonight, it sounds like the default is for 95% of the bandwidth to be
assigned to best effort in queue 0 and 5% is set aside for network
control in queue 3. The fact that we're seeing all those drops in
queue 1 pretty much proves the issues. We have some groups configured
that have the right scheduler map on them. I just need to determine
exactly which group is the right one and apply it to the right
interfaces.

I haven't had a chance to apply the fix yet, and all of the people who
have access to the end devices for testing are gone for the weekend,
but I wanted to thank everyone for the help on this. I'm pretty new to
Juniper and I (and everyone else looking at this, including JTAC) were
stumped.


Thanks again,
John