[c-nsp] CSCuy29638 - MPLS (for IPv4) Brokenness Fixed - ASR920

[Eric Van Tol]

> I'd recommend anyone running an ASR920, particularly one adjacent to a
> Junos-based device, upgrades to this code to avoid pain.
> 

FYI, we upgraded to this version last week on several of our ASRs. Since then, we've had two 'lock-ups'. ISIS, BFD, and LDP all establish (albeit inconsistently) and even ISIS database is populated, but no LDP label advertisement occurs. Pings to any IPs on the ASR die, but some transit traffic works. Sometimes BGP re-establishes after an interface reset or ISIS clearing, but it's not consistent.

Captures on the opposite side of the link show ARP requests coming in for the next-hop and responses being sent, but doesn't look like they are received, or if they are, they are not getting into the ARP table. Unfortunately, haven't had much time to actually troubleshoot the issue before needing to restore service (with a reboot), so I don't have a ton of data to go by.

This is vaguely similar to an issue I posted about a couple of months ago, but in this latest instance, some protocol sessions appear to remain up, for the most part. In that issue, no protocols were up at all.

Only running v4, sometimes v4/v6, LDP, ISIS, BGP, BFD. They terminate Layer 3 right on the box, with a mix of L2circuits.

-evt