[c-nsp] ASR1K forwarding failures on 10G SPA's

[Stephen Fulton]

Hi all,

I have run into a number of forwarding failure events on ASR1K's with 
10G SPA's.  These have occurred across a range of IOS-XE versions, using 
various ROMMON versions and across two different ASR1K platforms (1002's 
and 1004's).  Multiple SPA's have been replaced, IOS-XE versions and 
ROMMON versions upgraded and in the case of the ASR1004's, SIP's 
replaced (both SIP10 and SIP40's).  TAC cases have been opened several 
times.

What occurs is forwarding across an interface fails completely.  The 
easiest way to find it is the lack of ARP entries on the 
interface/sub-interface, due to time-outs, but traffic is still 
attempting to traverse the interface.  When I ping the IP address 
associated with the failed interface, it fails.  ARP resolution of any 
neighbors fails, and neighboring devices on the same broadcast domain 
cannot reach it - though will see its MAC in the ARP table.

In all cases, ISIS and MPLS was configured on the interfaces.  BFD has 
been on some, not on others.

I recently found learned of another organization that saw the same 
behavior on an ASR1006 with 10G SPA's.  SPA's and SIP's were replaced 
and the last advice they received from TAC was that if it occurred again 
the chassis would need to replaced.  It did but they chose not to 
replace the chassis and simply stopped using 10G entirely.

Has anyone else seen this?

-- Stephen