[j-nsp] One or more stream blocked

[Tarique A. Nalkhande - BMC]

Ross,

As aware, in the MX DPC there is a chip called the IChip (this is where all the data forwarding take place). Earlier there were some cases where IChip was dropping
the packets. To recover the chip from the 'wedge' state Juniper implemented a self-healing mechanism as a response to PR 228781 (and similar). Basically it
flushes the stuck stream and clears the problem. The I-Chip wedge detection mechanism can be sensitive under some circumstances. For example, if we have a situation where traffic flows in and not out (due to split horizon check inside the chip), it is taken to be 'wedge' condition and the stream is getting flushed (and we experience traffic loss). In this particular case there is traffic flowing into Ichip block, but it is all dropped entirely due to split-horizon check (i.e. for a legitimate reason). Ichip self healing code is getting confused and thinking chip is wedges and taking the corrective action (which is not required in this case). Juniper addressed this issue using an Internal PR#496620), this PR has the fix in : 10.0 R3, 10.1R2,10.2R1 etc...


Thanks & Regards
Tarique Abbas Nalkhande


-----Original Message-----
From: juniper-nsp-bounces at puck.nether.net [mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of Ross Vandegrift
Sent: 17 August, 2010 1:49 AM
To: juniper-nsp at puck.nether.net
Subject: [j-nsp] One or more stream blocked

Hello all,

Does this mean anything to anyone:

[Aug 16 22:41:12.103 LOG: Info] ICHIP (0) one or more stream blocked detected: 0x00000400

One MX we have is spamming this on a PFE console every second or two.
The index at the end if the same, always ICHIP 0.  From what I can tell poking around "stream" may refer to fabric streams.

This MX displays low, but consistent, packet loss.  No interface or PFE errors have accumulated.  Light levels are good.  Patch cables, panels, and transceivers have been replaced and tested.

Any info on whether or not the above constitutes a symptom (of hardware failure or misconfiguration) would be appreciated.  None of our other MXes behave this way.

Ross

--
Ross Vandegrift
ross at kallisti.us

"If the fight gets hot, the songs get hotter.  If the going gets tough, the songs get tougher."
	--Woody Guthrie

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