Hi, I'm having weird issues where the Foundry documentation is - uhm somewhat - lacking. So, perhaps someone here has run into a similar issue or has some pointers for me in order to wrap my brain around it.
According to the Foundry NI40G docs (well, the "if, then, else" game in that large PDF), by default "flow-control" (802.3x ethernet PAUSE frames) is on. But in order those PAUSE frames be send, you need to set a threshold (% buffers used) for when it will pause, a threshold for when packet will get dropped, and according to which scheme they should be dropped. This should all be done with "qd-flow"... In that same PDF (or the other guides I tried) I cannot find any mentioning of there being a default setting for "qd-flow", and would therefore be inclined to believe that without a default, these would not be send, or at least when the chassis or linecard buffers are completely depleted. Now, the fun part is that nowhere within "sh int" or "sh sta" there appears any mentioning of how many of those "flow-control" / 802.3x / PAUSE frames were sent or received. So, does anyone have any pointers as to if these can be found ? I'm reluctant to consider IronView (I don't like GUI's, and it doesn't fit our ICT environment for router maintenance) or need to resort to sFlow (it's still sampled, and I trust it more with L3) , since I'm of oppinion that this is such a fundamental L2 issue, it should show up somewhere in the CLI. Now, because you're wondering why: The situation where I'm in need of getting that information is as follows. My NI40G is connected via 10GE to a Nortel ERS8600R. And we've had - at that time reproducable - issues where at a seemingly random times (usually every 30 minutes tops, but even as low as after 2) the link would stall on L2. On both ends the link stays up (or at least doesn't trigger an SNMP trap or SYSLOG messsage), but traffic doesn't flow (counters don't increase etc.). BGP times out, other L2 (seperate VLAN) traffic stops for >30s... The only thing we were able to see, was at the Nortel end, where their Java GUI showed a bunch of "flow-control" packets. And when during those issues we disabled "flow-control" on the NI40G 10GE interface, problems ceased (for several hours), and when enable again, they started shortly. I've contacted my supplier on this issue, but apart from well, the most basic "did you do ..." replies from them (and Foundry support I would gather), they haven't even been able to tell me what the behaviour of the NI40G should be. In what cases will it send PAUSE frames, in what cases will it honour received PAUSE frames, etc. So, any ideas or pointers are very much appreciated. Kind regards, JP Velders
