12406 IOS Monitoring Backplane

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Dec 23rd, 2009
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Each slot on the 12406 is limited to 10G to the backplane per slot. Do you know any commands or SNMP OID values we can monitor to make sure we don't hit the per slot limitation.

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mdwheadon Wed, 12/23/2009 - 07:30
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Thank you for the information however I am looking for a way to monitor the utilisation to the backplane to be proactive before backplane congestion occurs.

Do you know of any OID values or any other commands. The command you have provided appears to show us information when backplane congestion occurs ?

Giuseppe Larosa Wed, 12/23/2009 - 07:41
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the GSR is a distributed router with a crossbar switching fabric.

other specific commands are reported here:


What do the statistics in the show controllers frfab | tofab   queues output mean?

A. The packet memory on the Cisco 12000 Series Routers is divided into two       banks: ToFab and FrFab. The ToFab memory is used for packets that come in one       of the interfaces on the Line Card (LC) and make its way to the fabric, whereas       the FrFab memory is used for packets that are going out an interface on the LC       from the fabric.

These ToFab and FrFab queues are the most important concept to       understand in order to efficiently troubleshoot ignored packets in the 12000       Series Internet Router.

Note: ToFab (towards the fabric) and Rx (received by the router) are two           different names for the same thing, as are FrFab (from the fabric) and Tx           (transmitted by the router). For example, the ToFab Buffer Management           Application-Specific Integrated Circuit (ASIC) (BMA) is also referred to as the           RxBMA. This document uses the ToFab/FrFab convention, but you may see the Rx/Tx           nomenclature used elsewhere.

these are the parameters to look at, speaking of a generic backplane may be not appropriate for a GSR.

I couldn't find a reference but there are cases where if you have a slower linecard you need to apply QoS tools not on the ports but on fromfabric or tofabric direction to avoid problems.

Hope to help



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