Cisco ISE - Line Card ISE Configuration Manual page 83

Software Configuration of ATM ISE Line Cards for Cisco 12000 Series Routers
Improper queueing configuration, using the queue-limit or random-detect commands, allows for long
queues to build up in the SAR. In this case, if some VCs are oversubscribed, their queues might
eventually exhaust the TX cell buffer pool. When no TX cell buffers are available, no VC can enqueue
outbound packets, including such VCs that are not oversubscribed; that is, VC isolation is not
maintained. This can be confirmed by checking the following counters while tx_resource_err is
incrementing:
•
•
In a properly configured system, the tx_resource_err counter of a VC should only be incrementing when
this specific VC is oversubscribed and dropping packets because the queue limit is being exceeded or
because of WRED operation. This can be confirmed by checking the following counters while
tx_resource_err is incrementing:
•
•
The above will be observable easily on a VC that is constantly oversubscribed, so that (some of) its
Note
queues are never completely drained. However, if the traffic sent to the VC is highly bursty, then the
queues might be building up momentarily, but be completely drained by the time the counters are
displayed. In this case, tx_resource_err will increment, even though the queue depth might be small (or
zero) at the time it is displayed. It is therefore recommended to sample the counters several times before
drawing conclusions.
Upgrading the FPGA Image
If the line card does not boot and you receive an error message indicating that there is a problem with
the Field-Programmable Gate Array (FPGA) image (or if the line card alphanumeric LED display
remains frozen in IOS STRT state), you need to upgrade the FPGA image using the update-fpga option
in the diag command.
The diag command and the update-fpga option are documented in the
Note
12000 Series Internet Router
When the Cisco IOS image boots, it verifies that a compatible FPGA image is running on the router. The
major version number of the FPGA image must be the same as that expected by the Cisco IOS image;
the minor version number on the FPGA image must be the same as or greater than the minor version
number expected by the Cisco IOS image. For example, if the Cisco IOS image expects a minimum
FPGA image of 03.02, the software will verify that the actual major version number of the FPGA image
in the line card bootflash is 03, and that the minor version number is 02 or above.
the tx_queue_depth counter should be zero and
the tx_random_drops and tx_thresh_drops should be constant, not incrementing.
If queue limit is configured on the VC, the tx_queue_depth counter should be non-zero, up to the
configured queue limit at maximum.
If WRED is configured, then tx_queue_depth should be non-zero, and either tx_random_drops or
tx_thresh_drops (or both) will also be incrementing.
publication.
Troubleshooting ATM Errors on the 4-Port ATM ISE Line Card
Field Diagnostics for the Cisco
Cisco IOS Release 12.0(27)S
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