Cisco Systems UBR10012 Interrupts are Consuming a Large Amount of Resources, IP Input Processing

%IPCGRP-6-NOKEEP: Too long since a keepalive

Chapter 3 Troubleshooting PRE-1 Modules

Troubleshooting Common System Problems

For information on resolving problems with high CPU usage caused by the Exec and Virtual EXEC processes, see the document High CPU Utilization in Exec and Virtual Exec Processes, at the following URL:

http://www.cisco.com/en/US/products/hw/routers/ps359/products_tech_note09186a00801c2ae4.shtml

Interrupts are Consuming a Large Amount of Resources

Interrupts allow software processes to request resources when needed, as opposed to waiting for time to be allocated to the process. If a process requests too many interrupts, however, it could impact CPU usage, resulting in less time available to other processes.

For more information, see the document Troubleshooting High CPU Utilization Due to Interrupts, at the following URL:

http://www.cisco.com/en/US/products/hw/routers/ps359/products_tech_note09186a00801c2af0.shtml

Invalid Scheduler Allocate Configuration

The scheduler allocate command guarantees the minimum amount of time that can be allocated for fast-switching during each network interrupt context, and the minimum amount of time that can be allocated for non-interrupt-driven processes. An incorrect configuration for the scheduler allocate command can cause high CPU usage, especially when too much time is allocated for non-interrupt processes. This could result in messages such as

was received from the PRE.

We recommend using the default configuration, which can be restored by giving the default scheduler allocate command in global configuration mode:

Router(config)# default scheduler allocate

Router(config)#

IP Input Processing

The Cisco IOS software uses a process named IP input to process IP packets that cannot be processed using the fast-switching process. If the router is process-switching a lot of IP traffic, it could result in excessively high CPU usage.

The most common reasons for excessive IP Input processing are that fast-switching has been disabled on one or more interfaces, and that the router is receiving a large volume of traffic that must be process-switched. For more information on resolving problems with the IP Input process, see the Troubleshooting High CPU Utilization in IP Input Process document at the following URL:

http://www.cisco.com/en/US/products/hw/routers/ps359/products_tech_note09186a00801c2af3.shtml

One or More Processes is Consuming an Excessive Amount of Resources

High CPU usage could occur if one or more processes is consuming an excessive amount of resources. For example, the router might have an excessive number of TCP connections open, or the TTY background process is busy displaying logging or debugging messages.

Cisco uBR10012 Universal Broadband Router Troubleshooting Guide

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