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Troubleshooting High Cpu Usage Cisco


This document provides details about the CPU packet-handling architecture and shows you how to identify the causes of high CPU utilization on these switches. Home Skip to content Skip to footer Worldwide [change] Log In Account Register My Cisco Worldwide Home Products & Services (menu) Support (menu) How to Buy (menu) Training & Events Thanks. Utilizing Multicast Multi-Layer Switching (MMLS), RPF traffic is usually forwarded by the hardware within the switch.

TagMan-RecreateMtegR 1.00 0.00 10 4 100 500 0 0 0 0:00 K2CpuMan Review 30.00 27.39 30 53 100 500 42 47 42 4841: K2AccelPacketMan: Tx 10.00 8.03 20 0 100 500 High CPU utilization because of this is Home Skip to content Skip to footer Worldwide [change] Log In Account Register My Cisco Worldwide Home Products & Services (menu) Support (menu) Unless you configure OAL, the process of packets that require logging takes place completely in software on the MSFC3. A full TCAM and increasing sw forwarding counts from the show controllers cpu-interface command output means that punted packets are causing high CPU utilization. click site

Troubleshooting High Cpu Utilization On Cisco Switches

number of unicast mac addresses: 3K number of igmp groups + multicast routes: 1K number of unicast routes: 11K number of directly connected hosts: 3K number of indirect routes: 8K number In order to implement this solution, place an access list on the incoming interface of the `stub network' to filter multicast traffic that did not originate from the `stub network'. The common misconception is that high CPU utilization indicates the depletion of resources on a device and the threat of a crash. High percentages in the show processes cpu command output If you have the output of a show processes cpu command from your Cisco device, you can use Cisco CLI Analyzerto display

Are there Topology Change Notifications (TCNs) in the network? This message is used to identify objects that use more CPU time than expected (but still not CPUHOG). Terminal length is set to something short (15 in this case), and the "q" character is sent only by prompt. How To Check Bandwidth Utilization On Cisco Router Please try again later.

Issue the show platform health command. Troubleshooting High Cpu Utilization Caused By Interrupts In this command output, you find that the top process is the Cat4k Mgmt LoPri : Switch#show processes cpu CPU utilization for five seconds: 99%/0%; one minute: 99%; five minutes: 99% Updated: May 29, 2008Document ID: 41120 Enterprise Networks Products Solutions Design Zone Architecture Services Case Studies Community Information For Small Business Midsize Business Service Provider Only three packets are shown.

If the largest block is larger than the half of the main:text region, use a granularity of 8. Show Memory Usage Cisco An example of these essential packets are bridge protocol data unit (BPDUs) for spanning-tree topology configurations. These are the CPU queues with their uses: rpc—Remote procedure call. The interrupt switch of traffic by the CPU causes the interrupt CPU utilization.

Troubleshooting High Cpu Utilization Caused By Interrupts

This diagram shows a Catalyst 4500 with three trunk ports that each carry VLANs 1 through 100. Catalyst 6500/6000 Switches do not use the CPU in the same way. Troubleshooting High Cpu Utilization On Cisco Switches The removal of routes does not help resume hardware switching. Ip Input High Cpu Yes No Feedback Let Us Help Open a Support Case (Requires a Cisco Service Contract) Related Support Community Discussions This Document Applies to These Products Catalyst 6500 Series Switches Share Information

The bug was identified in Cisco IOS Software Release 12.1(14)EA1a and is fixed on Cisco IOS Software Releases 12.2(25)SEA and later. HSRP flapping. Total packet queues 16 Packets Received by Packet Queue Queue Total 5 sec avg 1 min avg 5 min avg 1 hour avg ---------------------- --------------- --------- --------- --------- ---------- Esmp 0 In this case, a packet is routed through the same interface, which leads to the issue of an ICMP redirect for each packet. Hulc Led Process

While the switch might appear to operate fine at this CPU utilization level, when the switch CPU sustains a 50 percent utilization, its ability to react to dynamic network events is The larger number of packets forwarded through this tunnel increases CPU utilization. A high interrupt percentage indicates too much network traffic. have a peek at these guys Step 2 no logging console Disable logging to the console terminal.

Enter the show platform port-asic stats drop privileged EXEC command to see the CPU receive-queue discard counts and to identify the queue discarding packets. Fed Process Cisco On Cisco 7500 routers, Versatile Interface Processors (VIPs) and Route/Switch Processors (RSPs) do not report linear CPU utilization. Consider changing the SDM template.

Examples of this type of traffic include IPX RIP/Service Advertising Protocol (SAP), AppleTalk, and other broadcast traffic.

High CPU Due to IP SNMP Process In the latest Cisco IOS versions for Catalyst 3750, Simple Network Management Protocol (SNMP) requests are handled by the SNMP ENGINE. In other words, if the ACL does not fit into the TCAM, the ACE at the bottom portion of the ACL likely is not programmed in the TCAM. These two processes aggregate multiple platform-specific processes which perform the essential management functions on the Catalyst 4500. Cat4k Mgmt Lopri IPX traffic is hardware-switched on the Supervisor Engine 1A for both operating systems.

High CPU utilization as a result of low-priority packet processing or background processes is considered normal because the CPU constantly tries to use all the time available. For instance the CPU is receiving lots of packets from the hardware because there's a broadcast storm on the network. Issue the command under the relevant SVI or L3 interface. For the VTY line (Virtual Exec), the Telnet session has to build one TCP packet per character.

Use the interrupt percentage to determine if the problem is caused by a system process or high network traffic. The LCP schedular is part of the firmware code. Note:The port is 16/1 for supervisor engines in slot 2. In this example, the CPU utilization is 64 percent, and the interrupt percentage is 19 percent, which is high.The utilization problem is caused by the CPU processing too many packets received

Fix the cause for the loop. The output in this section shows that the control queue receives a lot of packets. In order to resolve this issue, disable these commands: set mls nde destination-ifindex disable set mls nde source-ifindex disable Use these commands to verify the values: show mls cef summary show Alternatively, an excessive amount of ARP requests can be caused by a malicious traffic stream which scans through locally attached subnets.

The CPU can receive multiple packet types and have multiple active system processes. Packets that match a deny ACE are sent to the CPU, which can cause high CPU utilization. show interfaces Command The command reference contains a detailed explanation of the show interfaces command. Issue the show processes cpu in order to check which Cisco IOS process consumes the CPU.

show platform port-asic stats drop Shows CPU packets discarded due to congestion. Does the router show symptoms of high CPU utilization at brief and unpredictable intervals? When the receive queue maximum is reached, the switch hardware discards packets destined for the congested queue. Note:Only Distance Vector Multicast Routing Protocol (DVMRP) tunnel interfaces are supported for multicast routing in the Catalyst 3750.