- CEF Overview
- Configuring Basic Cisco Express Forwarding
- Enabling or Disabling CEF or dCEF
- Configuring a Load-Balancing Scheme
- Configuring Epochs
- Configuring CEF Consistency Checkers
- Configuring CEF Network Accounting
- Customizing the Display of Recorded CEF Events
- Customizing the Display of CEF Event Trace Messages
- SNMP CEF-MIB Support
- Cisco Express Forwarding Command Changes
- CEF Enhancements
- IPv6 CEF-Switched Tunnels
Contents
- Customizing the Display of CEF Event Trace Messages
- Finding Feature Information
- Prerequisites for the Display of CEF Event Trace Messages
- Restrictions for the Display of CEF Event Trace Messages
- Information About the Display of CEF Event Trace Messages
- Cisco Platform Support for Central CEF and dCEF
- Overview of CEF Event Trace Function
- CEF Event Tracing Defaults and Options
- CEF Event Tracing for IPv4 Events
- CEF Event Tracing for IPv6 Events
- How to Customize the Display of CEF Event Trace Messages
- Customizing CEF Event Tracing
- Customizing CEF Event Tracing for IPv4 Events
- Customizing CEF Event Tracing for IPv6 Events
- Displaying CEF Event Trace Information
- Configuration Examples for the Display of CEF Event Trace Messages
- Example Customizing CEF Event Tracing
- Example Customizing CEF Event Tracing for IPv4 Events
- Example Customizing CEF Event Tracing for IPv6 Events
- Additional References
- Feature Information for the Display of CEF Event Trace Messages
- Glossary
Customizing the Display of CEF Event Trace Messages
This module contains information about and instructions for customizing the display of recorded Cisco Express Forwarding events for Cisco IOS Releases 12.2(25)S, 12.2(33)SB, 12.2(33)SRA, 12.2.(33)SXH, 12.4(20)T, and later releases.
For information about and instructions for customizing the display of recorded Cisco Express Forwarding events for Cisco IOS releases prior to 12.2(25)S, 12.2(33)SB, 12.2(33)SRA, 12.2.(33)SXH, and 12.4(20)T, see Customizing the Display of Cisco Express Forwarding Events.
You can customize the Cisco Express Forwarding event-tracing message display by specifying the size of the file stored in memory or by choosing to display event trace messages by prefix and mask, by a specified interface, or by a Cisco Express Forwarding Virtual Private Network (VPN) routing and forwarding instance (VRF) for an IPv4 or IPv6 address family.
Cisco Express Forwarding is an advanced Layer 3 IP switching technology. It optimizes network performance and scalability for all kinds of networks: those that carry small amounts of traffic and those that carry large amounts of traffic in complex patterns, such as the Internet and networks characterized by intensive web-based applications or interactive sessions.
- Finding Feature Information
- Prerequisites for the Display of CEF Event Trace Messages
- Restrictions for the Display of CEF Event Trace Messages
- Information About the Display of CEF Event Trace Messages
- How to Customize the Display of CEF Event Trace Messages
- Configuration Examples for the Display of CEF Event Trace Messages
- Additional References
- Feature Information for the Display of CEF Event Trace Messages
- Glossary
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Prerequisites for the Display of CEF Event Trace Messages
Cisco Express Forwarding must be running on the networking device before you can customize the display of recorded Cisco Express Forwarding events.
Restrictions for the Display of CEF Event Trace Messages
If you enable Cisco Express Forwarding and then create an access list that uses the log keyword, the packets that match the access list are not Cisco Express Forwarding switched. They are fast switched. Logging disables Cisco Express Forwarding.
Information About the Display of CEF Event Trace Messages
For links to information about other Cisco Express Forwarding and distributed Cisco Express Forwarding features that you can configure, go to the Additional References.
- Cisco Platform Support for Central CEF and dCEF
- Overview of CEF Event Trace Function
- CEF Event Tracing Defaults and Options
Cisco Platform Support for Central CEF and dCEF
Cisco Express Forwarding is enabled by default on most Cisco platforms running Cisco IOS software Release 12.0 or later. When Cisco Express Forwarding is enabled on a router, the Route Processor (RP) performs the express forwarding.
To find out if Cisco Express Forwarding is enabled on your platform, enter the show ip cefcommand. If Cisco Express Forwarding is enabled, you receive output that looks like this:
Router# show ip cef
Prefix Next Hop Interface
[...]
10.2.61.8/24 192.168.100.1 FastEthernet1/0/0
192.168.101.1 FastEthernet6/1
[...]
If Cisco Express Forwarding is not enabled on your platform, the output for the show ip cefcommand looks like this:
Router# show ip cef %CEF not running
Distributed Cisco Express Forwarding is enabled by default on the Catalyst 6500 series switch, the Cisco 7500 series router, and the Cisco 12000 Series Internet Router. When distributed Cisco Express Forwarding is enabled on your platform, the line cards perform the express forwarding.
If Cisco Express Forwarding is not enabled on your platform, use the ip cefcommand to enable (central) Cisco Express Forwarding or the ip cef distributed command to enable distributed Cisco Express Forwarding.
Overview of CEF Event Trace Function
The Cisco Express Forwarding event trace function collects Cisco Express Forwarding events as they occur, even when debugging is not enabled. This function allows the tracing of an event immediately after it occurs. Cisco technical personnel can use the event trace function to help resolve any problems with the Cisco Express Forwarding feature.
Cisco Express Forwarding event trace messages are saved in memory on the device. When the event trace messages exceed the configured size, the newest message in the trace will begin to overwrite the older messages. You can use the following commands to change the capacity of the Cisco Express Forwarding event message file:
The monitor event-trace cef events sizeglobal configuration command allows you to increase or decrease the number of messages that can be written to memory for a single instance of a trace. To display the size parameter, use the show monitor event-trace events parameters command.
The monitor event-trace cef events clear privileged EXEC command allows you to clear existing trace messages.
The monitor event-trace cef(global) command configures event tracing for Cisco Express Forwarding events. To monitor and control the event trace function for Cisco Express Forwarding events, use the monitor event-trace cef (EXEC) command.
You can use the following commands to display Cisco Express Forwarding events:
The show monitor event-trace cef allcommand displays all event trace messages currently in memory for Cisco Express Forwarding.
The debug ip cef command and the events keyword record general Cisco Express Forwarding events as they occur.
The debug ip cef tablecommand enables the real-time collection of events that affect entries in the Cisco Express Forwarding tables.
CEF Event Tracing Defaults and Options
Event tracing for distributed Cisco Express Forwarding events is enabled by default. The Cisco IOS XE software allows Cisco Express Forwarding to define whether support for event tracing is enabled or disabled by default. The command interface for event tracing allows you to change the default value in one of two ways: using the monitor event-trace cefcommand in privileged EXEC mode or using the monitor event-trace cefcommand in global configuration mode.
To configure the file in which you want to save trace information, use the monitor event-trace cefcommand in global configuration mode. By default, the trace messages are saved in a binary format. If you want to save trace messages in ASCII format, possibly for additional application processing, use the monitor event-trace cef dump pretty command in privileged EXEC mode. The amount of data collected from a trace depends on the trace message size configured using the monitor event-trace cefcommand in global configuration mode for each instance of a trace.
To specify the trace call stack at tracepoints, you must first clear the trace buffer.
CEF Event Tracing for IPv4 Events
Event tracing for Cisco Express Forwarding IPv4 events is enabled by default. The software allows Cisco Express Forwarding to define whether support for event tracing is enabled or disabled by default. The command interface for event tracing allows you to change the default value in one of two ways: using the monitor event-trace cef ipv4command in privileged EXEC mode or using the monitor event-trace cef ipv4command in global configuration mode.
To configure the file in which you want to save trace information for Cisco Express Forwarding IPv4 events, use the monitor event-trace cef ipv4command in global configuration mode. By default, the trace messages are saved in a binary format. If you want to save trace messages in ASCII format, possibly for additional application processing, use the monitor event-trace cef ipv4 dump pretty command in privileged EXEC mode. The amount of data collected from the trace depends on the trace message size configured using the monitor event-trace cef ipv4command for each instance of a trace.
To determine whether event tracing is enabled by default for Cisco Express Forwarding, use the show monitor event-trace cef ipv4command to display trace messages.
To specify the trace call stack at tracepoints, you must first clear the trace buffer.
CEF Event Tracing for IPv6 Events
Event tracing for Cisco Express Forwarding IPv6 events is enabled by default.The Cisco IOS XE software allows Cisco Express Forwarding to define whether support for event tracing is enabled or disabled by default. The command interface for event tracing allows you to change the default value in one of two ways: using the monitor event-trace cef ipv6command in privileged EXEC mode or using the monitor event-trace cef ipv6command in global configuration mode.
To configure the file in which you want to save trace information for Cisco Express Forwarding IPv6 events, use the monitor event-trace cef ipv6command in global configuration mode. By default, the trace messages are saved in a binary format. If you want to save trace messages in ASCII format, possibly for additional application processing, use the monitor event-trace cef ipv6 dump pretty command in privileged EXEC mode. The amount of data collected from the trace depends on the trace message size configured using the monitor event-trace cef ipv6command for each instance of a trace.
To determine whether event tracing is enabled by default for Cisco Express Forwarding, use the show monitor event-trace cef ipv6command to display trace messages.
To specify the trace call stack at tracepoints, you must first clear the trace buffer.
How to Customize the Display of CEF Event Trace Messages
- Customizing CEF Event Tracing
- Customizing CEF Event Tracing for IPv4 Events
- Customizing CEF Event Tracing for IPv6 Events
- Displaying CEF Event Trace Information
Customizing CEF Event Tracing
Perform the following task to customize Cisco Express Forwarding event tracing. Event trace messages can be used to monitor Cisco Express Forwarding and to help resolve any issues with the Cisco Express Forwarding feature.
1.
enable
2.
configure
terminal
3.
monitor
event-trace
cef
{dump-file dump-file-name | {events | interface} {disable | dump-file dump-file-name| enable | size number | stacktrace [depth]}}
4.
exit
5.
monitor
event-trace
cef
{dump [merged pretty | pretty] | {events | interface | ipv4 | ipv6} {clear | continuous [cancel] | disable | dump [pretty] | enable | one-shot}}
6.
disable
DETAILED STEPS
Customizing CEF Event Tracing for IPv4 Events
Perform the following task to customize Cisco Express Forwarding event tracing for Cisco Express Forwarding IPv4 events. Use event tracing to monitor Cisco Express Forwarding IPv4 events as they occur and to help resolve any issues with Cisco Express Forwarding and related IPv4 events.
1.
enable
2.
configure
terminal
3.
monitor
event-trace
cef
ipv4
{disable | distribution |dump-file dump-file-name| enable | match {global | ip-address mask} | size number | stacktrace [depth] | vrf vrf-name [distribution | match {global | ip-address mask}]}
4.
exit
5.
monitor
event-trace
cef
ipv4
{clear | continuous [cancel] | disable | dump [pretty] | enable | one-shot}
6.
disable
DETAILED STEPS
| Command or Action | Purpose | |||
|---|---|---|---|---|
| Step 1 |
enable
Example: Router> enable |
Enables privileged EXEC mode.
| ||
| Step 2 |
configure
terminal
Example: Router# configure terminal |
Enters global configuration mode. | ||
| Step 3 |
monitor
event-trace
cef
ipv4
{disable | distribution |dump-file dump-file-name| enable | match {global | ip-address mask} | size number | stacktrace [depth] | vrf vrf-name [distribution | match {global | ip-address mask}]} Example: Router(config)# monitor event-trace cef ipv4 size 10000 |
Configures event-tracing for Cisco Express Forwarding IPv4 events.
| ||
| Step 4 |
exit
Example: Router(config)# exit |
Exits to privileged EXEC mode. | ||
| Step 5 |
monitor
event-trace
cef
ipv4
{clear | continuous [cancel] | disable | dump [pretty] | enable | one-shot} Example: Router# monitor event-trace cef ipv4 continuous |
Monitors and controls the event trace function for Cisco Express Forwarding IPv4 events.
| ||
| Step 6 |
disable
Example: Router# disable |
Exits to user EXEC mode. |
Customizing CEF Event Tracing for IPv6 Events
Perform the following task to customize Cisco Express Forwarding event tracing for Cisco Express Forwarding IPv6 events.Use event tracing to monitor Cisco Express Forwarding IPv6 events as they occur and to help resolve any issues with Cisco Express Forwarding and related IPv6 events.
1.
enable
2.
configure
terminal
3.
monitor
event-trace
cef
ipv4
{disable | distribution | dump-file dump-file-name| enable | match {global | ipv6-address/n} | size number | stacktrace [depth] | vrf vrf-name [distribution | match {global | ipv6-address/n}]}
4.
exit
5.
monitor
event-trace
cef
ipv6
{clear | continuous [cancel] | disable | dump [pretty] | enable | one-shot}}
6.
disable
DETAILED STEPS
| Command or Action | Purpose | |||
|---|---|---|---|---|
| Step 1 |
enable
Example: Router> enable |
Enables privileged EXEC mode.
| ||
| Step 2 |
configure
terminal
Example: Router# configure terminal |
Enters global configuration mode. | ||
| Step 3 |
monitor
event-trace
cef
ipv4
{disable | distribution | dump-file dump-file-name| enable | match {global | ipv6-address/n} | size number | stacktrace [depth] | vrf vrf-name [distribution | match {global | ipv6-address/n}]} Example: Router(config)# monitor event-trace cef ipv6 match global |
Configures event-tracing for Cisco Express Forwarding IPv6 events.
| ||
| Step 4 |
exit
Example: Router(config)# exit |
Exits to privileged EXEC mode. | ||
| Step 5 |
monitor
event-trace
cef
ipv6
{clear | continuous [cancel] | disable | dump [pretty] | enable | one-shot}} Example: Router# monitor event-trace cef ipv6 one-shot |
Monitors and controls the event trace function for Cisco Express Forwarding IPv6 events.
| ||
| Step 6 |
disable
Example: Router# disable |
Exits to privileged EXEC mode. |
Displaying CEF Event Trace Information
Perform the following task to display Cisco Express Forwarding event trace information.
1.
enable
2.
monitor
event-trace
cef
events
clear
3.
debug
ip
cef
table
4.
show
monitor
events-trace
cef
all
5.
show
monitor
event-trace
cef
latest
6.
show
monitor
event-trace
cef
events
all
7.
show
monitor
event-trace
cef
interface
latest
8.
show
monitor
event-trace
cef
ipv4
all
9.
show
monitor
event-trace
cef
ipv6
parameters
10.
disable
DETAILED STEPS
| Step 1 |
enable
Use this command to enable privileged EXEC mode. Enter your password if prompted. For example: Example: Router> enable Router#
|
| Step 2 |
monitor
event-trace
cef
events
clear
Use this command to clear the Cisco Express Forwarding event trace buffer. For example:
Router# monitor event-trace cef clear
Example: |
| Step 3 |
debug
ip
cef
table
Use this command to display events that affect entries in the Cisco Express Forwarding tables. For example: Example: Router# debug ip cef table 01:25:46:CEF-Table:Event up, 10.1.1.1/32 (rdbs:1, flags:1000000) 01:25:46:CEF-IP:Checking dependencies of 0.0.0.0/0 01:25:47:CEF-Table:attempting to resolve 10.1.1.1/32 01:25:47:CEF-IP:resolved 10.1.1.1/32 via 10.9.104.1 to 10.9.104.1 Ethernet2/0/0 01:26:02:CEF-Table:Event up, default, 0.0.0.0/0 (rdbs:1, flags:400001) 01:26:02:CEF-IP:Prefix exists - no-op change |
| Step 4 |
show
monitor
events-trace
cef
all
Use this command to display event trace messages for Cisco Express Forwarding. For example: Example:
Router# show monitor event-trace cef all
cef_events:
*Jul 22 20:14:58.999: SubSys ipv4fib_ios_def_cap init
*Jul 22 20:14:58.999: SubSys ipv6fib_ios_def_cap init
*Jul 22 20:14:58.999: Inst unknown -> RP
*Jul 22 20:14:58.999: SubSys fib_ios_chain init
*Jul 22 20:14:59.075: SubSys fib init
*Jul 22 20:14:59.075: SubSys ipv4fib init
*Jul 22 20:14:59.075: SubSys fib_ios init
*Jul 22 20:14:59.075: SubSys fib_ios_if init
*Jul 22 20:14:59.075: SubSys ipv4fib_ios init
*Jul 22 20:14:59.075: Flag Common CEF enabled set to yes
*Jul 22 20:14:59.075: Flag IPv4 CEF enabled set to yes
*Jul 22 20:14:59.075: Flag IPv4 CEF switching enabled set to yes
*Jul 22 20:14:59.075: GState CEF enabled
*Jul 22 20:14:59.075: SubSys ipv6fib_ios init
*Jul 22 20:14:59.075: SubSys ipv4fib_util init
*Jul 22 20:14:59.075: SubSys ipv4fib_les init
*Jul 22 20:15:02.907: Process Background created
*Jul 22 20:15:02.907: Flag IPv4 CEF running set to yes
*Jul 22 20:15:02.907: Process Background event loop enter
*Jul 22 20:15:02.927: Flag IPv4 CEF switching running set to yes
cef_interface:
*Jul 22 20:14:58.999: Et0/0 (hw 3) SWvecLES <unknown> (0x01096A3C)
*Jul 22 20:14:58.999: Et0/1 (hw 4) SWvecLES <unknown> (0x01096A3C)
*Jul 22 20:14:58.999: Et0/2 (hw 5) SWvecLES <unknown> (0x01096A3C)
*Jul 22 20:14:58.999: Et0/3 (hw 6) SWvecLES <unknown> (0x01096A3C)
*Jul 22 20:14:58.999: Et1/0 (hw 7) SWvecLES <unknown> (0x01096A3C)
*Jul 22 20:14:58.999: Et1/1 (hw 8) SWvecLES <unknown> (0x01096A3C)
*Jul 22 20:14:58.999: Et1/2 (hw 9) SWvecLES <unknown> (0x01096A3C)
*Jul 22 20:14:58.999: Et1/3 (hw 10) SWvecLES <unknown> (0x01096A3C)
*Jul 22 20:14:58.999: Se2/0 (hw 11) SWvecLES <unknown> (0x01096A3C)
*Jul 22 20:14:58.999: Se2/1 (hw 12) SWvecLES <unknown> (0x01096A3C)
.
.
.
The output is in table format where the first column contains a time stamp, the second column lists the type of event, and the third column lists the detail for the event. |
| Step 5 |
show
monitor
event-trace
cef
latest
Use this command to display only the event trace message that have been sent since the last instance of the show monitor event-trace cef command. For example: Example: Router# show monitor event-trace cef latest cef_events: cef_interface: *Jul 22 20:14:59.075: Se3/0 (sw 15) FlagCha 0x60C1 add puntLC *Jul 22 20:14:59.075: <empty> (hw 16) State down -> up *Jul 22 20:14:59.075: <empty> (hw 16) Create new *Jul 22 20:14:59.075: Se3/1 (hw 16) NameSet *Jul 22 20:14:59.075: Se3/1 (hw 16) HWIDBLnk Serial3/1(16) *Jul 22 20:14:59.075: Se3/1 (hw 16) RCFlags None -> Fast *Jul 22 20:14:59.075: <empty> (sw 16) VRFLink IPv4:id0 - success *Jul 22 20:14:59.075: <empty> (sw 16) State deleted -> down *Jul 22 20:14:59.075: <empty> (sw 16) Create new *Jul 22 20:14:59.075: Se3/1 (sw 16) NameSet *Jul 22 20:14:59.075: Se3/1 (sw 16) FIBHWLnk Serial3/1(16) *Jul 22 20:14:59.075: Se3/1 (sw 16) SWIDBLnk Serial3/1(16) *Jul 22 20:14:59.075: Se3/1 (sw 16) FlagCha 0x6001 add p2p|input|first *Jul 22 20:14:59.075: Se3/1 (sw 16) FlagCha 0x6041 add auto_adj *Jul 22 20:14:59.075: Se3/1 (sw 16) Impared lc rea Queueing configuration *Jul 22 20:14:59.075: Se3/1 (sw 16) FlagCha 0x60C1 add puntLC *Jul 22 20:14:59.075: <empty> (hw 17) State down -> up *Jul 22 20:14:59.075: <empty> (hw 17) Create new *Jul 22 20:14:59.075: Se3/2 (hw 17) NameSet |
| Step 6 |
show
monitor
event-trace
cef
events
all
Use this command to display information about Cisco Express Forwarding events. For example: Example: Router# show monitor event-trace cef events all *Jul 13 17:38:27.999: SubSys ipv4fib_ios_def_cap init *Jul 13 17:38:27.999: SubSys ipv6fib_ios_def_cap init *Jul 13 17:38:27.999: Inst unknown -> RP *Jul 13 17:38:27.999: SubSys fib_ios_chain init *Jul 13 17:38:28.199: SubSys fib init *Jul 13 17:38:28.199: SubSys ipv4fib init *Jul 13 17:38:28.199: SubSys fib_ios init *Jul 13 17:38:28.199: SubSys fib_ios_if init *Jul 13 17:38:28.199: SubSys ipv4fib_ios init *Jul 13 17:38:28.199: Flag Common CEF enabled set to yes *Jul 13 17:38:28.199: Flag IPv4 CEF enabled set to yes *Jul 13 17:38:28.199: Flag IPv4 CEF switching enabled set to yes *Jul 13 17:38:28.199: GState CEF enabled *Jul 13 17:38:28.199: SubSys ipv6fib_ios init *Jul 13 17:38:28.199: SubSys ipv4fib_util init *Jul 13 17:38:28.199: SubSys ipv4fib_les init *Jul 13 17:38:34.059: Process Background created *Jul 13 17:38:34.059: Flag IPv4 CEF running set to yes *Jul 13 17:38:34.059: Process Background event loop enter *Jul 13 17:38:34.079: Flag IPv4 CEF switching running set to yes The output is in table format where the first column contains a time stamp, the second column lists the type of event, and the third column lists the detail for the event. For example, the Subsys event type is related to the initialization of a subset of Cisco Express Forwarding functionality. The "ipv4fib_ios_def_cap init" entry is the initialization of IPv4 Cisco Express Forwarding default capabilities. |
| Step 7 |
show
monitor
event-trace
cef
interface
latest
Use this command to display only the event trace messages generated since the last show monitor event-trace cef interfacecommand was entered. For example: Example: Router# show monitor event-trace cef interface latest *Jul 22 20:14:58.999: Et0/0 (hw 3) SWvecLES <unknown> (0x01096A3C) *Jul 22 20:14:58.999: Et0/1 (hw 4) SWvecLES <unknown> (0x01096A3C) *Jul 22 20:14:58.999: Et0/2 (hw 5) SWvecLES <unknown> (0x01096A3C) *Jul 22 20:14:58.999: Et0/3 (hw 6) SWvecLES <unknown> (0x01096A3C) . . . *Jul 22 20:14:59.075: <empty> (hw 3) State down -> up *Jul 22 20:14:59.075: <empty> (hw 3) Create new *Jul 22 20:14:59.075: Et0/0 (hw 3) NameSet *Jul 22 20:14:59.075: Et0/0 (hw 3) HWIDBLnk Ethernet0/0(3) *Jul 22 20:14:59.075: Et0/0 (hw 3) RCFlags None -> Fast *Jul 22 20:14:59.075: <empty> (sw 3) VRFLink IPv4:id0 - success *Jul 22 20:14:59.075: <empty> (sw 3) State deleted -> down *Jul 22 20:14:59.075: <empty> (sw 3) Create new *Jul 22 20:14:59.075: Et0/0 (sw 3) NameSet *Jul 22 20:14:59.075: Et0/0 (sw 3) FIBHWLnk Ethernet0/0(3) *Jul 22 20:14:59.075: Et0/0 (sw 3) SWIDBLnk Ethernet0/0(3) *Jul 22 20:14:59.075: Et0/0 (sw 3) FlagCha 0x6000 add input|first *Jul 22 20:14:59.075: Et0/0 (sw 3) State down -> up *Jul 22 20:14:59.075: <empty> (hw 4) State down -> up *Jul 22 20:14:59.075: <empty> (hw 4) Create new *Jul 22 20:14:59.075: Et0/1 (hw 4) NameSet *Jul 22 20:14:59.075: Et0/1 (hw 4) HWIDBLnk Ethernet0/1(4) *Jul 22 20:14:59.075: Et0/1 (hw 4) RCFlags None -> Fast *Jul 22 20:14:59.075: <empty> (sw 4) VRFLink IPv4:id0 - success *Jul 22 20:14:59.075: <empty> (sw 4) State deleted -> down *Jul 22 20:14:59.075: <empty> (sw 4) Create new *Jul 22 20:14:59.075: Et0/1 (sw 4) NameSet *Jul 22 20:14:59.075: Et0/1 (sw 4) FIBHWLnk Ethernet0/1(4) *Jul 22 20:14:59.075: Et0/1 (sw 4) SWIDBLnk Ethernet0/1(4) *Jul 22 20:14:59.075: Et0/1 (sw 4) FlagCha 0x6000 add input|first *Jul 22 20:14:59.075: Et0/1 (sw 4) State down -> up . . . |
| Step 8 |
show
monitor
event-trace
cef
ipv4
all
Use this command to display information about Cisco Express Forwarding IPv4 events. For example: Example:
Router# show monitor event-trace cef ipv4 all
*Jul 22 20:14:59.075: [Default] *.*.*.*/* Allocated FIB table
[OK]
*Jul 22 20:14:59.075: [Default] *.*.*.*/*'00 Add source Default table
[OK]
*Jul 22 20:14:59.075: [Default] 0.0.0.0/0'00 FIB add src DRH (ins)
[OK]
*Jul 22 20:14:59.075: [Default] *.*.*.*/*'00 New FIB table
[OK]
*Jul 22 20:15:02.927: [Default] *.*.*.*/*'00 FIB refresh start
[OK]
.
.
.
|
| Step 9 |
show
monitor
event-trace
cef
ipv6
parameters
Use this commands to display parameters configured for Cisco Express Forwarding IPv6 events. For example: Example: Router# show monitor event-trace cef ipv6 parameters Trace has 1000 entries Stacktrace is disabled by default Matching all events |
| Step 10 |
disable
Use this command to exit to user EXEC mode. For example: Example: Router# disable Router> |
Configuration Examples for the Display of CEF Event Trace Messages
- Example Customizing CEF Event Tracing
- Example Customizing CEF Event Tracing for IPv4 Events
- Example Customizing CEF Event Tracing for IPv6 Events
Example Customizing CEF Event Tracing
The following example shows how to enable event tracing for Cisco Express Forwarding and configure the buffer size to 2500 messages. The trace messages file is set to cef-dump in slot0 (flash memory).
configure terminal ! monitor event-trace cef events enable monitor event-trace cef dump-file slot0:cef-dump monitor event-trace cef events size 2500 exit The following example shows what happens when you try to enable event tracing for Cisco Express Forwarding events when it is already enabled: configure terminal ! monitor event-trace cef events enable 00:04:33: %EVENT_TRACE-6-ENABLE: Trace already enabled.
The following example shows the privileged EXEC commands that stop event tracing, clear the current contents of memory, and reenable the trace function for Cisco Express Forwarding events. This example assumes that the tracing function is configured and enabled on the networking device.
enable ! monitor event-trace cef events disable monitor event-trace cef events clear monitor event-trace cef events enable disable
Example Customizing CEF Event Tracing for IPv4 Events
The following example shows how to enable event tracing for Cisco Express Forwarding IPv4 events and configure the buffer size to 5000 messages:
configure terminal ! monitor event-trace cef ipv4 enable monitor event-trace cef ipv4 size 5000 exit The following example shows how to enable event tracing for events that match Cisco Express Forwarding IPv4 VRF vpn1: configure terminal ! monitor event-trace cef ipv4 enable monitor event-trace cef ipv4 vrf vpn1 exit
The following example shows the privileged EXEC commands to configure the continuous display of the latest Cisco Express Forwarding event trace entries for IPv4 events:
enable ! monitor event-trace cef ipv4 continuous disable
The following example shows how to stop the continuous display of the latest trace entries:
enable ! monitor event-trace cef ipv4 continuous cancel disable
Example Customizing CEF Event Tracing for IPv6 Events
The following example shows how to enable event tracing for Cisco Express Forwarding IPv6 events and configure the buffer size to 10000:
configure terminal ! monitor event-trace cef ipv6 enable monitor event-trace cef ipv6 size 10000 exit
Additional References
Related Documents
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Related Topic |
Document Title |
|---|---|
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Cisco IOS commands |
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Cisco Express Forwarding commands |
Cisco IOS IP Switching Command Reference |
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Overview of the Cisco Express Forwarding feature |
Cisco Express Forwarding Overview |
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Tasks for verifying basic Cisco Express Forwarding and distributed Cisco Express Forwarding operation |
Configuring Basic Cisco Express Forwarding for Improved Performance, Scalability, and Resiliency in Dynamic Networks |
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Tasks for enabling or disabling Cisco Express Forwarding or distributed Cisco Express Forwarding |
Enabling or Disabling Cisco Express Forwarding or Distributed Cisco Express Forwarding to Customize Switching and Forwarding for Dynamic Networks |
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Tasks for configuring load-balancing schemes for Cisco Express Forwarding |
Configuring a Load-Balancing Scheme for Cisco Express Forwarding Traffic |
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Tasks for configuring Cisco Express Forwarding consistency checkers |
Configuring Cisco Express Forwarding Consistency Checkers for Route Processors and Line Cards |
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Tasks for configuring epochs for Cisco Express Forwarding tables |
Configuring Epochs to Clear and Rebuild Cisco Express Forwarding and Adjacency Tables |
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Tasks for configuring and verifying Cisco Express Forwarding network accounting |
Configuring Cisco Express Forwarding Network Accounting |
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Tasks for customizing the display of recorded Cisco Express Forwarding events in Cisco IOS releases prior to Cisco IOS Releases 12.2(25)S, 12.2(33)SB, 12.2(33)SRA, 12.2(33)SXH, and 12.4(20)T |
Customizing the Display of Recorded Cisco Express Forwarding Events |
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Causes of common Cisco Express Forwarding-related error messages on platforms running distributed Cisco Express Forwarding switching (Cisco 7500 series routers and Cisco 12000 series Internet routers) and how to troubleshoot them |
Troubleshooting Cisco Express Forwarding-Related Error Messages |
Standards
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Standard |
Title |
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No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature. |
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MIBs
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MIB |
MIBs Link |
|---|---|
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No new or modified MIBs are supported by this feature, and support for existing MIBs has not been modified by this feature. |
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFCs
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RFC |
Title |
|---|---|
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No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature. |
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Technical Assistance
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Description |
Link |
|---|---|
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The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
Feature Information for the Display of CEF Event Trace Messages
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to . An account on Cisco.com is not required.|
Feature Name |
Releases |
Feature Configuration Information |
|---|---|---|
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This table is intentionally left blank because no features were introduced or modified in Cisco IOS Release 12.2(1) or later. This table will be updated when feature information is added to this module. |
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Glossary
adjacency --A relationship formed between selected neighboring routers and end nodes for the purpose of exchanging routing information. Adjacency is based upon the use of a common media segment by the routers and nodes involved.
Cisco Express Forwarding --A Layer 3 switching technology. Cisco Express Forwarding can also refer to central Cisco Express Forwarding mode, one of two modes of Cisco Express Forwarding operation. Cisco Express Forwarding enables a Route Processor to perform express forwarding. Distributed Cisco Express Forwarding is the other mode of Cisco Express Forwarding operation.
distributed Cisco Express Forwardin g--A mode of Cisco Express Forwarding operation in which line cards (such as Versatile Interface Processor (VIP) line cards) maintain identical copies of the forwarding information base (FIB) and adjacency tables. The line cards perform the express forwarding between port adapters; this relieves the Route Switch Processor of involvement in the switching operation.
FIB --forwarding information base. A component of Cisco Express Forwarding that is conceptually similar to a routing table or information base. The router uses the FIB lookup table to make destination-based switching decisions during Cisco Express Forwarding operation. The router maintains a mirror image of the forwarding information in an IP routing table.
line card --A general term for an interface processor that can be used in various Cisco products. For example, a Versatile Interface Processor (VIP) is a line card for the Cisco 7500 series router.
prefix --The network address portion of an IP address. A prefix is specified by a network and mask and is generally represented in the format network/mask. The mask indicates which bits are the network bits. For example, 1.0.0.0/16 means that the first 16 bits of the IP address are masked, making them the network bits. The remaining bits are the host bits. In this example, the network number is 10.0.
VPN --Virtual Private Network. The result of a router configuration that enables IP traffic to use tunneling to travel securely over a public TCP/IP network.
VRF --A Virtual Private Network (VPN) routing/forwarding instance. A VRF consists of an IP routing table, a derived forwarding table, a set of interfaces that use the forwarding table, and a set of rules and routing protocols that determine what goes into the forwarding table. In general, a VRF includes the routing information that defines a customer VPN site that is attached to a PE router.