- 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
- Finding Feature Information
- Information About CEF
- Introduction of CEF Enhancements
- CEF Enhancements Described
- Removal of Support for IPv4 Fast Switching
- CEF Command Changes
- CEF show Command Output Changes
- show ip cef summary
- show ipv6 cef summary
- show ip cef internal
- show ipv6 cef internal
- show ip cef detail
- show ipv6 cef detail
- show ip cef internal
- show ipv6 cef internal
- show ip cef
- show ip cef exact-route detail
- show ip cef exact-route
- show ip cef adjacency
- show adjacency summary
- show adjacency detail
- show adjacency internal
- show cef state
- show cef timers
- show ip cef epoch
- show ipv6 cef epoch
- show ip cef unresolved detail
- show ipv6 cef unresolved detail
- show ipv6 cef non-recursive
- New Commands for the CEF Feature
- Unchanged CEF show Commands
- Additional References
- Feature Information for CEF Enhancements
- Glossary
CEF Enhancements
The purpose of this document is to describe the changes based on the Cisco Express Forwarding infrastructure scalability enhancements that have been implemented to adapt to the evolution of the Internet and to support new platforms and features. The changes are the removal of IP fast switching and the introduction of command line interface (CLI) modifications.
This document lists Cisco Express Forwarding CLI commands that are removed, replaced, changed, and new. To help you transition to the new CLI format, the document illustrates the output for new commands and changed commands.
Enhancements to Cisco Express Forwarding enable it to operate with the Multiprotocol Label Switching (MPLS) Forwarding Infrastructure (MFI) and guarantee consistency across Cisco IOS release trains. Cisco Express Forwarding infrastructure changes were introduced and implemented in the Cisco IOS 12.2(25)S-based releases and were added for T releases in Cisco IOS Release 12.4(20)T.
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
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.
Information About CEF
This document presents the following topics to explain the changes you will find with the implementation of the Cisco Express Forwarding enhancements. This information should be helpful as you transition to Cisco IOS software that includes the Cisco Express Forwarding and MFI enhancements.
The fifth and sixth topics provide information about the CLI changes implemented as part of the Cisco Express Forwarding enhancements. In each section, the commands that are changed are listed, followed by an explanation of how they are changed. Sample command output is included in sections to compare "before" and "after" output information and to provide new output information.
The information about the commands is presented in the following order:
- Removed or existing, but unsupported, commands
- Commands with modified output
- New commands created for output consistency
- Related commands with unchanged output
- Introduction of CEF Enhancements
- CEF Enhancements Described
- Removal of Support for IPv4 Fast Switching
- CEF Command Changes
- CEF show Command Output Changes
- New Commands for the CEF Feature
- Unchanged CEF show Commands
Introduction of CEF Enhancements
Cisco Express Forwarding is at the heart of switching in every router. Improvements have been made to the Cisco Express Forwarding infrastructure to enhance and scale switching. Cisco Express Forwarding enhancements were introduced in Cisco IOS Release 12.2(25)S and first adopted by Cisco IOS 12.2(25)S-based releases. In Cisco IOS Release 12.4(20)T, the Cisco Express Forwarding enhancements were added for Cisco IOS 12.4(20)T releases and later T-based releases.
The table below lists the Cisco IOS releases and platforms that support the Cisco Express Forwarding enhancements and the changes described in this document.
| Table 1 | Cisco IOS Releases and Platforms That Support Cisco Express Forwarding Enhancements |
| Cisco IOS Release |
Platforms Supported |
|---|---|
| 12.2(25)SE |
Catalyst 2970 series switches Catalyst 3500 series switches Catalyst 3750 series switches |
| 12.2(25)SG |
Catalyst 4500 series Switches |
| 12.2(28)SB |
Cisco 7200 series routers Cisco 7301 series routers Cisco 7304 series routers Cisco 10000 series routers |
| 12.2(33)SRA |
Cisco 7600 series routers |
| 12.2(33)SXH |
Catalyst 6500 series switches |
| 12.4(20)T |
Cisco 800 series routers Cisco 1700 series routers Cisco 1800 series routers Cisco 2600 series routers Cisco 2800 series routers Cisco 3200 series routers Cisco 3600 series routers Cisco 3700 series routers Cisco 3800 series routers Cisco 7200 series routers Cisco 7400 series routers Cisco 8850 series routers Cisco AS5000 series universal gateways |
CEF Enhancements Described
Cisco IOS Release 12.4(20)T incorporates the following Cisco Express Forwarding infrastructure changes:
- Cisco Express Forwarding Scalability and Selective Rewrite (CSSR) for enhanced scalable, distributed Layer 3 switching
- Enhanced Multiprotocol Label Switching (MPLS) Forwarding Infrastructure (MFI)
For information on MFI enhancements, see MPLS Infrastructure Changes: Introduction of MFI and Removal of MPLS LSC and LC-ATM Features.
The Cisco Express Forwarding infrastructure changes provide the following:
- Simplified fast switching path decisions for both IPv4 and IPv6 traffic, which improve performance and provide more CPU cycles for other Cisco IOS services
- Enhanced scalability to support large numbers of the following:
- Improved manageability of the following:
No new features are introduced in Cisco IOS Release 12.4(20)T. However, some features that previously shipped with a Cisco IOS 12.2(25)S-based release are new to the Cisco IOS 12.4T release.
 Note |
CSSR and MFI enhancements in Cisco IOS Release 12.4(20)T might result in changed performance characteristics in your network. We suggest that you test configurations before upgrading to this software. |
Removal of Support for IPv4 Fast Switching
IPv4 fast switching is removed with the implementation of the Cisco Express Forwarding infrastructure enhancements for Cisco IOS 12.2(25)S-based releases and Cisco IOS Release 12.4(20)T. For these and later Cisco IOS releases, switching path are Cisco Express Forwarding switched or process switched. This makes the switching decision easier for future development of software features.
Note |
Starting with the implementation of the Cisco Express Forwarding enhancements and the removal of IPv4 fast switching, components that do not support Cisco Express Forwarding will work only in process switched mode. |
CEF Command Changes
The following commands are obsolete and have been removed from Cisco IOS software with the present Cisco Express Forwarding enhancements:
- show ip cef inconsistency records
- show ip cef inconsistency now
- show ip cef inconsistency now detail
The table below lists the commands that replace the removed commands.
| Table 2 | Removed Cisco Express Forwarding Commands--Cisco Express Forwarding |
| Command Before Cisco Express Forwarding Enhancements |
Replacement Command After Cisco Express Forwarding Enhancements |
|---|---|
| ip cef table adjacency-prefix |
-- |
| ip cef table resolution-timer |
-- |
| show ip cef inconsistency records |
test cef table consistency |
| show ip cef inconsistency now |
test cef table consistency |
| show ip cef inconsistency now detail |
test cef table consistency detail |
The following commands still exist, but are no longer supported in Cisco IOS software:
The table below lists commands that still exist, but are no longer supported, and the commands that replaces the unsupported commands. You should start using the replacement commands.
| Table 3 | Replaced Cisco Express Forwarding Commands--Cisco Express Forwarding Feature |
| Command Before Cisco Express Forwarding Enhancements |
Replacement Command After Cisco Express Forwarding Enhancements |
|---|---|
| ip cef event -log |
monitor event-log cef event |
| ip cef interface event-log |
monitor event-log cef interface |
| ip cef table event-log |
monitor event-log cef ipv4 |
| ip cef table consistency-check |
cef table consistency-check |
| ip cef loadinfo |
cef table output-chain |
| show cef events |
show monitor event-trace cef events all |
| show cef drop |
show {ip | ipv6} cef switching statistics[feature]1 |
| show cef not-cef-switched |
show {ip| ipv6} cef switching statistics [feature] |
CEF show Command Output Changes
This section describes the CLI command output changes introduced with the Cisco Express Forwarding feature. In some commands the output format is changed. In other commands, pieces of information are added or removed from the output. The output of the following commands is changed with this feature:
- show ip cef summary
- show ipv6 cef summary
- show ip cef internal
- show ipv6 cef internal
- show ip cef detail
- show ipv6 cef detail
- show ip cef internal
- show ipv6 cef internal
- show ip cef
- show ip cef exact-route detail
- show ip cef exact-route
- show ip cef adjacency
- show adjacency summary
- show adjacency detail
- show adjacency internal
- show cef state
- show cef timers
- show ip cef epoch
- show ipv6 cef epoch
- show ip cef unresolved detail
- show ipv6 cef unresolved detail
- show ipv6 cef non-recursive
For a full description of these commands, see the Cisco IOS IP Switching Command Reference and the Cisco IOS IPv6 Command Reference.
- show ip cef summary
- show ipv6 cef summary
- show ip cef internal
- show ipv6 cef internal
- show ip cef detail
- show ipv6 cef detail
- show ip cef internal
- show ipv6 cef internal
- show ip cef
- show ip cef exact-route detail
- show ip cef exact-route
- show ip cef adjacency
- show adjacency summary
- show adjacency detail
- show adjacency internal
- show cef state
- show cef timers
- show ip cef epoch
- show ipv6 cef epoch
- show ip cef unresolved detail
- show ipv6 cef unresolved detail
- show ipv6 cef non-recursive
show ip cef summary
This feature provides the following changes to the output of the show ip cef summary command:
- IPv4 and IPv6 are separately addressed.
- Figures related to adjacencies are moved to the show adjacency summarycommand (see the show adjacency summary).
- Mtrie data structure descriptions are moved to a new command, the show ip cef tree command (see the New Commands for the CEF Feature).
The table below compares the show ip cef summary command output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 4 | show ip cef summary Command Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show ip cef summary IP CEF with switching (Table Version 32), flags=0x0 26 routes, 0 reresolve, 0 unresolved (0 old, 0 new), peak 2 26 leaves, 19 nodes, 23400 bytes, 53 inserts, 27 invalidations 0 load sharing elements, 0 bytes, 0 references universal per-destination load sharing algorithm, id DF940F94 3(0) CEF resets, 0 revisions of existing leaves Resolution Timer: Exponential (currently 1s, peak 1s) 0 in-place/0 aborted modifications refcounts: 1342 leaf, 1321 node Table epoch: 0 (26 entries at this epoch) Adjacency Table has 4 adjacencies 2 IPv4 adjacencies 2 IPv6 adjacencies |
Router# show ip cef summary IPv4 CEF is enabled and running VRF Default: 22 prefixes (22/0 fwd/non-fwd) Table id 0 Database epoch: 0 (22 entries at this epoch) |
show ipv6 cef summary
This feature provides the following change to the output of the show ipv6 cef summary command:
- Output is reformatted (information provided is similar to what was provided before the Cisco Express Forwarding enhancement.)
The table below compares the show ipv6 cef summary command output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 5 | show ipv6 cef summary Command Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show ipv6 cef summary IPv6 CEF is enabled and running Slow processing intvl = 1 seconds backoff level current/max 0/0 0 unresolved prefixes, 0 requiring adjacency update IPv6 CEF default table 19 prefixes |
Router# show ipv6 cef summary
IPv6 CEF is enabled and running
VRF Default:
20 prefixes (20/0 fwd/non-fwd)
Table id 0
Database epoch: 0 (20 entries at this epoch) |
show ip cef internal
This feature provides the following changes to the output of the show ip cef internal command:
- IPv4 and IPv6 are separately addressed.
- Mtrie data structure descriptions are moved to a new command, the show ip cef tree command (see the New Commands for the CEF Feature).
- Troubleshooting is made easier with the addition of references to internal structure pointers.
- The concept of output chain (chain of output features) is introduced.
The table below compares the show ip cef internalcommand output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 6 | show ip cef internal Command Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show ip cef internal
IP CEF with switching (Table Version 32), flags=0x0
26 routes, 0 reresolve, 0 unresolved (0 old, 0 new), peak 2
26 leaves, 19 nodes, 23400 bytes, 53 inserts, 27 invalidations
0 load sharing elements, 0 bytes, 0 references
universal per-destination load sharing algorithm, id DF940F94
3(0) CEF resets, 0 revisions of existing leaves
Resolution Timer: Exponential (currently 1s, peak 1s)
0 in-place/0 aborted modifications
refcounts: 1342 leaf, 1321 node
Table epoch: 0 (26 entries at this epoch)
Adjacency Table has 3 adjacencies
1 IPv4 adjacency
2 IPv6 adjacencies
0.0.0.0/32, version 0, epoch 0, receive
10.10.1.1/32, version 22, epoch 0, cached adjacency 172.17.24.1 (0x629E1B60)
0 packets, 0 bytes
via 172.17.24.1, FastEthernet0/1, 0 dependencies
next hop 172.17.24.1, FastEthernet0/1
valid cached adjacency (0x629E1B60)
|
Router# show ip cef internal
IPv4 CEF is enabled and running
VRF Default:
22 prefixes (22/0 fwd/non-fwd)
Table id 0
Database epoch: 0 (22 entries at this epoch)
0.0.0.0/32, epoch 0, flags receive, refcount 4
sources: Spc
feature space:
MFI: path extension list empty
subblocks:
Special source: receive
ifnums: (none)
path 633AA3DC, path list 633A79D0, share 1, type receive
path_list contains no resolved destination(s). HW IPv4 notified.
receive
output chain: receive (11)
10.10.1.1/32, epoch 0, RIB, refcount 4
sources: RIB
feature space:
MFI: path extension list empty
IPRM: 0x00038000
IP adj out of POS1/0 635BB2A0
ifnums: (none)
path 633A9504, path list 633A6FB8, share 1, type attached nexthop
path_list contains at least one resolved destination(s). HW IPv4 notified.
nexthop 172.17.13.1 POS1/0, adjacency IP adj out of POS1/0 635BB2A0
output chain: IP adj out of POS1/0 635BB2A0 |
show ipv6 cef internal
This feature provides the following changes to the output of the show ipv6 cef internal command:
- More references to pointers are added.
- The concept of output chain (chain of output features) is introduced.
The previous version of the command output is very similar to the output of the command after the Cisco Express Forwarding enhancements.
The table below compares the show ipv6 cef internalcommand output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 7 | show ipv6 cef internal Command Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show ipv6 cef internal
IPv6 CEF is enabled and running
Slow processing intvl = 1 seconds backoff level current/max 0/0
0 unresolved prefixes, 0 requiring adjacency update
IPv6 CEF default table
19 prefixes tableid 0
table version 37
root 63038970
2001:1:12::/64 RIBfib
Using cached adjacency 0x629E1CE0
path list pointer 62A2C310
1 path -
Nexthop path_pointer 62A297B0 traffic share 1 path_list pointer 62A2C310
nexthop FE80::2D0:1FF:FEE4:6800 FastEthernet0/1
next_hop_len 0 adjacency pointer 629E1CE0
refcount 10
no loadinfo
|
Router# show ipv6 cef internal IPv6 CEF is enabled and running VRF Default: 20 prefixes (20/0 fwd/non-fwd) Table id 0 Database epoch: 0 (20 entries at this epoch) 2001:1:12::/64, epoch 0, RIB, refcount 3 sources: RIB feature space: MFI: path extension list empty IPRM: 0x00038000 IPV6 adj out of POS1/0 635BAFE0 ifnums: (none) path 633A9A18, path list 633A732C, share 1, type attached nexthop path_list contains at least one resolved destination(s). HW IPv6 notified. nexthop FE80::205:DCFF:FE26:4800 POS1/0, adjacency IPV6 adj out of POS1/0 635BAFE0 output chain: IPV6 adj out of POS1/0 635BAFE0 |
show ip cef detail
This feature provides the following changes to the output of the show ip cef detail command:
- IPv4 and IPv6 are now separately addressed.
- Mtrie data structure descriptions are moved to a new command, the show ip cef tree command (see the New Commands for the CEF Feature).
- The per-prefix output is reformatted (however, the information provided is the same).
- The table below compares the show ip cef detailcommand output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 8 | show ip cef detail Command Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show ip cef detail
IP CEF with switching (Table Version 32), flags=0x0
26 routes, 0 reresolve, 0 unresolved (0 old, 0 new), peak 2
26 leaves, 19 nodes, 23400 bytes, 53 inserts, 27 invalidations
0 load sharing elements, 0 bytes, 0 references
universal per-destination load sharing algorithm, id DF940F94
3(0) CEF resets, 0 revisions of existing leaves
Resolution Timer: Exponential (currently 1s, peak 1s)
0 in-place/0 aborted modifications
refcounts: 1342 leaf, 1321 node
Table epoch: 0 (26 entries at this epoch)
Adjacency Table has 3 adjacencies
1 IPv4 adjacency
2 IPv6 adjacencies
0.0.0.0/32, version 0, epoch 0, receive
10.10.1.1/32, version 22, epoch 0, cached adjacency 172.17.24.1
0 packets, 0 bytes
via 172.17.24.1, FastEthernet0/1, 0 dependencies
next hop 172.17.24.1, FastEthernet0/1
valid cached adjacency |
Router# show ip cef detail
IPv4 CEF is enabled and running
VRF Default:
22 prefixes (22/0 fwd/non-fwd)
Table id 0
Database epoch: 0 (22 entries at this epoch)
0.0.0.0/32, epoch 0, flags receive
Special source: receive
receive
10.10.1.1/32, epoch 0
nexthop 172.17.13.1 POS1/0
10.10.1.2/32, epoch 0
nexthop 172.17.13.1 POS1/0
10.20.12.0/24, epoch 0
nexthop 172.17.13.1 POS1/0
10.60.17.0/24, epoch 0, flags attached, connected
attached to FastEthernet0/0
10.60.17.0/32, epoch 0, flags receive
receive
10.60.17.251/32, epoch 0, flags receive
receive
|
show ipv6 cef detail
This feature provides the following change to the output of the show ipv6 cef detail command:
- Output is reformatted (the information provided is the same as before the Cisco Express Forwarding enhancements).
The table below compares the show ipv6 cef detailcommand output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 9 | show ipv6 cef detail Command Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show ipv6 cef detail
IPv6 CEF is enabled and running
Slow processing intvl = 1 seconds backoff level current/max 0/0
0 unresolved prefixes, 0 requiring adjacency update
IPv6 CEF default table
19 prefixes
2001:1:12::/64 RIBfib
nexthop FE80::2D0:1FF:FEE4:6800 FastEthernet0/1
2001:2:13::/64 RIBfib
nexthop FE80::2D0:1FF:FEE4:6800 FastEthernet0/1
2001:2:22::/64 RIBfib
nexthop FE80::2D0:1FF:FEE4:6800 FastEthernet0/1
2001:2:24::2/128 Receive, RIBfib
Receive
2001:2:24::/64 Attached, Connected, RIBfib attached to FastEthernet0/1 |
Router# show ipv6 cef detail
IPv6 CEF is enabled and running
VRF Default:
20 prefixes (20/0 fwd/non-fwd)
Table id 0
Database epoch: 0 (20 entries at this epoch)
2001:1:12::/64, epoch 0
nexthop FE80::205:DCFF:FE26:4800 POS1/0
2001:2:13::/64, epoch 0, flags attached, connected
attached to POS1/0
2001:2:13::2/128, epoch 0, flags receive
|
show ip cef internal
This feature provides the following changes to the output of the show ip cef prefix internal command:
- Troubleshooting is made easier with the addition of references to internal structure pointers.
- The concept of output chain (chain of output features) is introduced.
The table below compares the show ip cef prefix internal command output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 10 | show ip cef prefix internalCommand Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show ip cef 10.20.12.0/24 internal 10.20.12.0/24, version 17, epoch 0, cached adjacency 172.17.24.1 (0x629E1B60) 0 packets, 0 bytes via 172.17.24.1, FastEthernet0/1, 0 dependencies next hop 172.17.24.1, FastEthernet0/1 valid cached adjacency (0x629E1B60) |
Router# show ip cef 172.16.1.0/24 internal
172.16.1.0/24, epoch 0, RIB, refcount 5
sources: RIB
feature space:
MFI: path extension list empty
IPRM: 0x00038000
IP adj out of POS1/0 635BB2A0
path 633A9504, path list 633A6FB8, share 1, type attached nexthop, for IPv4
ifnums: (none)
path_list contains at least one resolved destination(s). HW IPv4 notified.
nexthop 172.17.13.1 POS1/0, adjacency IP adj out of POS1/0 635BB2A0
output chain: IP adj out of POS1/0 635BB2A0 |
show ipv6 cef internal
This feature provides the following changes to the output of the show ipv6 cef prefix internal command:
- More references to structure pointers are added.
- The concept of output chain (chain of output features) is introduced.
The previous version of the command output is very similar to the output in the command after the Cisco Express Forwarding enhancements.
The table below compares the show ipv6 cef prefix internal command output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 11 | show ipv6 cef prefix internal Command Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show ipv6 cef 2001:2:25::/64 internal
2001:2:25::/64 RIBfib
Using cached adjacency 0x629E1CE0
path list pointer 62A2C310
1 path -
Nexthop path_pointer 62A297B0 traffic share 1 path_list pointer 62A2C310
nexthop FE80::2D0:1FF:FEE4:6800 FastEthernet0/1
next_hop_len 0 adjacency pointer 629E1CE0
refcount 10
no loadinfo |
Router# show ipv6 cef 2001:2:25::/64 internal
2001:2:25::/64, epoch 0, RIB, refcount 4
sources: RIB
feature space:
MFI: path extension list empty
IPRM: 0x00038000
IPV6 adj out of POS1/0 635BAFE0
path 633A9568, path list 633A6FFC, share 1, type attached nexthop, for IPv6
ifnums: (none)
path_list contains at least one resolved destination(s). HW IPv6 notified.
nexthop FE80::205:DCFF:FE26:4800 POS1/0, adjacency IPV6 adj out of POS1/0 635BAFE0 |
show ip cef
This feature provides the following changes to the output of the show ip cef prefix command:
- Output is reformatted; the key information provided is similar to the command output provided before the Cisco Express Forwarding enhancements.
- Adjacency information is moved to the show adjacency prefix detail command (see the New Commands for the CEF Feature).
The table below compares the show ip cef prefixcommand output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 12 | show ip cef prefix Command Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show ip cef 10.20.12.0/24
10.20.12.0/24, version 17, epoch 0, cached adjacency 172.17.24.1
0 packets, 0 bytes
via 172.17.24.1, FastEthernet0/1, 0 dependencies
next hop 172.17.24.1, FastEthernet0/1
valid cached adjacency |
Router# show ip cef 172.16.1.0/24
172.16.1.0/24
nexthop 172.17.13.1 POS1/0
|
Note |
The command output of the show ipv6 prefix command is the same after the Cisco Express Forwarding enhancement changes as it was before the changes. |
show ip cef exact-route detail
This feature provides the following change to the output of the show ip cef exact-route source destination detail command:
- Output is reformatted (the information provided is the same as the information provided before the Cisco Express Forwarding enhancements).
The table below compares the command output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 13 | show ip cef exact-route source destination detail Command Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show ip cef exact-route 172.16.1.1 172.16.1.5 detail
172.16.1.1 -> 172.16.1.5 : FastEthernet0/1 (next hop 172.17.24.1) |
Router# show ip cef exact-route 172.16.1.3 172.16.1.2 detail
172.16.1.3 -> 172.16.1.2 => IP adj out of FastEthernet0/1, addr 172.17.25.1 |
show ip cef exact-route
This feature provides the following change to the output of the show ip cef exact-route source destinationcommand:
- Output is reformatted (the information provided is the same as the information provided before the Cisco Express Forwarding enhancements).
The table below compares the show ip cef exact-route source destinationcommand output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 14 | show ip cef exact-route source destination Command Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show ip cef exact-route 172.16.1.1 172.16.1.5
172.16.1.1 -> 172.16.1.5 : FastEthernet0/1 (next hop 172.17.24.1) |
Router# show ip cef exact-route 172.16.1.3 172.16.1.2
172.16.1.3 -> 172.16.1.2 => IP adj out of FastEthernet0/1, addr 172.17.25.1 |
show ip cef adjacency
This feature provides the following change to the output of the show ip cef adjacency interface next-hopcommand:
- Output is reformatted (the information provided is the same as the information provided before the Cisco Express Forwarding enhancements).
The table below compares the show ip cef adjacency interface next-hopcommand output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 15 | show ip cef adjacency interface next-hopCommand Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show ip cef adjacency FastEthernet0/1 172.17.24.1
Prefix Next Hop Interface
10.10.1.1/32 172.17.24.1 FastEthernet0/1
10.10.1.2/32 172.17.24.1 FastEthernet0/1
10.20.12.0/24 172.17.24.1 FastEthernet0/1 |
Router# show ip cef adjacency FastEthernet0/1 172.17.22.1
10.10.1.2/32
nexthop 172.17.22.1 FastEthernet0/1
10.20.12.0/24
nexthop 172.17.22.1 FastEthernet0/1 |
show adjacency summary
This feature provides the following change to the output of the show adjacency summary command:
- The new output provides a detailed description of the database, high availability information, and epoch concept information.
- The per-protocol and interface summary table is moved to the show adjacency linkcommand (see the New Commands for the CEF Feature).
The table below compares the show adjacency summary command output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 16 | show adjacency summary Command Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show adjacency summary
Adjacency Table has 6 adjacencies
4 IPv4 adjacencies
2 IPv6 adjacencies
Table epoch: 0 (6 entries at this epoch)
Interface IPv4 Adjacencies IPv6 Adjacencies
FastEthernet0/1 1 1
FastEthernet0/0 2 0
FastEthernet1/1 1 1 |
Router# show adjacency summary
Adjacency table has 9 adjacencies:
each adjacency consumes 348 bytes (0 bytes platform extension)
7 complete adjacencies
2 incomplete adjacencies
4 adjacencies of linktype IP
4 complete adjacencies of linktype IP
0 incomplete adjacencies of linktype IP
0 adjacencies with fixups of linktype IP
4 adjacencies with IP redirect of linktype IP
4 adjacencies of linktype IPV6
2 complete adjacencies of linktype IPV6
2 incomplete adjacencies of linktype IPV6
1 adjacency of linktype TAG
1 complete adjacency of linktype TAG
0 incomplete adjacencies of linktype TAG
Adjacency database high availability:
Database epoch: 0 (9 entries at this epoch)
Adjacency manager summary event processing:
Summary events epoch is 3
Summary events queue contains 0 events (high water mark 7 events) |
show adjacency detail
This feature provides the following change to the output of the show adjacency detail command:
- Output is reformatted (the information provided is the same as the information provided before the Cisco Express Forwarding enhancements).
The table below compares the show adjacency detail command output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 17 | show adjacency detailCommand Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show adjacency detail
Protocol Interface Address
IP FastEthernet1/1 20.0.0.2(5)
4 packets, 456 bytes
003085641F11
00055F26F81D0800
ARP 01:47:23
Epoch: 0
IPV6 FastEthernet1/1 2011:41::2(5)
0 packets, 0 bytes
003085641F11
00055F26F81D86DD
IPv6 ND never
Epoch: 0
|
Router# show adjacency detail
Protocol Interface Address
IP FastEthernet0/1 172.17.22.1(16)
0 packets, 0 bytes
epoch 0
sourced in sev-epoch 3
Encap length 14
00D001E4680000055FAF2C060800
ARP
IPV6 FastEthernet0/1 2001:2:22::1(6)
0 packets, 0 bytes
epoch 0
sourced in sev-epoch 3
Encap length 14
00D001E4680000055FAF2C0686DD
IPv6 ND |
show adjacency internal
This feature provides the following changes to the output of the show adjacency internal command:
- Output is reformatted.
- An output chain of features was added. Otherwise, the information provided is the same as the information provided before the Cisco Express Forwarding enhancements.
The table below compares the show adjacency internalcommand output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 18 | show adjacency internal Command Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show adjacency internal
Protocol Interface Address
IP FastEthernet1/1 20.0.0.2(5)
4 packets, 456 bytes
003085641F11
00055F26F81D0800
ARP 01:32:30
Epoch: 0
Fast adjacency enabled
IP redirect enabled
IP mtu 1500 (0x0)
Fixup disabled
Adjacency pointer 0x629E16E0, refCount 5
Adjacency flags 0x000000
Connection Id 0x000000
Bucket 22
IPV6 FastEthernet0/1 FE80::2D0:1FF:FEE4:6800(13)
0 packets, 0 bytes
00D001E46800
00055F26F80686DD
IPv6 ND never
Epoch: 0
Fast adjacency enabled
IPv6 redirect enabled
IPv6 mtu 1500 (0x0)
Fixup disabled
Adjacency pointer 0x629E1CE0, refCount 13
Adjacency flags 0x000000
Connection Id 0x000000 Bucket 32 |
Router# show adjacency internal
Protocol Interface Address
IP FastEthernet0/0 10.60.17.2(6)
0 packets, 0 bytes
epoch 0
sourced in sev-epoch 3
Encap length 14
00000C386D8800055FAF2C080800
ARP
Fast adjacency enabled [OK]
L3 mtu 1500
Flags (0x100E)
Fixup disabled
HWIDB/IDB pointers 0x63148358/0x63148FD8
IP redirect enabled
Switching vector: IPv4 no fixup adj oce
Adjacency pointer 0x636F31A0
Next-hop 172.17.13.1 ...
IPV6 FastEthernet0/1 2001:2:22::1(6)
0 packets, 0 bytes
epoch 0
sourced in sev-epoch 3
Encap length 14
00D001E4680000055FAF2C0686DD
IPv6 ND
Fast adjacency enabled [OK]
L3 mtu 1500
Flags (0x100E)
Fixup disabled
HWIDB/IDB pointers 0x6313AD40/0x6313B9C0
IP redirect enabled
Switching vector: IPv6 adjacency oce
Adjacency pointer 0x531C738
Next-hop FE80::A8BB:FE00:6500 ... |
show cef state
This feature provides the following changes to the output of the show cef statecommand:
- New output is more concise.
- Load sharing anti-polarization ID is added to the command output.
- The show cef statecommand adds a new capabilities keyword. Capability details now display with the new keyword.
The table below compares the show cef statecommand output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 19 | show cef state Command Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show cef state
CEF Status [RP]
CEF enabled/running
dCEF disabled/not running
CEF switching enabled/running
CEF default capabilities:
Always CEF switching: no
Always dCEF switching: no
Default CEF switching: yes
Default dCEF switching: no
Drop multicast packets: no
OK to punt packets: yes
NVGEN CEF state: no
fastsend() used: yes
CEF NSF capable: no
RPR+/SSO standby capable: no
IPC delayed func on SSO: no
FIB auto repair supported: yes
LCs not running at init time: no
Hardware forwarding supported: no
Hardware forwarding in use: no
Load-sharing pr. packet supported: yes |
Router# show cef state CEF Status: RP instance common CEF enabled IPv4 CEF Status: CEF enabled/running dCEF disabled/not running CEF switching enabled/running universal per-destination load sharing algorithm, id A189DD49 IPv6 CEF Status: CEF enabled/running dCEF disabled/not running original per-destination load sharing algorithm, id A189DD49 Router# show cef state capabilities CEF Capabilities: Supported address families: IPv4 IPv6 Active address families: IPv4 IPv6 Distributed Platform: no Warm or Hot Standby supported: no CEF NSF capable: no IPC delayed func on SSO: no Hardware forwarding: no Checker auto-repair supported: yes Crashdump on memory failure: no Support load-sharing alg config: yes Blocking STANDBY_HOT until synced: no IPv4 CEF Capabilities: Default CEF switching: yes Always FIB switching: no Default dCEF switching: no Always dCEF switching: no Drop multicast packets: no OK to punt packets: yes NVGEN CEF state: yes fastsend() used: yes Support per packet load sharing: yes Support L4 ports in load sharing: yes Multicast (*,G) groups in CEF: no Install local entries from RIB: no |
| |
IPv6 CEF Capabilities:2 Default CEF switching: yes Always FIB switching: no Default dCEF switching: no Always dFIB switching: no Drop multicast packets: no OK to punt packets: yes NVGEN CEF state: yes fastsend() used: yes L4 ports in load balancing support: yes |
show cef timers
This feature provides the following change to the output of the show cef timerscommand:
The table below compares the show cef timerscommand output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 20 | show cef timersCommand Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show cef timers
CEF background process
Expiration Type
| 0.740 (parent)
| 0.740 ARP throttle
| 0.908 adjacency update hwidb
| 0.908 slow resolution
| 8.572 <unknown:6240E510/0>
CEF FIB scanner process
Expiration Type
| 5.764 (parent)
| 5.764 checker scan-rib
| 6.340 checker scan-sw-hw
| 49.588 checker scan-hw-sw |
Router# show cef timers
CEF background process
Expiration Type
| 13.248 (parent)
| 13.248 FIB checkers: IPv4 scan-rib-ios scanner
| 13.248 FIB checkers: IPv4 scan-ios-rib scanner
| 13.248 FIB checkers: IPv6 scan-ios-rib scanner
Platform counter polling is not enabled
IPv4 CEF background process
Expiration Type
| 0.600 (parent)
| 0.600 ARP throttle
| 0.600 adjacency update hwidb |
show ip cef epoch
This feature provides the following change to the output of the show ip cef epochcommand:
The table below compares the show ip cef epochcommand output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 21 | show ip cef epochCommand Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show ip cef epoch
CEF epoch information:
Table: Default
Table epoch: 0 (33 entries at this epoch)
Adjacency table Table epoch: 0 (7 entries at this epoch) |
Router# show ip cef epoch
Table: Default
Database epoch: 0 (24 entries at this epoch)
|
show ipv6 cef epoch
This feature provides the following change to the output of the show ipv6 cef epochcommand:
The table below compares the show ipv6 cef epochcommand output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 22 | show ipv6 cef epochCommand Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show ipv6 cef epoch
CEF epoch information:
Table: Default
Table epoch: 1 (2 entries at this epoch)
Adjacency table
Table epoch: 0 (1 entries at this epoch) |
Router# show ipv6 cef epoch
Table: Default
Database epoch: 1 (2 entries at this epoch)
|
show ip cef unresolved detail
This feature provides the following changes to the output of the show ip cef unresolved detailcommand:
- The new command output lists only unresolved prefixes.
- IPv4 and IPv6 are now separately addressed.
- Figures related to adjacencies are moved to the show adjacency summarycommand (see the show adjacency summary).
- Mtrie data structure descriptions are moved to a new command, the show ip cef treecommand (see the New Commands for the CEF Feature).
- Nothing is displayed if no unresolved adjacencies exist.
The table below compares the show ip cef unresolved detailcommand output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 23 | show ip cef unresolved detail Command Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show ip cef unresolved detail
IP CEF with switching (Table Version 59), flags=0x0
34 routes, 0 reresolve, 0 unresolved (0 old, 0 new), peak 2
34 leaves, 22 nodes, 27640 bytes, 80 inserts, 46 invalidations
0 load sharing elements, 0 bytes, 0 references
universal per-destination load sharing algorithm, id DF940F94
3(0) CEF resets, 0 revisions of existing leaves
Resolution Timer: Exponential (currently 1s, peak 1s)
0 in-place/0 aborted modifications
refcounts: 5933 leaf, 5888 node
Table epoch: 0 (34 entries at this epoch)
Adjacency Table has 7 adjacencies
4 IPv4 adjacencies
3 IPv6 adjacencies |
Router# show ip cef unresolved detail
IPv4 CEF is enabled and running
VRF Default
25 prefixes (25/0 fwd/non-fwd)
Table id 0x0
Database epoch: 0 (25 entries at this epoch)
101.1.1.1/32, epoch 0, flags rib only nolabel, rib defined all labels
recursive via 102.2.2.2, unresolved
|
show ipv6 cef unresolved detail
This feature provides the following changes to the output of the show ipv6 cef unresolved detailcommand:
- Figures related to adjacencies are moved to the show adjacency summarycommand (see the show adjacency summary).
- Nothing is displayed in the output if there are no unresolved adjacencies.
The table below compares the show ipv6 cef unresolved detailcommand output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 24 | show ipv6 cef unresolved detail Command Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show ipv6 cef unresolved detail
IPv6 CEF is enabled and running
Slow processing intvl = 1 seconds backoff level current/max 0/0
0 unresolved prefixes, 0 requiring adjacency update
IPv6 CEF default table
20 prefixes |
Router# show ipv6 cef unresolved detail
IPv6 CEF is enabled and running centrally.
VRF Default
6 prefixes (6/0 fwd/non-fwd)
Table id 0x1E000000
Database epoch: 0 (6 entries at this epoch)
2002::/128, epoch 0, flags rib only nolabel, rib defined all labels
recursive via 2003::BEEF, unresolved |
show ipv6 cef non-recursive
This feature provides the following change to the output of the show ipv6 cef non-recursivecommand:
The table below compares the show ipv6 cef non-recursivecommand output before ("Old" heading) and after ("New" heading) the Cisco Express Forwarding enhancements.
| Table 25 | show ipv6 cef non-recursive Command Output Before and After Cisco Express Forwarding Enhancements |
| Old |
New |
|---|---|
Router# show ipv6 cef non-recursive
2001:1:12::/64
nexthop FE80::2D0:1FF:FEE4:6800 FastEthernet0/1
2001:2:13::/64
nexthop FE80::2D0:1FF:FEE4:6800 FastEthernet0/1
2001:2:22::/64
nexthop FE80::2D0:1FF:FEE4:6800 FastEthernet0/1 |
Router# show ipv6 cef non-recursive
::/0
no route
::/127
discard
2003::/128
nexthop 3003::DEAD Ethernet2/0
FE80::/10
receive for Null0
FF00::/8
multicast |
New Commands for the CEF Feature
This section does not contain all new Cisco Express Forwarding commands. It contains only new commands introduced with the Cisco Express Forwarding enhancements to provide the same level of information that was available with the use of other commands before the Cisco Express Forwarding enhancements were implemented. Sample output is provided for the following new commands:
- show adjacency link
- show adjacency
- show adjacency detail
- show cef tree
- test cef table consistency detail
- show adjacency link
- show adjacency
- show adjacency detail
- show cef tree
- test cef table consistency detail
show adjacency link
The show adjacency link ipv4command and the show adjacency link ipv6command display information about IPv4 and IPv6 traffic, respectively, in the Cisco Express Forwarding adjacency table or the hardware Layer 3-switching adjacency table.
Per-protocol and interface summary adjacency information was moved from the show adjacency summary command to the show adjacency link command.
Following is sample output of the show adjacency link ipv4 command.
Router# show adjacency link ipv4
Protocol Interface Address
IP FastEthernet0/0 10.60.17.2(6)
IP FastEthernet0/0 10.60.17.20(6)
IP FastEthernet0/0 10.60.17.254(7)
IP FastEthernet0/1 172.17.22.1(16)
Following is sample output of the show adjacency link ipv6 command.
Router# show adjacency link ipv6
Protocol Interface Address
IPV6 FastEthernet0/1 2001:2:22::1(6)
IPV6 FastEthernet0/1 2001:2:22::2(3) (incomplete)
IPV6 FastEthernet0/1 FE80::2D0:1FF:FEE4:6800(14)
IPV6 Serial3/0 point2point(7)
IPV6 Serial3/1 point2point(10
show adjacency
The show adjacency prefix command shows adjacency information for the specified prefix.
Following are sample outputs from the show adjacency prefix command for an IPv4 prefix and an IPv6 prefix:
Router# show adjacency 172.17.22.1/24 Protocol Interface Address IP FastEthernet0/1 172.17.22.1(16) Router# show adjacency 2001:2:22::1/64 Protocol Interface Address IPV6 FastEthernet0/1 2001:2:22::1(6)
show adjacency detail
The show adjacency prefix detail command provides additional adjacency information for a specified prefix.
Information about the adjacency epoch was removed from the show ip cef epoch and show ipv6 cef epoch commands and is available from the show adjacency prefix detail command.
Following are sample outputs from the show adjacency prefix detail command for an IPv4 prefix and an IPv6 prefix:
Router# show adjacency 172.17.22.1/24 detail Protocol Interface Address IP FastEthernet0/1 172.17.22.1(16) 0 packets, 0 bytes epoch 0 sourced in sev-epoch 3 Encap length 14 00D001E4680000055FAF2C060800 ARP Router# show adjacency 2001:2:22::1/64 detail Protocol Interface Address IPV6 FastEthernet0/1 2001:2:22::1(6) 0 packets, 0 bytes epoch 0 sourced in sev-epoch 3 Encap length 14 00D001E4680000055FAF2C0686DD IPv6 ND
show cef tree
The show{ip| ipv6} cef treecommand displays summary information about the underlying data structures representing the specified FIB tree.
Mtrie data structure information was removed from several commands for the implementation of the Cisco Express Forwarding enhancements. This command provides the Mtrie information removed from the show ip cef summary, show ip cef internal, and show ip cef detail commands.
Following is sample output for the show ip cef tree command:
Router# show ip cef tree
VRF Default tree information:
MTRIE/RTREE storing IPv4 addresses
24 entries (24/0 fwd/non-fwd)
Forwarding tree:
Forwarding lookup routine: IPv4 mtrie 8-8-8-8 optimized
33 inserts, 9 deletes
8-8-8-8 stride pattern
short mask protection enabled for <= 4 bits without process suspension
24 leaves (672 bytes), 22 nodes (22880 bytes)
25208 total bytes
leaf ops: 33 inserts, 9 deletes
leaf ops with short mask protection: 2 inserts, 1 delete
per-prefix length stats: lookup off, insert off, delete off
refcounts: 1356 leaf, 1324 node
node pools:
pool[C/8 bits]: 22 allocated (0 failed), 22880 bytes
Non-Forwarding tree:
38 inserts, 38 deletes
0 leaves (0 bytes), 0 nodes (0 bytes)
0 total bytes
test cef table consistency detail
The test cef table consistency detail command displays recorded Cisco Express Forwarding consistency records found by the following detection mechanisms: lc-detect, scan-rib-ios, scan-ios-rib, scan-lc-rp, and scan-rp-lc. The scan-lc-rp and scan-rp-lc detection mechanisms are available only on routers with line cards. You can configure the Cisco Express Forwarding prefix consistency-detection mechanisms using the cef table consistency-check command.
This command provides output that replaces the output provided by the removed and obsolete show ip cef inconsistency records, show ip cef inconsistency now, and show ip cef inconsistency now detailcommands.
Following is sample output for the test cef table consistency detailcommand:
Router# test cef table consistency detail
full-scan-rib-ios: Checking IPv4 RIB to FIB consistency
full-scan-rib-ios: FIB checked 12 prefixes, and found 0 missing.
full-scan-ios-rib: Checking IPv4 FIB to RIB consistency
full-scan-ios-rib: Checked 12 FIB prefixes in 1 pass, and found 0 extra.
full-scan-rp-lc: Sent 26 IPv4 prefixes to linecards in 1 pass
full-scan-rp-lc: Initiated IPv4 FIB check on linecards..4..1..0..
full-scan-rp-lc: FIB IPv4 check completed on linecards..1..0..4..
full-scan-rp-lc: Linecard 4 checked 26 IPv4 prefixes (ignored 0). 0 inconsistent.
full-scan-rp-lc: Linecard 1 checked 26 IPv4 prefixes (ignored 0). 0 inconsistent.
full-scan-rp-lc: Linecard 0 checked 26 IPv4 prefixes (ignored 0). 0 inconsistent.
full-scan-rib-ios: Checking IPv6 RIB to FIB consistency
full-scan-rib-ios: FIB checked 16 prefixes, and found 5 missing.
full-scan-ios-rib: Checking IPv6 FIB to RIB consistency
full-scan-ios-rib: Checked 11 FIB prefixes in 1 pass, and found 0 extra.
full-scan-rp-lc: Sent 11 IPv6 prefixes to linecards in 1 pass
full-scan-rp-lc: Initiated IPv6 FIB check on linecards..4..1..0..
full-scan-rp-lc: FIB IPv6 check completed on linecards..1..4..0..
full-scan-rp-lc: Linecard 4 checked 11 IPv6 prefixes (ignored 0). 0 inconsistent.
full-scan-rp-lc: Linecard 1 checked 11 IPv6 prefixes (ignored 0). 0 inconsistent.
full-scan-rp-lc: Linecard 0 checked 11 IPv6 prefixes (ignored 0). 0 inconsistent.
No IPv4 inconsistencies found, check took 00:00:01.444
Warning: 5 IPv6 inconsistencies found, check took 00:00:01.240
Unchanged CEF show Commands
Some Cisco Express Forwarding show commands related to the Cisco Express Forwarding enhancements were not changed with the introduction of the enhancements. The output of the following commands was not changed:
- show cef idb
- show cef interface
- show ip cef
- show ip cef non-recursive
- show ipv6 cef
- show ipv6 cef adjacency
Additional References
Related Documents
| Related Topic |
Document Title |
|---|---|
| Cisco IOS commands |
|
| Description of Cisco Express Forwarding commands |
Cisco IOS IP Switching Command Reference |
| Description of Cisco Express Forwarding IPv6 commands |
Cisco IOS IPv6 Command Reference |
| Information on MFI enhancements |
MPLS Infrastructure Changes: Introduction of MFI and Removal of MPLS LSC and LC-ATM Features |
Technical Assistance
| Description |
Link |
|---|---|
| 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 CEF Enhancements
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 www.cisco.com/go/cfn. An account on Cisco.com is not required.
| Table 26 | Feature Information for Cisco Express Forwarding |
| Feature Name |
Releases |
Feature Information |
|---|---|---|
| Cisco Express Forwarding Enhancements: Introduction of CLI Changes and Removal of IPv4 Fast Switching |
12.4(20)T |
The purpose of this document is to describe the changes based on the Cisco Express Forwarding infrastructure scalability enhancements that have been implemented to adapt to the evolution of the Internet and to support new platforms and features. The changes are the removal of IP fast switching and the introduction of command line interface (CLI) modifications. This document lists Cisco Express Forwarding CLI commands that are removed, replaced, changed, and new. To help you transition to the new CLI format, the document illustrates the output for new commands and changed commands. Enhancements to Cisco Express Forwarding enable it to operate with the Multiprotocol Label Switching (MPLS) Forwarding Infrastructure (MFI) and guarantee consistency across Cisco IOS release trains. Cisco Express Forwarding infrastructure changes were introduced and implemented in the Cisco IOS 12.2(25)S-based releases and were added for T releases in Cisco IOS Release 12.4(20)T. 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. In Cisco IOS Release 12.4(20)T, this feature was introduced. |
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 (RP) to perform express forwarding. Distributed Cisco Express Forwarding is the other mode of Cisco Express Forwarding operation.
distributed Cisco Express Forwarding --A type of Cisco Express Forwarding switching 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. 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.
IDB --Interface Descriptor Block. An IDB is a special control structure internal to the Cisco IOS software that contains information such as the IP address, interface state, and packet statistics. Cisco IOS software maintains one IDB for each interface present on a platform and one IDB for each subinterface.
IPRM --IP Rewrite Manager. The IPRM is a module that manages the interaction between Cisco Express Forwarding, the IP Label Distributions Modules (LDM), and the Multiprotocol Label Switching (MPLS) Forwarding Infrastructure (MFI).
Mtrie --multiway tree. The Mtrie is a data structure in which routes are stored. The Mtrie is part of the IP lookup algorithm used in Cisco Express Forwarding.
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, 10.0.0.0/16 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.
RIB --Routing Information Base. A central repository of routes that contains Layer 3 reachability information and destination IP addresses or prefixes. The RIB is also known as the routing table.
RP --Route Processor. The processor module in the Cisco 7000 series routers that contains the CPU, system software, and most of the memory components that are used in the router. It is sometimes called a supervisory processor.
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 provider edge (PE) router.
Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL: www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1110R)
Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.
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