Specifications

IP Switching Commands
clear cef table
ISW-13
Cisco IOS IP Switching Command Reference
May 2008
clear cef table
To clear the Cisco Express Forwarding tables, use the clear cef table command in privileged EXEC
mode.
clear cef table {ipv4 | ipv6} [vrf {vrf-name | *}]
Syntax Description
Command Default No default behaviors or values.
Command Modes Privileged EXEC
Command History
Usage Guidelines The clear cef table command clears the selected table or address family of tables (for IPv4 or IPv6) and
updates (refreshes) them throughout the router (including the Route Processor and line cards). The
command increments the table epoch, updates the tables, distributes the updated information to the line
cards, and performs a distributed purge of any stale entries in the tables based on the noncurrent epoch
number. This ensures that any inconsistencies that occurred over time are removed.
Because this command might require significant processing resources and can cause dropped traffic or
system error messages about excessive CPU use, it’s use is recommended only as a last resort for
debugging or mitigating serious problems.
Cisco Express Forwarding tables are also cleared automatically during bootup or online insertion and
removal (OIR) of line cards.
Note On the Cisco 10000 series routers, IPv6 is supported on Cisco IOS Release 12.2(28)SB or later
releases.
ipv4 Clears the Cisco Express Forwarding tables for IPv4 addresses.
ipv6 Clears the Cisco Express Forwarding tables for IPv6 addresses.
Note On the Cisco 10000 series routers IPv6 is supported on Cisco IOS
Release 12.2(28)SB and later releases.
vrf Specifies all VPN routing and forwarding (VRF) instance tables or a specific VRF table
for an IPv4 or IPv6 address.
vrf-name Clears the specific VRF table for IPv4 or IPv6 addresses.
* Clears all the VRF tables for IPv4 or IPv6 addresses.
Release Modification
12.2(25)S This command was introduced.
12.2(28)SB This command was integrated into Cisco IOS Release 12.2(28)SB.
12.2(33)SRA This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2(33)SXH This command was integrated into Cisco IOS Release 12.2(33)SXH.