Specifications

IP Switching Commands
show cef drop
ISW-117
Cisco IOS IP Switching Command Reference
May 2008
show cef drop
To display a list of which packets each line card dropped, use the show cef drop command in user EXEC
or privileged EXEC mode.
show cef drop
Syntax Description This command has no arguments or keywords.
Command Modes User EXEC
Privileged EXEC
Command History
Usage Guidelines A line card might drop packets because of encapsulation failure, absence of route information, or
absence of adjacency information.
A packet is sent to a different switching path (punted) because CEF does not support the encapsulation
or feature, the packet is destined for the router, or the packet has IP options, such as time stamp and
record route. IP options are process switched.
Note If CEFv6 or dCEFv6 is enabled globally on the router, the show cef drop command displays IPv6 CEF
counter information and IPv4 CEF counter information. If CEFv6 or dCEFv6 is not enabled globally on
the router, the command displays only IPv4 CEF counter information.
Release Modification
11.2 GS This command was introduced to support the Cisco 12012 Internet router.
11.1 CC Multiple platform support was added.
12.0(22)S The display output for this command was modified to include support for
Cisco Express Forwarding for IPv6 (CEFv6) and distributed CEF for IPv6
(dCEFv6) packets.
12.0(23)S This command was integrated into Cisco IOS Release 12.0(23)S.
12.2(13)T This command was integrated into Cisco IOS Release 12.2(13)T. Previously
there was a show cef command, and drop was a keyword of that command.
12.2(14)S This command was integrated into Cisco IOS Release 12.2(14)S.
12.2(33)SRA This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX This command is supported in the Cisco IOS Release 12.2SX train. Support
in a specific 12.2SX release of this train depends on your feature set,
platform, and platform hardware.