Specifications

IP Switching Commands
ip route-cache
ISW-53
Cisco IOS IP Switching Command Reference
May 2008
Usage Guidelines IP Route Cache
Note The Cisco 10000 series routers do not support the ip route-cache command.
Using the route cache is often called fast switching. The route cache allows outgoing packets to be
load-balanced on a per-destination basis rather than on a per-packet basis. The ip route-cache command
with no additional keywords enables fast switching.
Entering the ip route-cache command has no effect on a subinterface. Subinterfaces accept the no form
of the command; however, this disables Cisco Express Forwarding or distributed Cisco Express
Forwarding on the physical interface and all subinterfaces associated with the physical interface
IP Route Cache Same Interface
You can enable IP fast switching when the input and output interfaces are the same interface, using the
ip route-cache same-interface command. This configuration normally is not recommended, although
it is useful when you have partially meshed media, such as Frame Relay or you are running Web Cache
Communication Protocol (WCCP) redirection. You could use this feature on other interfaces, although
it is not recommended because it would interfere with redirection of packets to the optimal path.
IP Route Cache Flow
The flow caching option can be used in conjunction with Cisco Express Forwarding switching to enable
NetFlow, which allows statistics to be gathered with a finer granularity. The statistics include IP
subprotocols, well-known ports, total flows, average number of packets per flow, and average flow
lifetime.
Note The ip route-cache flow command has the same functionality as the ip flow ingress command, which
is the preferred command for enabling NetFlow. If either the ip route-cache flow command or the
ip flow ingress command is configured, both commands will appear in the output of the
show running-config command.
IP Route Cache Distributed
The distributed option is supported on Cisco routers with line cards and Versatile Interface Processors
(VIPs) that support Cisco Express Forwarding switching.
11.1CC cef keyword support was added for multiple platforms.
12.0 The policy keyword was added.
12.2(25)S This command was integrated into Cisco IOS Release 12.2(25)S. The ip
route-cache flow command is automatically remapped to the ip flow
ingress command.
12.2(28)SB This command was integrated into Cisco IOS Release 12.2(28)SB. This
command is not supported on the Cisco 10000 series router.
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.
Release Modification