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Cisco ME 3800X and 3600X Switch Software Configuration Guide
OL-23400-01
Chapter 29 Configuring IP Unicast Routing
Configuring Protocol-Independent Features
Caution
Although the no ip route-cache cef interface configuration command to disable CEF on an interface is
visible in the CLI, we strongly recommend that you do not disable CEF on interfaces except for
debugging purposes.
Beginning in privileged EXEC mode, follow these steps to enable CEF globally and on an interface for
software-forwarded traffic if it has been disabled:
Configuring the Number of Equal-Cost Routing Paths
When a router has two or more routes to the same network with the same metrics, these routes can be
thought of as having an equal cost. The term parallel path is another way to see occurrences of equal-cost
routes in a routing table. If a router has two or more equal-cost paths to a network, it can use them
concurrently. Parallel paths provide redundancy in case of a circuit failure and also enable a router to
load balance packets over the available paths for more efficient use of available bandwidth.
Although the router automatically learns about and configures equal-cost routes, you can control the
maximum number of parallel paths supported by an IP routing protocol in its routing table.
Beginning in privileged EXEC mode, follow these steps to change the maximum number of parallel
paths installed in a routing table from the default:
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
ip cef
Enable CEF operation.
Step 3
interface interface-id
Enter interface configuration mode, and specify the Layer 3
interface to configure.
Step 4
ip route-cache cef
Enable CEF on the interface for software-forwarded traffic.
Step 5
end
Return to privileged EXEC mode.
Step 6
show ip cef
Display the CEF status on all interfaces.
Step 7
show cef linecard [detail]
Display CEF-related interface information.
Step 8
show cef interface [interface-id]
Display detailed CEF information for all interfaces or the
specified interface.
Step 9
show adjacency
Display CEF adjacency table information.
Step 10
copy running-config startup-config
(Optional) Save your entries in the configuration file.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
router {bgp | rip | ospf | eigrp}
Enter router configuration mode.
Step 3
maximum-paths maximum
Set the maximum number of parallel paths for the protocol routing
table. The range is from 1 to 8; the default is 4 for most IP routing
protocols, but only 1 for BGP.
Step 4
end
Return to privileged EXEC mode.
