Specifications

IP Switching Commands
ip cef load-sharing algorithm
ISW-40
Cisco IOS IP Switching Command Reference
May 2008
Usage Guidelines The original CEF load-balancing algorithm produced distortions in load sharing across multiple routers
because of the use of the same algorithm on every router. When the load-balancing algorithm is set to
universal mode, each router on the network can make a different load sharing decision for each
source-destination address pair, and that resolves load-balancing distortions.
The tunnel algorithm is designed to share the load more fairly when only a few source-destination pairs
are involved.
The include-ports algorithm allows you to use the Layer 4 source and destination ports as part of the
load-balancing decision. This method benefits traffic streams running over equal-cost paths that are not
loadshared because the majority of the traffic is between peer addresses that use different port numbers,
such as Real-Time Protocol (RTP) streams. The include-ports algorithm is available in Cisco
IOS
Release
12.4(11)T and later releases.
Examples The following example shows how to enable the CEF load-balancing algorithm for tunnel environments:
configure terminal
!
ip cef load-sharing algorithm tunnel
exit
Related Commands Command Description
debug ip cef hash Records CEF load-balancing hash algorithm events
ip load-sharing Enables load balancing for CEF.