Cisco Catalyst 3650 User Manual

The next-hop-based S-G-hash algorithm provides more flexible support for ECMP multicast load splitting
than S-hash algorithm and eliminates the polarization problem. Using the next-hop-based S-G-hash algorithm
for ECMP multicast load splitting enables multicast traffic from devices that send many streams to groups or
that broadcast many channels, such as IPTV servers or MPEG video servers, to be more effectively load split
across equal-cost paths.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
ip multicast multipath s-g-hash next-hop-based
4.
Repeat Steps 1 through 3 on all the routers in a redundant topology.
5.
end
6.
show ip rpf source-address [group-address]
7.
show ip route ip-address
DETAILED STEPS
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Router> enable
•
Enter your password if prompted.
Enters global configuration mode.configure terminal
Example:
Router# configure terminal
Step 2
Enables ECMP multicast load splitting based on source, group, and
next-hop-address using the next-hop-based S-G-hash algorithm.
ip multicast multipath s-g-hash
next-hop-based
Step 3
Example:
Router(config)# ip multicast
multipath s-g-hash next-hop-based
•
Because this command changes the way an RPF neighbor is selected,
it must be configured consistently on all routers in a redundant topology
to avoid looping.
Be sure to enable the ip multicast multipath command on the
router that is supposed to be the receiver for traffic from more than
one incoming interfaces, which is opposite to unicast routing. From
the perspective of unicast, multicast is active on the sending router
connecting to more than one outgoing interfaces.
Note
--Repeat Steps 1 through 3 on all the routers
in a redundant topology.
Step 4
Exits global configuration mode and returns to privileged EXEC mode.end
Step 5
IP Multicast Routing Configuration Guide, Cisco IOS XE Release 3SE (Catalyst 3650 Switches)
330 OL-29890-01
IP Multicast Optimization: IP Multicast Load Splitting across Equal-Cost Paths
Enabling ECMP Multicast Load Splitting

Cisco Catalyst 3650 Specifications

General

Brand	Cisco
Model	Catalyst 3650
Category	Switch
Language	English