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Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter46 Configuring IP Multicast Routing
Configuring IP Multicast Routing
For SSM mapping configuration examples:
http://www.cisco.com/en/US/docs/ios/12_3t/12_3t2/feature/guide/gtssmma.html
Configuring DNS-Based SSM Mapping
To configure DNS-based SSM mapping, you need to create a DNS server zone or add records to an
existing zone. If the routers that are using DNS-based SSM mapping are also using DNS for other
purposes, you should use a normally configured DNS server. If DNS-based SSM mapping is the only
DNS implementation being used on the router, you can configure a false DNS setup with an empty root
zone or a root zone that points back to itself.
Beginning in privileged EXEC mode, follow these steps to configure DNS-based SSM mapping:
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 ip igmp ssm-map enable Enable SSM mapping for groups in a configured SSM range.
Step3 ip igmp ssm-map query dns (Optional) Enable DNS-based SSM mapping.
By default, the ip igmp ssm-map command enables DNS-based SSM
mapping. Only the no form of this command is saved to the running
configuration.
Note Use this command to re-enable DNS-based SSM mapping if
DNS-based SSM mapping is disabled.
Step4 ip domain multicast domain-prefix (Optional) Change the domain prefix used by the switch for DNS-based
SSM mapping.
By default, the switch uses the ip-addr.arpa domain prefix.
Step5 ip name-server server-address1
[server-address2... server-address6]
Specify the address of one or more name servers to use for name and
address resolution.
Step6 Repeat Step 5 to configure additional
DNS servers for redundancy, if required.
Step7 end Return to privileged EXEC mode.
Step8 show running-config Verify your entries.
Step9 copy running-config startup-config (Optional) Save your entries in the configuration file.