Cisco IE-4000 Software Configuration Manual page 389

Configuring FlexLinks and the MAC Address-Table Move Update
Configuration Examples for the FlexLinks and MAC Address-Table Move Update
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# interface GigabitEthernet1/17
Switch(config-if)# switchport backup interface GigabitEthernet1/18 multicast fast-convergence
Switch(config-if)# exit
Switch# show interfaces switchport backup detail
Switch Backup Interface Pairs:
Active
------------------------------------------------------------------------
GigabitEthernet1/17
Preemption Mode : off
Multicast Fast Convergence : On
Mac Address Move Update Vlan : auto
This output shows a querier for VLAN 1 and 401 with their queries reaching the switch through the configured port:
Switch# show ip igmp snooping querier
Vlan IP Address
-------------------------------------------------------------
1 1.1.1.1
401 41.41.41.1
This is output for the show ip igmp snooping mrouter command for VLAN 1 and 401:
Switch# show ip igmp snooping mrouter
Vlan ports
---- -----
1 Gi1/17(dynamic), Gi1/18(dynamic)
401 Gi1/17(dynamic), Gi1/18(dynamic)
Similarly, both the FlexLinks ports are a part of the learned groups. In this example, the port is a receiver/host in VLAN
1, which is interested in two multicast groups:
Switch# show ip igmp snooping groups
Vlan Group
-----------------------------------------------------------------------
1 228.1.5.1
1 228.1.5.2
Whenever a host responds to the general query, the switch forwards this report on all the mrouter ports. When you turn
on this feature through the command-line port, and when a report is forwarded by the switch on the configured
GigabitEthernet1/17, it is also leaked to the backup port GigabitEthernet1/18. The upstream router learns the groups and
starts forwarding multicast data, which is dropped at the ingress because the GigabitEthernet1/18 is blocked. When the
active link, GigabitEthernet1/17 goes down, the backup port, GigabitEthernet1/18, begins forwarding. You do not need
to send any proxy reports because the multicast data is already being forwarded by the upstream router. By leaking
reports to the backup port, a redundant multicast path has been set up, and the time taken for the multicast traffic
convergence is minimal.
Configuring a Backup Interface: Example
This example shows how to configure an interface with a backup interface and to verify the configuration:
Switch# configure terminal
Switch(conf)# interface GigabitEthernet1/17
Switch(conf-if)# switchport backup interface GigabitEthernet1/18
Switch(conf-if)# end
Switch# show interfaces switchport backup
Switch Backup Interface Pairs:
Interface
GigabitEthernet1/18
IGMP Version Port
v2 Gi1/17
v2 Gi1/17
Type Version Port List
igmp v2 Gi1/17, Gi1/18, Gi1/17
igmp v2 Gi1/17, Gi1/18, Gi1/17
Backup Interface State
Active Up/Backup Standby
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