Dell POWEREDGE M1000E User Manual
Page 533
21-5
Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
OL-13270-03
Chapter 21 Configuring Flex Links and the MAC Address-Table Move Update Feature
Understanding Flex Links and the MAC Address-Table Move Update
Similarly, both Flex Link ports are part of learned groups. Gigabit Ethernet2/0/11 is a receiver/host in
VLAN 1, which is interested in two multicast groups:
Switch# show ip igmp snooping groups
Vlan Group
Type Version Port
List
-----------------------------------------------------------------------
1
228.1.5.1 igmp
v2
Gi1/0/11, Gi1/0/12, Gi2/0/11
1
228.1.5.2 igmp
v2
Gi1/0/11, Gi1/0/12, Gi2/0/11
When a host responds to the general query, the switch forwards this report on all the mrouter ports. In
this example, when a host sends a report for the group 228.1.5.1, it is forwarded only on Gigabit
Ethernet1/0/11, because the backup port Gigabit Ethernet1/0/12 is blocked. When the active link,
Gigabit Ethernet1/0/11, goes down, the backup port, GigabitEthernet1/0/12, begins forwarding.
As soon as this port starts forwarding, the switch sends proxy reports for the groups 228.1.5.1 and
228.1.5.2 on behalf of the host. The upstream router learns the groups and starts forwarding multicast
data. This is the default behavior of Flex Link. This behavior changes when the user configures fast
convergence using the switchport backup interface gigabitethernet 1/0/12 multicast
fast-convergence command. This example shows enabling this feature:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# interface gigabitethernet 1/0/11
Switch(config-if)# switchport backup interface gigabitethernet 1/0/12 multicast
fast-convergence
Switch(config-if)# exit
Switch# show interfaces switchport backup detail
Switch Backup Interface Pairs:
Active
Interface
Backup Interface State
------------------------------------------------------------------------
GigabitEthernet1/0/11 GigabitEthernet1/0/12 Active Up/Backup Standby
Preemption Mode : off
Multicast Fast Convergence : On
Bandwidth : 100000 Kbit (Gi1/0/11), 100000 Kbit (Gi1/0/12)
Mac Address Move Update Vlan : auto
This output shows a querier for VLAN 1 and 401 with their queries reaching the switch through Gigabit
Ethernet 1/0/11:
Switch# show ip igmp snooping querier
Vlan
IP Address
IGMP Version
Port
-------------------------------------------------------------
1 1.1.1.1
v2
Gi1/0/11
401 41.41.41.1
v2
Gi1/0/11
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 Gi1/0/11(dynamic),
Gi1/0/12(dynamic)
401 Gi1/0/11(dynamic),
Gi1/0/12(dynamic)
Similarly, both the Flex Link ports are a part of the learned groups. Gigabit Ethernet 2/0/11 is a
receiver/host in VLAN 1, which is interested in two multicast groups:
Switch# show ip igmp snooping groups
Vlan Group
Type Version Port
List
-----------------------------------------------------------------------
1
228.1.5.1 igmp
v2
Gi1/0/11, Gi1/0/12, Gi2/0/11
1
228.1.5.2 igmp
v2
Gi1/0/11, Gi1/0/12, Gi2/0/11