Users Guide

To view IGMP groups:
OS10# show ip igmp groups
Total Number of Groups: 100
IGMP Connected Group Membership
Group Address Interface Mode Uptime Expires Last Reporter
225.1.1.1 vlan121 IGMPv2-Compat 12:39:00 00:01:58 121.1.1.10
225.1.1.2 vlan121 IGMPv2-Compat 12:39:00 00:01:58 121.1.1.10
225.1.1.3 vlan121 IGMPv2-Compat 12:39:00 00:01:58 121.1.1.10
225.1.1.4 vlan121 IGMPv2-Compat 12:39:00 00:01:58 121.1.1.10
225.1.1.5 vlan121 IGMPv2-Compat 12:39:00 00:01:58 121.1.1.10
225.1.1.6 vlan121 IGMPv2-Compat 12:39:00 00:01:58 121.1.1.10
225.1.1.7 vlan121 IGMPv2-Compat 12:39:00 00:01:58 121.1.1.10
225.1.1.8 vlan121 IGMPv2-Compat 12:39:00 00:01:58 121.1.1.10
225.1.1.9 vlan121 IGMPv2-Compat 12:39:00 00:01:58 121.1.1.10
225.1.1.10 vlan121 IGMPv2-Compat 12:39:00 00:01:58 121.1.1.10
225.1.1.11 vlan121 IGMPv2-Compat 12:39:00 00:01:58 121.1.1.10
225.1.1.12 vlan121 IGMPv2-Compat 12:39:00 00:01:58 121.1.1.10
225.1.1.13 vlan121 IGMPv2-Compat 12:39:00 00:01:58 121.1.1.10
225.1.1.14 vlan121 IGMPv2-Compat 12:39:00 00:01:58 121.1.1.10
225.1.1.15 vlan121 IGMPv2-Compat 12:39:00 00:01:58 121.1.1.10
225.1.1.16 vlan121 IGMPv2-Compat 12:39:00 00:01:58 121.1.1.10
IGMP snooping
IGMP snooping uses the information in IGMP packets to generate a forwarding table that associates ports with multicast
groups. When switches receive multicast frames, they forward them to their intended receivers. OS10 supports IGMP snooping
on virtual local area network (VLAN) interfaces.
Effective with OS10 release 10.4.3.0, IGMP snooping is enabled by default.
NOTE:
OS10 supports IGMP snooping only with proxy reporting. OS10 does not relay the IGMP join packets received from
hosts as is. Instead, OS10 generates, bundles, and sends IGMP join packets to mrouter port based on the version of IGMP
queries received from IGMP routers. Proxy reporting reduces the number of IGMP control packets sent to the multicast
router.
Configuration notes
All Dell EMC PowerSwitches except MX-Series, S4200-Series, S5200 Series, and Z9332F-ON:
If you configure and unconfigure a static connection to a multicast router on an interface using the ip igmp snooping mrouter
interface command in VLAN mode, the router port still appears in the show ip igmp snooping mrouter vlan output. To remove
the VLAN port from the show output, configure the VLAN port again using the ip igmp snooping mrouter interface
command, and then unconfigure it using the no version of the command.
Configure IGMP snooping
● Enable IGMP snooping globally using the ip igmp snooping enable command in CONFIGURATION mode. This
command enables IGMP snooping on all VLAN interfaces.
NOTE:
You cannot enable IGMP or MLD snooping when configuring VLAN scale profile. If you enable VLAN scale profile,
OS10 disables IGMP and MLD snooping globally. When you disable VLAN scale profile configuration, you must explicitly
enable IGMP and MLD snooping globally.
● (Optional) Disable IGMP snooping on specific VLAN interfaces using the no ip igmp snooping command in VLAN
INTERFACE mode.
● (Optional) Multicast flood control is enabled by default. To disable the multicast flood restrict feature, use the no
multicast snooping flood-restrict command in CONFIGURATION mode. To reenable the feature globally, use
the multicast snooping flood-restrict command in CONFIGURATION mode.
● In a network, the snooping switch is connected to a multicast Router that sends IGMP queries. On a Layer 2 network that
does not have a multicast router, you can configure the snooping switch to act as querier. Use the ip igmp snooping
querier command in VLAN INTERFACE mode to send the queries.
● OS10 learns the multicast router interface dynamically based on the interface on which IGMP membership query is received.
To assign a multicast router interface statically, use the ip igmp snooping mrouter interface interface—type
command in VLAN INTERFACE mode.
NOTE:
Multicast 1025