API 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.
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:
With IGMP snooping configured, OS10 does not support scale profile VLAN configuration. To use scale profile
configuration with IGMP snooping, use the mode l3 command.
● (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:
IGMP snooping dynamically detects the mrouter interface based on IGMP queries that it receives. If there are more than
one multicast routers connected to the snooping switch, one of them will send IGMP queries and the interface
connected to that router is dynamically learnt as an mrouter port. You must configure the interfaces connected to other
multicast routers as static mrouter port.
● (Optional) Configure the IGMP version using the ip igmp version version-number command in VLAN INTERFACE
mode.
● (Optional) The fast leave option allows the IGMP snooping switch to remove an interface from the multicast group
immediately on receiving the leave message. Enable fast leave with the ip igmp snooping fast-leave command in
VLAN INTERFACE mode.
Multicast
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