Siemens S223 - Manual (Page 298)

UMN:CLI User Manual
SURPASS hiD 6615 S223/S323 R1.5
298 A50010-Y3-C150-2-7619
To display a configuration, use the following command.
Command Mode Description
show ip igmp snooping explicit-
tracking {vlan VLANS | port
PORTS | group A.B.C.D}
Enable
Global
Bridge Shows a configuration.
9.2.6.3 Immediate Block
For a Layer 2 IGMP v2 host interface to join an IP multicast group, a host sends an IGMP
membership report for the IP multicast group. For a host to leave a multicast group, it can
either ignore the periodic IGMP general queries or it can send an IGMP leave message.
When the switch receives an IGMP leave message from a host, it sends out an IGMP
group-specific query to determine whether any devices connected to that interface are in-
terested in traffic for the specific multicast group. The switch then updates the table entry
for that Layer 2 multicast group so that only those hosts interested in receiving multicast
traffic for the group are listed.
However, IGMP v3 hosts send IGMP v3 membership reports (with the allow group record
mode) to join a specific multicast group. When IGMP v3 hosts send membership reports
(with the block group record) to reject traffic from all sources in the previous source list,
the last host on the port will be removed by immediate-leave.
To configure the Immediate Block, use the following command.
Command Mode Description
ip igmp snooping immediate-
block
Enables immediate block on the system.
ip igmp snooping vlan VLANS
immediate-block
Global
Enables immediate block on a VLAN interface.
9.2.7 Multicast VLAN Registration (MVR)
Multicast VLAN Registration (MVR) is for applications using wide-scale deployment of
multicast traffic across an Ethernet ring-based service provider network. MVR allows a
subscriber on a port to subscribe or not to a multicast stream on the network-wide multi-
cast VLAN. It allows the single multicast VLAN to be shared in the network with subscrib-
ers remaining in separate VLANs. MVR helps to continuously send multicast streams in
the multicast VLAN, but to isolate the streams from the subscriber VLANs for bandwidth
and security reasons.
MVR assumes that subscribers subscribe or not (join and leave) these multicast streams
by sending out IGMP join and leave messages. These messages can originate from an
IGMP version-2-compatible host. Although MVR operates on the underlying mechanism
of IGMP snooping, the two features operate independently of each other. One can be en-
abled or disabled without affecting the behavior of the other feature. However, if IGMP
snooping and MVR are both enabled, MVR reacts only to join and leave messages from
multicast groups configured under MVR. Join and leave messages from all other multi-
cast groups are managed by IGMP snooping.