Siemens S223 User Manual

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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.