Manual
Table Of Contents
- 1. INTRODUTION
- 2. INSTALLATION
- 3. SWITCH MANAGEMENT
- 4. WEB CONFIGURATION
- 4.1 Main WEB PAGE
- 4.2 System
- 4.3 Simple Network Management Protocol
- 4.4 Port Management
- 4.5 Link Aggregation
- 4.6 VLAN
- 4.7 Rapid Spanning Tree Protocol
- 4.8 Quality of Service
- 4.9 Multicast
- 4.10 IEEE 802.1X Network Access Control
- 4.10.1 Understanding IEEE 802.1X Port-Based Authentication
- 4.10.2 802.1X System Configuration
- 4.10.3 802.1X and MAC-Based Authentication Port Configuration
- 4.10.4 802.1X Port Status
- 4.10.5 802.1X and MAC-Based Authentication Statistics
- 4.10.6 Windows Platform RADIUS Server Configuration
- 4.10.7 802.1X Client Configuration
- 4.11 Access Control Lists
- 4.12 Address Table
- 4.13 Port Security (To be Continued)
- 4.14 LLDP
- 4.15 Network Diagnastics
- 4.16 Stacking – SGSW-24040 / SGSW-24040R
- 4.17 Power over Ethernet (SGSW-24040P / SGSW-24040P4)
- 5. COMMAND LINE INTERFACE
- 6. Command Line Mode
- 6.1 System Command
- 6.2 Port Management Command
- 6.3 Link Aggregation Command
- 6.4 VLAN Configuration Command
- 6.5 Spanning Tree Protocol Command
- 6.6 Multicast Configuration Command
- 6.7 Quality of Service Command
- 6.8 802.1x Port Access Control Command
- 6.9 Access Control List Command
- 6.10 MAC Address Table Command
- 6.11 LLDP Command
- 6.12 Stack Management Command
- 6.13 Power over Ethernet Command
- 7. SWITCH OPERATION
- 8. POWER OVER ETHERNET OVERVIEW
- 9. TROUBLE SHOOTING
- APPENDEX A
- APPENDEX B : GLOSSARY

User’s Manual of WGSW-24040 Series
SGSW-24040/24240 Series
135
4.9 Multicast
4.9.1 IGMP Snooping
The Internet Group Management Protocol (IGMP) lets host and routers share information about multicast groups
memberships. IGMP snooping is a switch feature that monitors the exchange of IGMP messages and copies them to the CPU
for feature processing. The overall purpose of IGMP Snooping is to limit the forwarding of multicast frames to only ports that are
a member of the multicast group.
About the Internet Group Management Protocol (IGMP) Snooping
Computers and network devices that want to receive multicast transmissions need to inform nearby routers that they will
become members of a multicast group. The Internet Group Management Protocol (IGMP) is used to communicate this
information. IGMP is also used to periodically check the multicast group for members that are no longer active. In the case
where there is more than one multicast router on a sub network, one router is elected as the ‘queried’. This router then keeps
track of the membership of the multicast groups that have active members. The information received from IGMP is then used to
determine if multicast packets should be forwarded to a given sub network or not. The router can check, using IGMP, to see if
there is at least one member of a multicast group on a given subnet work. If there are no members on a sub network, packets
will not be forwarded to that sub network.
Figure 4-9-1 Multicast Service