User's Manual
Table Of Contents
- 1. INTRODUCTION
- 2. INSTALLATION
- 3. SWITCH MANAGEMENT
- 4. WEB CONFIGURATION
- 4.1 Main Web Page
- 4.2 System
- 4.3 Port Management
- 4.4 Link Aggregation
- 4.5 VLAN
- 4.5.1 VLAN Overview
- 4.5.2 IEEE 802.1Q VLAN
- 4.5.3 Management VLAN
- 4.5.4 Create VLAN
- 4.5.5 Interface Settings
- 4.5.6 Port to VLAN
- 4.5.7 Port VLAN Membership
- 4.5.8 Protocol VLAN Group Setting
- 4.5.9 Protocol VLAN Port Setting
- 4.5.10 GVRP Setting
- 4.5.11 GVRP Port Setting
- 4.5.12 GVRP VLAN
- 4.5.13 GVRP Statistics
- 4.5.14 VLAN setting example:
- 4.6 Spanning Tree Protocol
- 4.7 Multicast
- 4.8 Quality of Service
- 4.9 Security
- 4.10 ACL
- 4.11 MAC Address Table
- 4.12 LLDP
- 4.13 Diagnostics
- 4.14 Power over Ethernet (GS-4210-24P2S only)
- 4.15 RMON
- 4.16 Maintenance
- 5. COMMAND LINE INTERFACE
- 6. Command Line Mode
- 6.1 User Mode Commands
- 6.2 Privileged Mode Commands
- 6.2.1 clear command
- 6.2.2 clock command
- 6.2.3 configure command
- 6.2.4 copy command
- 6.2.5 debug command
- 6.2.6 delete command
- 6.2.7 disable command
- 6.2.8 end command
- 6.2.9 exit command
- 6.2.10 no command
- 6.2.11 ping command
- 6.2.12 reboot command
- 6.2.13 renew command
- 6.2.14 restore-defaults command
- 6.2.15 save command
- 6.2.16 show command
- 6.2.17 ssl command
- 6.2.18 traceroute command
- 6.2.19 udld command
- 6.3 Global Config Mode Commands
- 6.3.1 aaa Command
- 6.3.2 boot Command
- 6.3.3 bridge Command
- 6.3.4 class-map Command
- 6.3.5 clock Command
- 6.3.6 dos Command
- 6.3.7 dot1x Command
- 6.3.8 do Command
- 6.3.9 enable Command
- 6.3.10 end Command
- 6.3.11 errdisable Command
- 6.3.12 exit Command
- 6.3.13 gvrp Command
- 6.3.14 hostname Command
- 6.3.15 interface Command
- 6.3.16 ip Command
- 6.3.17 ipv6 Command
- 6.3.18 jumbo-frame Command
- 6.3.19 l2 Command
- 6.3.20 lacp Command
- 6.3.21 lag Command
- 6.3.22 line Command
- 6.3.23 lldp Command
- 6.3.24 logging Command
- 6.3.25 mac Command
- 6.3.26 management-vlan Command
- 6.3.27 mirror Command
- 6.3.28 no Command
- 6.3.29 policy-map Command
- 6.3.30 port-security Command
- 6.3.31 qos Command
- 6.3.32 radius Command
- 6.3.33 rate-limit Command
- 6.3.34 rmon Command
- 6.3.35 Snmp Command
- 6.3.36 sntp Command
- 6.3.37 spanning-tree Command
- 6.3.38 storm-control Command
- 6.3.39 system Command
- 6.3.40 tacacs Command
- 6.3.41 udld Command
- 6.3.42 username Command
- 6.3.43 vlan Command
- 6.3.44 voice-vlan Command
- 7. SWITCH OPERATION
- 8. POWER OVER ETHERNET OVERVIEW
- 9. TROUBLESHOOTING
- APPENDIX A
- EC Declaration of Conformity
User’s Manual of GS-4210-16T2S_24T2S_24P2S
IGMP Versions 1 and 2
Multicast groups allow members to join or leave at any time. IGMP provides the method for members and multicast routers to
communicate when joining or leaving a multicast group.
IGMP version 1 is defined in RFC 1112. It has a fixed packet size and no optional data.
The format of an IGMP packet is shown below:
IGMP Message Format
Octets
0 8 16 31
Checksum
T
ype Response Time
Group Address (all zeros if this is a query)
The IGMP Type codes are shown below:
Type Meaning
Members
hip Query (if Group Address is 0.0.0.0)
0x11
S
pecific Group Membership Query (if Group Address is
Present)
0x11
0x16 Membership Report (version 2)
0x17 Leave a Group (version 2)
0x12 Membership Report (version 1)
IGMP packets enable multicast routers to keep track of the membership of multicast groups, on their respective sub networks.
The following outlines what is communicated between a multicast router and a multicast group member using IGMP.
A host sends an IGMP “report” to join a group
A host will never send a report when it wants to leave a group (for version 1).
A host will send a “leave” report when it wants to leave a group (for version 2).
Multicast routers send IGMP queries (to the all-hosts group address: 224.0.0.1) periodically to see whether any group members
exist on their sub networks. If there is no response from a particular group, the router assumes that there are no group members
on the network.
The Time-to-Live (TTL) field of query messages is set to 1 so that the queries will not be forwarded to other sub networks.
IGMP version 2 introduces some enhancements such as a method to elect a multicast queried for each LAN, an explicit leave
message, and query messages that are specific to a given group.
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