ZyXEL Communications MSAP2000 manual Igmp Snooping Screen

MSAP2000 AAMS User’s Guide

CHAPTER 9

IGMP Snooping

This chapter describes the IGMP Snooping screen.

9.1 IGMP Snooping

IGMP (Internet Group Multicast Protocol) is a session-layer protocol used to establish membership in a multicast group - it is not used to carry user data. Refer to RFC 1112 and RFC 2236 for information on IGMP versions 1 and 2 respectively.

A switch can passively snoop on IGMP Query, Report and Leave (IGMP version 2) packets transferred between IP multicast routers/switches and IP multicast hosts to learn the IP multicast group membership. It checks IGMP packets passing through it, picks out the group registration information, and configures multicasting accordingly. IGMP snooping allows the switch to learn multicast groups without you having to manually configure them.

The switch forwards multicast traffic destined for multicast groups (that it has learned from IGMP snooping or that you have manually configured) to ports that are members of that group. The switch discards multicast traffic destined for multicast groups that it does not know. IGMP snooping generates no additional network traffic, allowing you to significantly reduce multicast traffic passing through your switch.

9.2 IGMP Snooping Screen

Click Advanced Application and then IGMP Snooping in the navigation panel to display the IGMP Snooping screen as shown next. Use this screen to turn IGMP snooping off or on and view information collected by IGMP snooping.

Figure 42 IGMP Snooping

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