IGMP Queierer "Global IP Address"?

[RB6502]

I found many references to a router's

 Global IP Address 

in this document on multicast config, for instance:

Prerequisites for IGMP Snooping

Observe these guidelines when configuring the IGMP snooping querier:

• Configure the VLAN in global configuration mode.

• Configure an IP address on the VLAN interface. When enabled, the IGMP snooping querier uses the IP address as the query source address.

• If there is no IP address configured on the VLAN interface, the IGMP snooping querier tries to use the configured global IP address for the IGMP querier. If there is no global IP address specified, the IGMP querier tries to use the VLAN device virtual interface (SVI) IP address (if one exists). If there is no SVI IP address, the device uses the first available IP address configured on the device. The first IP address available appears in the output of the

  show ip interface privileged EXEC command 

  . The IGMP snooping querier does not generate an IGMP general query if it cannot find an available IP address on the device.

What is this referring to??

[Harold Ritter · Accepted solution]

Hi @RB6502 ,

> the configured global IP address for the IGMP querier. What is this referring to??

It refers to the global IGMP querier IP address configured using the following command;

ip igmp snooping querier <IP address>

It is useful to configure a global querier IP address if you have several vlans configured on the switch and you do not wish to configured a separate SVI and IP address for each one of them.

Regards,

[RB6502]

Thanks, Harold.  Very helpful!  The

 global IP address

is mentioned very early in that document, before that command is ever discussed.  Even when it is, I don't think it marries up the command with the term

router's global IP addres

.