cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
692
Views
0
Helpful
2
Replies

IGMP Queierer "Global IP Address"?

RB6502
Beginner
Beginner

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??

1 Accepted Solution

Accepted Solutions

Harold Ritter
Cisco Employee
Cisco Employee

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,

Harold Ritter
Sr Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México

View solution in original post

2 Replies 2

Harold Ritter
Cisco Employee
Cisco Employee

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,

Harold Ritter
Sr Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México

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

.

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: