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extreme switch sending multicast messages (igmpv2 membership query general) without any request from device


i am using extreme switch X460-24
I have vlan 174 configured with an ip pool which switch provides via dhcp
[config]
create vlan "vlan174"
configure vlan vlan174 tag 174
configure vlan vlan174 add ports 21-24 tagged
configure vlan vlan174 ipaddress 172.16.174.1 255.255.255.0
enable ipforwarding vlan vlan174
configure vlan vlan174 dhcp-address-range 172.16.174.2 - 172.16.174.200
configure vlan vlan174 dhcp-options default-gateway 172.16.174.1
configure vlan vlan174 dhcp-options dns-server 196.1.105.47
enable dhcp ports 21-24 vlan vlan174
[/config]

Why is switch sending multicast messages without being asked by any device ?
I can give wireshark log if required.
Thanks.

5 replies

Userlevel 5
If I am not mistaken, this is consistent with RFC2236, When a router is in the "No members present" state, it still sends out a general query to to find out what multicast groups would be of interests to any attached systems. If the general query timer expires and no response has been received from any host, it resets it and sends out the general query again. In EXOS the query internal is 125 seconds, and you can increase.
ok
how do I increase that interval ?
Userlevel 5
configure igmp [/code]The range is 1 to 214,748,364 seconds.
will try .
tell here , how it goes .
Userlevel 7
On EXOS, the command
code:

disable igmp [vlan NAME]


can be used to disable the IGMP querier function if it is not needed. Since IGMP snooping is enabled by default, an IGMP querier is needed for correct multicast data forwarding by default.

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