Allied Telesis AR400 manual Snooper timer values

How clients leave groups: queries and timers > Snooper timer values

The command show ip igmp displays the timer for the most recently updated port as the group’s Refresh Time. From Software Version 291-08, the command show igmpsnooping vlan={<vid>all} detail displays the timers for each individual port.

Snooper timer values

As described in Step 5 above, when the Snooper receives a Specific Query from the Querier, it may update a timer for ports that forward that group. The following flow chart describes the decision-making process for updating the timer.

Start:

Switch receives Query for which it has a group entry.

Has the switch
previously seen a		no
Leave message?
	yes

For this

port, is the group

Do not alter port-specific

entry dynamic

(not static)?

yes

no

group membership timer. Flood Query out all ports.

Is the		port’s
current		timer ≥
LMQI fro		m Querier	no
￿ LMQC from
Snooper?
	yes

Set port-specific group membership timer to: LMQI from Querier

￿LMQC from Snooper.

Note that:

zThe command show igmpsnooping displays the timer for the most recently updated port as the group’s Timeout in ... value. From Software Version 291-08, the command show igmpsnooping vlan={<vid>all} detail displays the timers for each individual port.

Page 59 AlliedWare™ OS How To Note: IGMP