HP 7102dl - ProCurve Secure Router Configuration Manual page 632

Configuring Multicast Support for a Stub Network
Configuring IGMP Proxy for Multicast Stub Routing Support
Interval Function
query interval The query interval is how often
the interface broadcasts
queries to hosts on the
connected network.
query timeout Only one router on a subnet
acts as the designated
querier. However, other
interfaces still listen for IGMP
queries. The query timeout is
the time an interface waits for
a query before it assumes the
querier is down and begins
sending its own queries.
The query timeout should be at
least twice the query interval
so that a router can miss one
message without being timed
out.
query maximum The interface includes a
response time maximum response time in its
queries. Multicast hosts must
stagger their reports
somewhere within this limit.
last member query When an interface receives a
interval leave message from a
multicast host, it sends out a
query for that group to
determine whether it still has
any members on the network.
The last member query
interval specifies how often
the interface sends such
queries. Usually, this interval
is more rapid than that for
routine queries. After sending
two such queries, the
interface waits up to a second
longer for a response. If it does
not receive one, the router
removes the interface from
the multicast list entry for that
group's address.
12-20
Table 12-1. IGMP Intervals
Default
60 seconds
2 times the query
interval
10 seconds
1000 milliseconds
Range Command Syntax
0 to 65,535 seconds ip igmp query-interval
<seconds>
60 to 300 seconds ip igmp querier-
timeout <seconds>
0 to 25 seconds ip igmp query-max-
response-time
<seconds>
100 to 65,535 ip igmp last-member-
milliseconds query-interval
<milliseconds>