Configuration Guide User guide

FastIron Configuration Guide 1599
53-1002494-02
IGMP V3
If the interface, to which the client belongs, has IGMP V3 clients only. Therefore, all physical
ports on a virtual routing interface must have IGMP V3 enabled and no IGMP V1 or V2 clients
can be on the interface. (Although IGMP V3 can handle V1 and V2 clients, these two clients
cannot be on the interface in order for fast leave to take effect.)
No other client on the interface is receiving traffic from the group to which the client belongs.
Every group on the physical interface of a virtual routing interface keeps its own tracking
record. However, it can track group membership only; it cannot track by (source, group).
For example, two clients (Client A and Client B) belong to group1 but each is receiving traffic
streams from different sources. Client A receives a stream from (source_1, group1) and Client B
receives it from (source_2, group1). The router still waits for three seconds before it stops the
traffic because the two clients are in the same group. If the clients are in different groups, then the
three second waiting period is not applied and traffic is stopped immediately. The show ip igmp
group tracking command displays that clients in a group that are being tracked.
If a client sends a leave message, the client is immediately removed from the group. If a client does
not send a report during the the specified group membership time (the default is 140 seconds),
that client is removed from the tracking list.
To enable the tracking and fast leave feature, enter commands such as the following.
Brocade(config)#interface ve 13
Brocade(config-vif-13)#ip igmp tracking
Syntax: ip igmp tracking
Setting the query interval
The IGMP query interval period defines how often a router will query an interface for group
membership.
To modify the default value for the IGMP query interval, enter the ip igmp query-interval <num>
command.
Brocade(config)#ip igmp query-interval 120
Syntax: ip igmp query-interval <num>
The <num> variable specifies the IGMP query interval in number of seconds. Enter a value from 10
through 3600. The default value is 125.
Setting the group membership time
The group membership time defines how long a group will remain active on an interface in the
absence of a group report.
To define an IGMP membership time of 240 seconds, enter the ip igmp group-membership-time
<num> command.
Brocade(config)#ip igmp group-membership-time 240
Syntax: ip igmp group-membership-time <num>
The <num> variable specifies the IGMP group membership time in number of seconds. Enter a
value from 20 through 7200 seconds. The value you enter must be a little more than two times the
query interval (2*query-interval +10). The default value is 260.