Configuration Guide User guide

1518 FastIron Configuration Guide
53-1002494-02
Global IP multicast parameters
• Maximum number of DVMRP groups – You can change the maximum number of groups for
which the software will allocate memory. By default, FastIron X Series Layer 3 Switches support
up to 1024 DVMRP groups.
• Internet Group Membership Protocol (IGMP) V1 and V2 parameters – You can change the
query interval, group membership time, and maximum response time.
• Hardware forwarding of fragmented IP multicast packets – You can enable the Layer 3 switch
to forward all fragments of fragmented IP multicast packets in hardware.
Changing dynamic memory allocation for IP
multicast groups
Layer 3 switches support up to 1024 PIM groups and 1024 DVMRP groups by default. Memory for
the groups is allocated dynamically as needed. For each protocol, previous releases support a
maximum of 255 groups and 255 IGMP memberships.
NOTE
The number of interface groups you can configure for DVMRP and PIM is unlimited; therefore, the
system-max dvmrp-max-int-group and the system-max pim-max-int-group commands that define
their maximum table sizes have been removed.
The software allocates memory globally for each group, and also allocates memory separately for
each interface IGMP membership in a multicast group. An interface becomes a member of a
multicast group when the interface receives an IGMP group membership report. For example, if the
Layer 3 switch learns about one multicast group, global memory for one group is used. In addition,
if three interfaces on the device receive IGMP group membership reports for the group, interface
memory for three IGMP memberships also is used.
Since the same group can use multiple allocations of memory (one for the group itself and one for
each interface membership in the group), you can increase the maximum number of IGMP
memberships, up to 8192.
NOTE
The total for IGMP memberships applies to the device, not to individual interfaces. You can have up
to 8192 IGMP memberships on all the individual interfaces, not up to 8192 IGMP memberships on
each interface.
Defining the maximum number of DVMRP cache entries
The DVMRP cache system parameter defines the maximum number of repeated DVMRP traffic
being sent from the same source address and being received by the same destination address. To
define this maximum, enter the system-max dvmrp-mcache <num> command.
Brocade(config)#system-max dvmrp-mcache 500
Syntax: system-max dvmrp-mcache <num>
The <num> parameter specifies the maximum number of multicast cache entries for DVMRP. Enter
a number from 128 – 4096. The default is 512.