3Com CoreBuilder 3500, Implementation Manual, Page: 140 / 592

140 C
HAPTER
7: B
RIDGE
-W
IDE AND
B
RIDGE
P
ORT
P
ARAMETERS
Broadcast and
Multicast Limit for
Bridge Ports
You can assign a rate limit to any bridge port in the system to control the
per-second forwarding rate of incoming multicast and broadcast packets.
If the limit is reached, all remaining multicast and broadcast packets that
are received in that second of time are dropped. This feature is useful for
suppressing potential multicast or broadcast storms.
Important
Considerations
When you set a limit, consider the following:
■
A value of zero means that there is no limit set on the port. The system
default is zero on all ports.
■
You specify the limit in K frames per second (approximately 1000
frames per second). To determine an appropriate limit, measure the
normal amount of broadcast or multicast traffic on your network.
■
If you have IP multicast application traffic on your network, be sure
that any limits that you configure do not constrain these traffic flows.
■
If you want to specify a limit for a trunk, you only need to specify the
trunk’s anchor port (lowest-numbered port) when you configure the
limit for the entire trunk. However, be aware that the multicast limit
operates on
each link in the trunk.
■
There are similar options available through the Quality of Service
menu. For more information, see Chapter 17.