User manual

Setting Flood Limits
Page 17-21
Setting Flood Limits
The flood limit is the number of bytes per second of flooded data that may be transmitted on
a port on a group. This limit is a mechanism for controlling broadcast storms on the network.
The default flood limit for a port, regardless of the media type, is 192,000 bytes per second.
You can change this default by configuring the flood limit on a per port or a per Group basis.
The
modvp command (described in Chapter 19, “Managing Groups and Ports”) allows you to
set the flood limit on a per port basis. The flc command (described in the following section)
allows you to set the flood limit on a per Group basis. Configuring the flood limit for a Group
is particularly useful when you need to disable flood limits for all ports in a single Group.
Setting Flood Limits for a Group
The flc command allows you to set flood limits for a Group. To set the flood limit for a Group
1. Enter the following at the system prompt follow these steps:
flc <groupNumber>
where <groupNumber> is the number of the group for which you are setting the flood
limit. For example, to set the flood limit on Group 2 you would specify:
flc 2
As a variation of this command, you can enter the dbrmap command without specifying a
group. This will display mapping information for all groups on this switch.
The following prompt displays:
Enter flood limit override value (bytes/second) for Group 2 (192000):
2. Enter the flood limit for this Group and press <Return>.
♦ Note ♦
A value of negative one (
-1) disables flood limits for the
Group.
When new ports are added to a group, they will use the flood limit specified through
flc. If a
value has not been specified through flc for this Group, then the default port value (192000)
is used.
♦ Note ♦
Flood limits set through
modvp (set on a per-port basis)
override the flood limit set through
flc.