Brocade Communications Systems Brocate Ethernet Access Switch 6910 - Manual (Page 361)

Brocade 6910 Ethernet Access Switch Configuration Guide 311
53-1002581-01
Chapter
15
Rate Limit Commands
This function allows the network manager to control the maximum rate for traffic transmitted or
received on an interface. Rate limiting is configured on interfaces at the edge of a network to limit
traffic into or out of the network. Packets that exceed the acceptable amount of traffic are dropped.
Rate limiting can be applied to individual ports or trunks. When an interface is configured with this
feature, the traffic rate will be monitored by the hardware to verify conformity. Non-conforming
traffic is dropped.
rate-limit
This command defines the rate limit for a specific interface. Use this command without specifying a
rate to restore the default rate. Use the no form to restore the default status of disabled.
Syntax
rate-limit {input | output} [rate]
no rate-limit {input | output}
input – Input rate for specified interface
output – Output rate for specified interface
rate – Maximum value in Kbps.
(Range: 64-100000 Kbps for Fast Ethernet ports,
64-1000000 Kbps for Gigabit Ethernet ports)
Default Setting
Disabled
Command Mode
Interface Configuration (Ethernet, Port Channel)
Command Usage
Using both rate limiting and storm control on the same interface may lead to unexpected results.
For example, suppose broadcast storm control is set to 500 Kbps by the command “switchport
broadcast packet-rate 500,” and the rate limit is set to 20000 Kbps by the command “rate-limit
input 20000" on a Fast Ethernet port. Since 20000 Kbps is 1/5 of line speed (100 Mbps), the
received rate will actually be 100 Kbps, or 1/5 of the 500 Kbps limit set by the storm control
command. It is therefore not advisable to use both of these commands on the same interface.
TABLE 73 Rate Limit Commands
Command Function Mode
rate-limit Configures the maximum input or output rate for an interface IC