ECS3510-26P_Management Guide R02

C HAPTER 26 | Interface Commands
Interface Configuration
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Multicast Storm Control: Disabled
Unknown Unicast Storm Control: Disabled
COMMAND MODE
Interface Configuration (Ethernet)
COMMAND USAGE
◆ When traffic exceeds the threshold specified for broadcast and
multicast or unknown unicast traffic, packets exceeding the threshold
are dropped until the rate falls back down beneath the threshold.
◆ Traffic storms can be controlled at the hardware level using this
command or at the software level using the auto-traffic-control
command. However, only one of these control types can be applied to a
port. Enabling hardware-level storm control on a port will disable
automatic storm control on that port.
◆ The rate limits set by this command are also used by automatic storm
control when the control response is set to rate limiting by the auto-
traffic-control action command.
◆ 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 Gigabit 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.
◆ The description of effective rate limiting (see Command Usage under
"Rate Limiting" on page 227) also applies to storm control.
N OTE : Due to a chip limitation, the switch supports only one limit for both
ingress rate limiting and storm control (including broadcast unknown
unicast, multicast, and broadcast storms).
EXAMPLE
The following shows how to configure broadcast storm control at 600
kilobits per second:
Console(config)#interface ethernet 1/5
Console(config-if)#switchport broadcast packet-rate 600
Console(config-if)#