Foundry Networks FESX User Manual

Traffic Policies
December 2005 © Foundry Networks, Inc. 15 5
<cir value> is the committed information rate in kbps. This value can be from 64 – 1000000 Kbps.
exceed-action <action> specifies the action to be taken when packets exceed the configured cir value. See
“Specifying the Action to be Taken for Packets that are Over the Limit” .
The count parameter is optional and enables ACL counting. See “ACL and Rate Limit Counting” on page 15-7.
Configuring ACL-Based Adaptive Rate Limiting
Use the procedures in this section to configure ACL-based adaptive rate limiting. Before configuring this feature,
see what to consider in “Configuration Notes and Feature Limitations” on page 15-2.
Table 1 lists the configurable parameters for ACL-based adaptive rate limiting:
If a port receives more than the configured bit or byte rate in a one-second interval, the port will either drop or
forward subsequent data in hardware, depending on the action you specify.
To implement the ACL-based adaptive rate limiting feature, first create a traffic policy then reference the policy in
an extended ACL statement. Lastly, bind the ACL to an interface. Follow the steps below.
1. Create a traffic policy. Enter a command such as the following:
FESX424 Switch(config)# traffic-policy TPDAfour rate-limit adaptive cir 10000
cbs 1600 pir 20000 pbs 4000 exceed-action drop
2. Create a new extended ACL entry or modify an existing extended ACL entry that references the traffic policy.
For example:
FESX424 Switch(config)# access-list 104 permit ip host 210.10.12.2 any traffic-
policy TPDAfour
3. Bind the ACL to an interface.
FESX424 Switch(config)# int e 7
FESX424 Switch(config-if-e7)# ip access-group 104 in
FESX424 Switch(config-if-e7)# exit
The above commands configure an adaptive rate limiting policy that enforces a guaranteed committed rate of
10000 kbps on port e7 and allows bursts of up to 1600 bytes. It also enforces a peak rate of 20000 kbps and
allows bursts of 4000 bytes above the PIR limit. If the port receives additional bits during a given one-second
interval, the port drops all packets on the port until the next one-second interval starts.
Table 1: ACL-Based Adaptive Rate Limiting Parameters
Parameter Definition
Committed Information Rate (CIR) The guaranteed kilobit rate of inbound traffic that is allowed on a port.
Committed Burst Size (CBS) The number of bytes per second allowed in a burst before some
packets will exceed the committed information rate. Larger bursts are
more likely to exceed the rate limit. The CBS must be a value greater
than zero (0). Foundry recommends that this value be equal to or
greater than the size of the largest possible IP packet in a stream.
Peak Information Rate (PIR) The peak maximum kilobit rate for inbound traffic on a port. The PIR
must be equal to or greater than the CIR.
Peak Burst Size (PBS) The number of bytes per second allowed in a burst before all packets
will exceed the peak information rate. The PBS must be a value
greater than zero (0). Foundry recommends that this value be equal
to or greater than the size of the largest possible IP packet in the
stream.

Foundry Networks FESX Specifications

General

Brand	Foundry Networks
Model	FESX
Category	Switch
Language	English