Brocade FastIron Ethernet Switch Traffic Management Guide - Manual (Page 69)

ACL based adaptive rate limiting parameters (Continued) TABLE 31
Parameter Definition
Committed Burst Size
(CBS) The number of bytes per second (packets per second in ICX 6650) 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). Brocade
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 maximum kilobit (packets per second in ICX 6650) 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 (packets per second in ICX 6650) allowed in a burst
before all packets will exceed the peak information rate. The PBS must be a value
greater than zero (0). Brocade recommends that this value be equal to or greater than
the size of the largest possible IP packet in the stream.
If a port receives more than the configured bit or byte (packets per second in ICX 6650) rate in a one-
second interval, the port will either drop or forward subsequent data in hardware, depending on the
action you specify.
Configuring ACL-based adaptive rate limiting
To implement the ACL-based adaptive rate limiting feature, first create a traffic policy, and then
reference the policy in an extended ACL statement. Lastly, bind the ACL to an interface. Complete the
following steps.
1. Create a traffic policy. Enter a command such as the following.
device(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. Enter a command such as the following.
device(config)#access-list 104 permit ip host 10.10.12.2 any traffic-policy
TPDAfour
3. Bind the ACL to an interface. Enter commands such as the following.
device(config)#interface ethernet 7
device(config-if-e7)#ip access-group 104 in
device(config-if-e7)#exit
The previous 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.
NOTE
On ICX 6650, rate-limiting is packet-based.
Syntax: [no] traffic-policy TPDname rate-limit adaptive cir cirvalue cbs cbsvalue pir pirvalue
pbs pbsvalue exceed-action action [ count ]
Syntax: access-list num { permit | deny.... } traffic policy TPDname
Syntax: [no] ip access-group num in
Configuring ACL-based adaptive rate limiting
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