Brocade Multi-Service IronWare QoS and Traffic Management Configuration Guide (Supporting R05.6.00) - Manual (Page 52)

38 Multi-Service IronWare QoS and Traffic Management Configuration Guide
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Rate limiting ARP packets
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To bind an ACL that rate limits broadcast traffic and forwards all other traffic without rate limiting,
enter commands such the following
Brocade(config)#int eth 14/1
Brocade(config-if-e10000-14/1)#rate-limit in access-gr 411 8144 100
Rate limiting ARP packets
You can limit the rate of ARP traffic that requires CPU processing on Brocade devices, such as ARP
request traffic, and ARP response addressed to the device. The feature is set globally and applies
to all ARP traffic received at the device. With this feature you can apply a defined policy map to all
ARP traffic bound for the CPU.
When the vlan-cpu-protection command is configured, ARP request packets are switched within a
VLAN by the hardware and thus cannot be rate-limited by the ip rate limit arp policy-map command.
To limit the rate of ARP packets that are forwarded by hardware, use interface-level, layer-2 inbound
ACLs with the “etype arp” option.
Configuring rate limiting of ARP packets
To rate limit ARP packets bound for the CPU using a policy map named “limitarp”, enter the
following command.
Brocade(config)# ip rate-limit arp policy-map limitarp
Syntax: [no] ip rate-limit arp policy-map map-name
The map-name variable is the name of the policy map to be used to provide parameters for rate
limiting CPU-bound ARP packets. If the policy map specified has not been defined, the rate limit
values are initialized to the line rate values.
Displaying statistics for ARP rate limiting
You can display ARP Rate Limiting Statistics using the following command.
Syntax: show rate-limit arp
This display shows the following information.
TABLE 13 Rate limit ARP display parameters
Parameter Description
Fwd The ARP traffic in bytes that has been sent to the CPU as a result of the
ARP rate limit policy since the device was started up or the counter was
reset.
Drop The ARP traffic in bytes that has been dropped as a result of the ARP
rate limit policy since the device was started up or the counter was reset.
Brocade# show rate-limit arp
Fwd: 1865392 Drop: 867731400 bytes
Re-mark: 1864800 Total: 871461592 bytes