Configuring Rate Limiting for BUM Traffic

If high rates of traffic are being received by the device on a given port of that VLAN, you can limit the number of BUM packets or kilobytes received each second on that port.
  1. Enter global configuration mode. 
    device# configure terminal
  2. Enter interface configuration mode. 
    device(config)# interface ethernet 1/1/1
  3. Enable BUM rate limits.
    The rate limit can be set in kilobits per second (kbps) or packets per second (pps). You must specify "kbps" to set the rate limit in kilobits per second. If the unit of measure is not mentioned explicitly, the rate limit is measured in packets per second (pps).
  4. Set a broadcast rate limit by port speed in kbps. 
    device(config-if-e40000-1/1/1)# broadcast limit 100 kbps
    To set the broadcast rate limit by packets per second, enter the following command.
    device(config-if-e40000-1/1/1)# broadcast limit 100
  5. Set a multicast rate limit by port speed in kbps. 
    device(config-if-e40000-1/1/1)# multicast limit 400 kbps
    To set the multicast rate limit by packets per second, enter the following command.
    device(config-if-e40000-1/1/1)# multicast limit 400
  6. Set an unknown unicast rate limit by port speed in kbps. 
    device(config-if-e40000-1/1/1)# unknown-unicast limit 100 kbps
    To set the unknown unicast rate limit by packets per second, enter the following command.
    device(config-if-e40000-1/1/1)# unknown-unicast limit 100
  7. Verify the configuration. 
    device# show running-config interface ethernet 1/1/1 | include limit
broadcast limit 100 
multicast limit 400
unknown-unicast limit 100
    device# show running-config interface ethernet 1/1/1 | include limit
broadcast limit 100 kbps
multicast limit 400 kbps
unknown-unicast limit 100 kbps

Rate Limiting BUM Traffic Configuration Example

device# configure terminal
device(config)# interface ethernet 1/1/1
device(config-if-e40000-1/1/1)# broadcast limit 100 kbps
device(config-if-e40000-1/1/1)# unknown-unicast limit 100 kbps
device(config-if-e40000-1/1/1)# multicast limit 400 kbps

device(config-if-e40000-1/1/1)# show running-config interface | include  1/1/1 
interface ethernet 1/1/1
broadcast limit 100 kbps
unknown-unicast limit 100 kbps
multicast limit 400 kbps


device# configure terminal
device(config)# interface ethernet 1/1/2
device(config-if-e40000-1/1/2)# broadcast limit 100 
device(config-if-e40000-1/1/2)# unknown-unicast limit 100 
device(config-if-e40000-1/1/2)# multicast limit 400 

device(config-if-e40000-1/1/2)# show running-config interface | include  1/1/2
interface ethernet 1/1/2
broadcast limit 100 
unknown-unicast limit 100 
multicast limit 400
Parent topic: Configuring Rate Limiting