Configuring inbound rate-limiting for broadcast and multicast traffic
You can configure rate-limiting (throttling) of inbound broadcast and multicast traffic on the switch, which helps prevent the switch from being disrupted by traffic storms if they occur on the rate-limited port. The rate-limiting is implemented as a percentage of the total available bandwidth on the port.
The
rate-limit command can be executed from the global or interface context, for Example:
switch(config)# interface 3 rate-limit bcast in percent 10
or
switch(config)# interface 3 switch(eth-3)# rate-limit bcast in percent 10
Syntax:
rate-limit {< bcast | mcast >} in percent < 0-100 >
Parameters
in percent <0-100>
no rate-limit {<bcast | [mcast >]} in
Enables rate-limiting and sets limits for the specified inbound broadcast or multicast traffic. Only the amount of traffic specified by the percent is forwarded.
Default: Disabled
If you want to set a limit of 50% on inbound broadcast traffic for port 3, you can first enter interface context for port 3 and then execute the
rate-limit command, as shown in
Inbound broadcast rate-limiting of 50% on port 3. Only 50% of the inbound broadcast traffic will be forwarded.
Inbound broadcast rate-limiting of 50% on port 3
switch(config)# int 3 switch(eth-3)# rate-limit bcast in percent 50 switch(eth-3)# show rate-limit bcast Broadcast-Traffic Rate Limit Maximum % Port | Inbound Limit Mode Radius Override ----- + ------------- --------- --------------- 1 | Disabled Disabled No-override 2 | Disabled Disabled No-override 3 | Disabled % No-override 4 | Disabled Disabled No-override 5 | Disabled Disabled No-override
If you rate-limit multicast traffic on the same port, the multicast limit is also in effect for that port, as shown in Inbound multicast rate-limiting of 20% on port 3. Only 20% of the multicast traffic will be forwarded.
Inbound multicast rate-limiting of 20% on port 3
switch(eth-3)# rate-limit mcast in percent 20 switch(eth-3)# show rate-limit mcast Multicast-Traffic Rate Limit Maximum % Port | Inbound Limit Mode Radius Override ----- + ------------- --------- --------------- 1 | Disabled Disabled No-override 2 | Disabled Disabled No-override 3 | 20 % No-override 4 | Disabled Disabled No-override
To disable rate-limiting for a port enter the
no form of the command, as shown in
Disabling inbound multicast rate-limiting for port 3.
Disabling inbound multicast rate-limiting for port 3
switch(eth-3)# no rate-limit mcast in switch(eth-3)# show rate-limit mcast Multicast-Traffic Rate Limit Maximum % Port | Inbound Limit Mode Radius Override ----- + ------------- --------- --------------- 1 | Disabled Disabled No-override 2 | Disabled Disabled No-override 3 | Disabled Disabled No-override 4 | Disabled Disabled No-override