Port Traffic Controls

Rate-Limiting

Using Both ICMP Rate-Limiting and All-Traffic Rate-Limiting on the Same Interface

ICMP and all-traffic rate-limiting can be configured on the same interface. All-traffic rate-limiting applies to all inbound or outbound traffic (including ICMP traffic), while ICMP rate-limiting applies only to inbound ICMP traffic.

Note that if the all-traffic load on an interface meets or exceeds the currently configured all-traffic inbound rate-limit while the ICMP traffic rate-limit on the same interface has not been reached, then all excess traffic will be dropped, including any inbound ICMP traffic above the all-traffic limit (regard­ less of whether the ICMP rate-limit has been reached). Suppose, for example:

■The all-traffic inbound rate-limit on port “X” is configured at 55% of the port’s bandwidth.

■The ICMP traffic rate-limit on port “X” is configured at 2% of the port’s bandwidth.

If at a given moment:■Inbound ICMP traffic on port “X” is using 1% of the port’s bandwidth, and■Inbound traffic of all types on port “X” demands 61% of the ports’s bandwidth,

then all inbound traffic above 55% of the port’s bandwidth, including any additional ICMP traffic, will be dropped as long as all inbound traffic combined on the port demands 55% or more of the port’s bandwidth.

Displaying the Current ICMP Rate-Limit Configuration

The show rate-limit icmp command displays the per-interface ICMP rate-limit configuration in the running-config file.

Syntax: show rate-limit icmp [ port-list]

Without [ port-list], this command lists the ICMP rate-limit configuration for all ports on the switch. With [ port-list], this command lists the rate-limit configuration for the specified interface(s). This command operates the same way in any CLI context.

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