Description                                                    Configure ICMPv6 rate limiting for IPv6 to protect against denial-of-service (DoS) attacks.

Syntax                                                                  [no] icmpv6-rate-limit normal-rate lockup max-rate lockup-time




Maximum number of ICMPv6 packets allowed per second. If the ACOS device receives more than the normal rate of ICMPv6 packets, the excess packets are dropped until the next one-second interval begins. The normal rate can be 1-65535 packets per second.

lockup max-rate

Maximum number of ICMPv6 packets allowed per second before the ACOS device locks up ICMPv6 traffic. When ICMPv6 traffic is locked up, all ICMPv6 packets are dropped until the lockup expires. The maximum rate can be 1-65535 packets per second. The maximum rate must be larger than the normal rate.


Number of seconds for which the ACOS device drops all ICMPv6 traffic, after the maximum rate is exceeded. The lockup time can be 1-16383 seconds.

Default                                                                None

Mode                                                                   Configuration mode

Usage                                                                  This command configures ICMPv6 rate limiting globally for all traffic to or through the ACOS device. To configure ICMPv6 rate limiting on individual Ethernet interfaces, see the icmpv6-rate-limit command in the “Config Commands: Interface” chapter in the Network Config­uration Guide. To configure it in a virtual server template, see “slb template virtual-server” on page 259. If you configure ICMPv6 rate limiting filters at more than one of these levels, all fil­ters are applicable.

Specifying a maximum rate (lockup rate) and lockup time is optional. If you do not specify them, lockup does not occur.

Log messages are generated only if the lockup option is used and lockup occurs. Otherwise, the ICMPv6 rate-limiting counters are still incremented but log messages are not generated.

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