Ipv6 Icmp Feature Configuration; Configuring Icmp Rate Limiting - Brocade Communications Systems FastIron SX 800 Configuration Manual

IPv6 ICMP feature configuration

Syntax: no ipv6 enable
To re-enable IPv6 after it has been disabled, enter ipv6 enable .
NOTE
IPv6 is disabled by default in the router code and must be configured on each interface that will support
IPv6.

IPv6 ICMP feature configuration

As with the Internet Control Message Protocol (ICMP) for IPv4, ICMP for IPv6 provides error and informational messages.
Implementation of the stateless auto configuration, neighbor discovery, and path MTU discovery features use ICMP messages.
This section explains how to configure following IPv6 ICMP features:
• ICMP rate limiting
• ICMP redirects

Configuring ICMP rate limiting

You can limit the rate at which IPv6 ICMP error messages are sent out on a network. IPv6 ICMP implements a token bucket algorithm.
To illustrate how this algorithm works, imagine a virtual bucket that contains a number of tokens. Each token represents the ability to send
one ICMP error message. Tokens are placed in the bucket at a specified interval until the maximum number of tokens allowed in the
bucket is reached. For each error message that ICMP sends, a token is removed from the bucket. If ICMP generates a series of error
messages, messages can be sent until the bucket is empty. If the bucket is empty of tokens, error messages cannot be sent until a new
token is placed in the bucket.
You can adjust the following elements related to the token bucket algorithm:
• The interval at which tokens are added to the bucket. The default is 100 milliseconds.
• The maximum number of tokens in the bucket. The default is 10 tokens.
For example, to adjust the interval to 1000 milliseconds and the number of tokens to 100 tokens, enter the following command.
device(config)# ipv6 icmp error-interval 1000 100
Syntax: ipv6 icmp error-interval interval [ number-of-tokens ]
The interval in milliseconds at which tokens are placed in the bucket can range from 0 - 2147483647. The maximum number of tokens
stored in the bucket can range from 1 - 200.
NOTE
If you retain the default interval value or explicitly set the value to 100 milliseconds, output from the show run command does
not include the setting of the ipv6 icmp error-interval command because the setting is the default.Also, if you configure the
interval value to a number that does not evenly divide into 100000 (100 milliseconds), the system rounds up the value to a
next higher value that does divide evenly into 100000. For example, if you specify an interval value of 150, the system rounds
up the value to 200.
ICMP rate limiting is enabled by default. To disable ICMP rate limiting, set the interval to zero.
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FastIron Ethernet Switch Layer 3 Routing
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