Brocade Multi-Service IronWare Routing Configuration Guide (Supporting R05.6.00) - Manual (Page 467)

Multi-Service IronWare Routing Configuration Guide 439
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Configuring IPv6 ICMP
Configured Static Mroutes: 66
RIP: enabled
OSPF (default VRF): enabled
BGP: enabled, 1 active neighbor(s) configured
Syntax: show ipv6
You can display the entries in the IPv6 forwarding cache by entering the show ipv6 cache
command.
Syntax: show ipv6 cache [index-number | ipv6-prefix/prefix-length | ipv6-address | ethernet port
| ve number | tunnel number]
Configuring IPv6 ICMP
ICMP for IPv6 provides error and informational messages. The stateless auto-configuration,
neighbor discovery, and path MTU discovery features use ICMP messages.
This section explains how to configure the following IPv6 ICMP options:
• ICMP rate limiting
• ICMP redirects
• ICMP unreachable address or route messages
• ICMP error messages for source-routed IPv6 packets
• ICMP error messages for an unreachable address
• ICMP messages for an unreachable route
• ICMP error messages for IPv6 packets with hop-limit 0
• ICMP error messages for CES/CER devices
Configuring ICMP rate limiting
You can limit the rate at which IPv6 ICMP error messages are sent out on a network. For this
rate-limiting implementation, IPv6 ICMP uses a token bucket algorithm.
The algorithm works using a virtual bucket that contains a number of tokens, where each token
represents the ability to send one ICMP error message. Tokens are placed in the bucket at a
specified interval until the maximum allowed number of tokens is reached. For each error message
ICMP sends, a token is removed from the bucket. ICMP generates a series of error messages until
the bucket is empty. When the bucket is empty, further 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:
Brocade# show ipv6 cache
Total number of IPv6 and IPv6 VPN cache entries: 3
IPv6 Address Next Hop Interface
1 6000:: LOCAL ve 60
2 6000::2 LOCAL ve 60
3 fe80::768e:f8ff:fe2a:6200 LOCAL ve 60