Multi-Service IronWare Routing Configuration Guide
Multi-Service IronWare Routing Configuration Guide
R05.5.00c
Part Number: 53-1002821-02
documentation@brocade.com


IPv6 Prefix List : Configuring an IPv6 prefix list

Configuring an IPv6 prefix list
Brocade devices support IPv6 prefix lists, which you can use for basic traffic filtering. You can configure up to 100 IPv6 prefix lists.
An IPv6 prefix list is composed of one or more conditional statements that pose an action (permit or deny) if a packet matches a specified prefix. In prefix lists with multiple statements, you can specify a sequence number for each statement. The specified sequence number determines the order in which the statement appears in the prefix.
You can configure an IPv6 prefix list on a global basis, then use it as input to other commands or processes, such as route aggregation, route redistribution, route distribution, route maps, and so on. When a Brocade device interface sends or receives an IPv6 packet, it applies the statements within the IPv6 prefix list in their order of appearance to the packet. As soon as a match occurs, the device takes the specified action (permit or deny the packet) and stops further comparison for that packet.
You can use permit statements in the prefix list to specify the traffic that you want to send to the other feature. If you use deny statements, the traffic specified by the deny statements is not supplied to the other feature.
To configure an IPv6 prefix list and use it as input to the RIPng distribute-list command, enter commands such as the following.
Brocade(config)# ipv6 prefix-list routesfor2001 permit 2001:db8::/32
Brocade(config)# ipv6 router rip
Brocade(config-ripng-router)# distribute-list prefix-list routesfor2001 out ethernet 3/1
 
These commands permit the inclusion of routes with the IPv6 prefix 2001:db8::/32 in RIPng routing updates sent from Ethernet interface 3/1.
Syntax:
[no] ipv6 prefix-list name [seq sequence-number] deny ipv6-prefix/prefix-length | permit ipv6-prefix/prefix-length | description string [ge ge-value] [le le-value]
The name parameter specifies the prefix list name. You use this name when using the prefix list as input to command or route map.
The seq seq-number parameter is optional and specifies the IPv6 prefix list’s sequence number. If you do not specify a sequence number, the software numbers them in increments of 5, beginning with prefix list entry 5. The Brocade device interprets the prefix list entries in numerical order, beginning with the lowest sequence number.
The description string parameter is a text string describing the prefix list.
The deny ipv6-prefix/prefix-length | permit ipv6-prefix/prefix-length parameters specify the action the Brocade device takes if a packet contains a route specified in this prefix list.
You must specify the ipv6-prefix parameter in hexadecimal using 16-bit values between colons as documented in RFC 2373.
You must specify the prefix-length parameter as a decimal value. A slash mark (/) must follow the ipv6-prefix parameter and precede the prefix-length parameter.
The prefix list matches only on the specified prefix/prefix length unless you use the ge prefix-length or le prefix-length parameters. (See below.)
You can specify a range of prefix lengths for prefixes that are more specific than ipv6-prefix/prefix-length.
If you specify only ge ge-value, then the range is from ge-value to 128.
If you specify only le le-value, then the range is from le-value to the prefix-length parameter.
The ge-value or le-value you specify must meet the following condition.
prefix-length < ge-value <= le-value <= 128
If you do not specify ge ge-value or le le-value, the prefix list matches only on the exact prefix you specify with the ipv6-prefix/prefix-length parameter.
To delete the prefix list entry, use the no form of this command.

IPv6 Prefix List : Configuring an IPv6 prefix list