1-4
Define an IPv6 prefix list
Identified by name, each IPv6 prefix list can comprise multiple items. Each item specifies a prefix range
to match and is identified by an index number.
An item with a smaller index number is matched first. If one item is matched, the IPv6 prefix list is
passed, and the routing information will not go to the next item.
Follow these steps to define an IPv6 prefix list:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Define an IPv6 prefix
list
ip ipv6-prefix ipv6-prefix-name
[
index
index-number
] {
deny
|
permit
}
ipv6-address
prefix-length
[
greater-equal min-prefix-length
]
[
less-equal max-prefix-length
]
Required
Not defined by default.
If all items are set to the
deny
mode, no routes can pass the IPv6 prefix list. Therefore, you need to
define the
permit
:: 0
less-equal
128 item following multiple
deny
items to allow other IPv6 routing
information to pass.
For example, the following configuration filters routes 2000:1::/48, 2000:2::/48 and 2000:3::/48, but
allows other routes to pass.
<Sysname> system-view
[Sysname] ip ipv6-prefix abc index 10 deny 2000:1:: 48
[Sysname] ip ipv6-prefix abc index 20 deny 2000:2:: 48
[Sysname] ip ipv6-prefix abc index 30 deny 2000:3:: 16
[Sysname] ip ipv6-prefix abc index 40 permit :: 0 less-equal 128
Configuring a Route Policy
A route policy is used to filter routing information, and modify attributes of matching routing information.
The match criteria of a route policy can be configured by referencing filters above mentioned.
A route policy can comprise multiple nodes, and each route policy node contains:
z
if-match
clauses: Define the match criteria that routing information must satisfy. The matching
objects are some attributes of routing information.
z
apply
clauses: Specify the actions to be taken on routing information that has satisfied the match
criteria, such as route attribute modification.
Prerequisites
Before configuring this task, you need to configure:
z
Filters
z
Routing protocols
You also need to decide on:
