262 CHAPTER 16: IP ROUTING PROTOCOL OPERATION
Perform the following configuration in Routing Protocol View.
By default, the routes discovered by other protocols will not be distributed.
In different routing protocol views, the parameter options are different. For details,
refer to the description of the import-route command for each protocol.
Defining IP Prefix
A prefix list is identified by the IP Prefix name. Each IP Prefix can include multiple
items, and each item can specify the matching range of the network prefix forms. The
index_number specifies the matching sequence in the prefix list.
Perform the following configurations in System View.
During the matching, the router checks list items identified by the index_number in
ascending order. If only one list item meets the condition, it means that it has passed
the ip-prefix filtering (and does not enter the testing of the next list item).
If more than one IP prefix item is defined, then the match mode of at least one list
item should be the permit mode. The list items of the deny mode can be defined to
rapidly filter the routing information not satisfying the requirement, but if all the
items are in the deny mode, no route will pass the ip-prefix filtering. You can
define an item of permit 0.0.0.0/0 greater-equal 0 less-equal 32 after the
multiple list items in the deny mode to let all the other routes pass.
Configuring the Filtering of Received Routes
Perform the following configuration in Routing Protocol View.
Define a policy that filters the routing information that does not satisfy the conditions
and receives routes with the help of an ACL or address prefix-list. The filter-policy
gateway command specifies that only the update packets from a specific neighboring
router will be received.
Table256 Configuring to import the routes of other protocols
Operation Command
Import routes of other protocols import-route protocol [ cost cost ] [ tag
value ] type { 1 | 2 } [ route-policy
route_policy_name ]
Do not import routes of other
protocols undo import-route protocol
Table257 Defining Prefix-list
Operation Command
Define a Prefix-list ip ip-prefix ip_prefix_name [ index index_number ] {
permit | deny } network len [ greater-equal
greater_equal ] [ less-equal less_equal ]
Remove a Prefix-list undo ip ip-prefix ip_prefix_name [ index
index_number | permit | deny ]