3Com 5500-EI Series, Reference Manual

Page: 344 / 1314

4-30
System View: return to User View with Ctrl+Z.
[Sysname] acl number 2000
[Sysname-acl-basic-2000] rule 0 permit source 10.1.1.1 0.0.0.255
[Sysname-acl-basic-2000] quit
[Sysname] ospf
[Sysname-ospf-1] filter-policy 2000 export
filter-policy import
Syntax
filter-policy
{
acl-number
|
ip-prefix ip-prefix-name
|
gateway prefix-list-name
}
import
undo filter-policy
{
acl-number
|
ip-prefix ip-prefix-name
|
gateway ip-prefix-name
}
import
View
OSPF view
Parameters
acl-number
: Number of an ACL used to match destination addresses in routing information, in the
range 2000 to 3999.
ip-prefix-name
: Name of the IP prefix list used to match destination addresses in routing information, a
string of 1 to 19 characters.
gateway ip-prefix-name:
Name of an IP address prefix list used to filter routes based on the next hop of
the routing information, a string of 1 to 19 characters.
For details about IP prefix lists, refer to the section IP
Route Policy Configuration
.
Description
Use the
filter-policy import
command to configure the filtering of incoming routes.
Use the
undo filter-policy import
command to disable such filtering.
By default, no filtering of incoming routes is configured.
In some cases, it may be required that only the routing information meeting some conditions can be
received. You can use the
filter-policy import
command to set the matching rules for the routing
information to be received. Only the routing information matching the rules will be received.
The
filter-policy import
command only filters the routes calculated with the SPF algorithm. Only the
routes passing the filtration can be added to the routing table.
OSPF is a dynamic routing protocol based on link state, with routing information contained in LSAs.
For the filtering of incoming routes, routes to be filtered are calculated by SPF and installed in the OSPF
routing table.
For the filtering of outing routes, denied LSAs will not be generated for advertisement.
Examples
# Reference ACL 2000 to filter incoming routing information.
<Sysname> system-view
System View: return to User View with Ctrl+Z.
[Sysname] acl ospf