Filter-Policy Import - 3Com 8807 Command Reference Manual

440 C 25: OSPF C C
HAPTER ONFIGURATION OMMANDS
the filtering conditions for the routing information to be received. Only the routing
information passing the filtration can be received.
The filter-policy import command is used to filter the routes calculated by OSPF.
Only the routes that pass the filter are added into the routing table. The command
can filter the routes by next hop or by destination address.
Because OSPF is a link state-based dynamic routing protocol, its routing
information is hidden in LSAs. OSPF, however, cannot filter advertised and received
LSAs. Compared with the case with vector-based routing protocols, the use of this
command is rather limited with OSPF.
Example
# Filter the received routing information according to the rule defined by the
access control list 2000.
[SW8800] acl number 2000
[3Com-acl-basic-2000] rule permit source 20.0.0.0 0.255.255.255
[3Com-acl-basic-2000] rule deny source any
[3Com-ospf-1] filter-policy 2000 import

filter-policy import

Syntax
filter-policy { acl-number | ip-prefix ip-prefix-name } import
undo filter-policy { acl-number | ip-prefix ip-prefix-name } import
View
OSPF area view
Parameter
acl-number: Specifies the number of the basic or advanced ACL used for filtering
Type-3 LSAs.
ip-prefix-name: Specifies the name of the address prefix list used for filtering
Type-3 LSAs.
Description
Use the filter-policy import command to set the filter condition for the Type-3
LSAs received by an OSPF area.
Use the undo filter-policy import command to cancel the set filter condition.
By default, no received Type-3 LSA is filtered.
In some situations, it may be required that only some Type-3 LSAs meeting a
certain condition be received. In this case, you can define a Filter-policy to set the
filter condition for received Type-3 LSAs so that only the Type-3 LSAs having
passed the filtration can be received.
Use the filter-policy import command to filter the Type-3 LSAs generated locally
in an OSPF area so that only those Type-3 LSAs having passed the filtration can be
added into the link state database of the other areas. The filtration is implemented
according to the link state ID of the Type-3 LSAs.