Specifications

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3-23
Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, Release 5.0(3)U2(2)
OL-25782-02
Chapter 3 Configuring OSPFv2
Configuring Advanced OSPFv2
Configuring Filter Lists for Border Routers
You can separate your OSPFv2 domain into a series of areas that contain related networks. All areas
must connect to the backbone area through an area border router (ABR). OSPFv2 domains can connect
to external domains as well, through an autonomous system border router (ASBR). See the “Areas”
section on page 3-4.
ABRs have the following optional configuration parameters:
• Area range—Configures route summarization between areas.
• Filter list—Filters the Network Summary (type 3) LSAs on an ABR that are allowed in from an
external area.
ASBRs also support filter lists.
BEFORE YOU BEGIN
Ensure that you have enabled the OSPF feature (see the “Enabling the OSPFv2 Feature” section on
page 3-13).
Create the route map that the filter list uses to filter IP prefixes in incoming or outgoing Network
Summary (type 3) LSAs. See Chapter 13, “Configuring Route Policy Manager.”
SUMMARY STEPS
1. configure terminal
2. router ospf instance-tag
3. area area-id filter-list route-map map-name {in | out}
4. (Optional) show ip ospf policy statistics
5. (Optional) copy running-config startup-config
DETAILED STEPS
Command Purpose
Step 1
configure terminal
Example:
switch# configure terminal
switch(config)#
Enters configuration mode.
Step 2
router ospf instance-tag
Example:
switch(config)# router ospf 201
switch(config-router)#
Creates a new OSPFv2 instance with the configured
instance tag.
Step 3
area area-id filter-list route-map
map-name {in | out}
Example:
switch(config-router)# area 0.0.0.10
filter-list route-map FilterLSAs in
Filters incoming or outgoing Network Summary (type
3) LSAs on an ABR.