There have been conditions whereby we see that in OSPF exterior/NSSA exterior routes are usually not in a position to set up attributable to forwarding tackle is just not within the routing desk as intra O or inter-area OIA route. So we’ve to configure the community in a method that both we’ve the route by way of O or OIA to put in that exterior route within the routing desk.
Nevertheless if in some nook instances buyer can’t make modifications to accommodate the above and should have the forwarding tackle from another supply.
Step-by-step Resolution to put in exterior routes
On this scenario we are able to use a command local-rib-criteria forwarding-address which is able to solely verify the OSPF rib and never international rib to put in the route within the routing desk.
Observe: OSPF solely provides the forwarding tackle if the next-hop of the route is in OSPF and never as an exterior route else it should set the forwarding tackle to the interface on which peering is configured.
First take a look at the habits with out utilizing the command
R2#sh run | sec router ospf
router ospf 1
router-id 2.2.2.2
space 1 nssa no-summary
community 172.168.1.1 0.0.0.0 space 0
community 192.168.1.2 0.0.0.0 space 1
community 192.168.24.2 0.0.0.0 space 0
R2#sh ip ospf database nssa-external
OSPF Router with ID (2.2.2.2) (Course of ID 1)
Kind-7 AS Exterior Hyperlink States (Space 1)
LS age: 320
Choices: (No TOS-capability, Kind 7/5 translation, DC, Upward)
LS Kind: AS Exterior Hyperlink
Hyperlink State ID: 155.55.55.87 (Exterior Community Quantity )
Promoting Router: 1.1.1.1
LS Seq Quantity: 80000002
Checksum: 0xC855
Size: 36
Community Masks: /32
Metric Kind: 2 (Bigger than any hyperlink state path)
MTID: 0
Metric: 20
Ahead Deal with: 10.1.1.6
Exterior Route Tag: 0
R2#sh ip route 10.1.1.6
Routing entry for 10.1.1.6/32
Identified by way of “static”, distance 1, metric 0
Routing Descriptor Blocks:
* 192.168.1.1
Route metric is 0, visitors share rely is 1
R2#sh ip route 155.55.55.87
% Community not in desk
Let’s configure the local-rib command for forwarding tackle and see the habits:
R2#sh run | sec router
router ospf 1
local-rib-criteria forwarding-address
R2#sh ip ospf database nssa-external
OSPF Router with ID (2.2.2.2) (Course of ID 1)
Kind-7 AS Exterior Hyperlink States (Space 1)
Routing Bit Set on this LSA in topology Base with MTID 0
LS age: 117
Choices: (No TOS-capability, Kind 7/5 translation, DC, Upward)
LS Kind: AS Exterior Hyperlink
Hyperlink State ID: 155.55.55.87 (Exterior Community Quantity )
Promoting Router: 1.1.1.1
LS Seq Quantity: 80000002
Checksum: 0xC855
Size: 36
Community Masks: /32
Metric Kind: 2 (Bigger than any hyperlink state path)
MTID: 0
Metric: 20
Ahead Deal with: 10.1.1.6
Exterior Route Tag: 0
R2#sh ip route 10.1.1.6
Routing entry for 10.1.1.6/32
Identified by way of “static”, distance 1, metric 0
Routing Descriptor Blocks:
* 192.168.1.1
Route metric is 0, visitors share rely is 1
R2#sh ip route 155.55.55.87
Routing entry for 155.55.55.87/32
Identified by way of “ospf 1”, distance 110, metric 20, sort NSSA extern 2, ahead metric 20
Final replace from 192.168.1.1 on Ethernet0/0, 00:04:44 in the past
Routing Descriptor Blocks:
* 192.168.1.1, from 1.1.1.1, 00:04:44 in the past, by way of Ethernet0/0
Route metric is 20, visitors share rely is 1
If we’ve the route within the routing desk from OSPF however as an exterior route then this command won’t work because the situation to put in the route has not met, this command is simply altering the default international routing desk lookup to happen on the OSPF native rib. Relaxation all situation should match.
Proceed Studying:
Perceive & Configure OSPF SHAM LINKS
How one can configure OSPF Digital Hyperlink?
OSPF Multi-Space Adjacency : Instance State of affairs
