Redistribute Routes into IS-IS
In this example, the configuration causes OSPF routes to be imported into the IS-IS routing table, and advertised into the ABC instance.
Topology
Figure 6-43: Redistribute Routes Into IS-IS
Configuration
R1
(config)#interface eth1 | Enter interface mode. |
(config-if)#ip router isis ABC | Enable IS-IS routing on an interface for area 49 (ABC). |
(config)#ip address 21.21.21.2/24 | Configure IP address on interface. |
(config-if)#exit | Exit interface mode. |
(config)#router isis ABC | Create an IS-IS routing instance for area 49 (ABC). |
(config-router)#is-type level-2-only | Configure instance as level-2-only routing. |
(config-router)#net 49.0000.0000.0001.00 | Set a Network Entity Title for this instance, specifying the area address and the system ID. |
(config-router)#dynamic-hostname | Configure the hostname to be advertised for an ISIS instance. |
R2
(config)#interface eth1 | Enter interface mode. |
(config)#ip address 21.21.21.1/24 | Configure IP address on interface. |
(config-if)#ip router isis ABC | Enable IS-IS routing on an interface for area 49 (ABC). |
(config-if)#exit | Exit interface mode. |
(config)#interface eth2 | Enter interface mode. |
(config)#ip address 31.31.31.1/24 | Configure IP address on interface. |
(config-if)#exit | Exit interface mode. |
(config)#router isis ABC | Create an IS-IS routing instance for area 49 (ABC). |
(config-router)#is-type level-2-only | Configure instance as level-2-only routing. |
(config-router)#net 49.0000.0000.0002.00 | Set a Network Entity Title for this instance, specifying the area address and the system ID. |
(config-router)#redistribute ospf | Specify redistributing routes from other routing protocol (OSPF) into IS-IS. |
(config-router)#dynamic-hostname | Configure the hostname to be advertised for an ISIS instance. |
(config-router)#exit | Exit interface mode. |
(config)#interface lo | Configure interface lo |
(config-if)#ip address 2.2.2.2/32 secondary | Configure secondary IP address to loopback interface |
(config-if)#exit | Exit interface mode. |
(config)#router ospf 100 | Configure OSPF routing process and specify the tag (100) which uniquely identifies the routing process |
(config-router)#ospf router-id 2.2.2.2 | Specify a Router ID (2.2.2.2) for the OSPF routing process. |
(config-router)#network 2.2.2.2/32 area 0.0.0.0 | Advertising 2.2.2.2 network |
(config-router)#network 31.31.31.0/24 area 0.0.0.0 | Advertising 31 network |
(config-router)#exit | Exit router mode. |
R3
(config)#interface eth2 | Enter interface mode. |
(config)#ip address 31.31.31.2/24 | Configure IP address on interface. |
(config-if)#exit | Exit interface mode. |
(config)#interface lo | Configure interface lo |
(config-if)#ip address 3.3.3.3/32 secondary | Configure secondary IP address to loopback interface |
(config-if)#exit | Exit interface mode. |
(config)#router ospf 100 | Configure OSPF routing process and specify the tag (100) which uniquely identifies the routing process |
(config-router)#ospf router-id 3.3.3.3 | Specify a Router ID (3.3.3.3) for the OSPF routing process. |
(config-router)#network 3.3.3.3/32 area 0.0.0.0 | Advertising 3.3.3.3 network |
(config-router)#network 31.31.31.0/24 area 0.0.0.0 | Advertising 31 network |
Validation
R1#show clns neighbors
Total number of L1 adjacencies: 0
Total number of L2 adjacencies: 1
Total number of adjacencies: 1
Tag ABC: VRF : default
System Id Interface SNPA State Holdtime Type Protocol
R2 eth1 5254.002a.230a Up 25 L2 IS-IS
R2#show clns neighbors
Total number of L1 adjacencies: 0
Total number of L2 adjacencies: 1
Total number of adjacencies: 1
Tag ABC: VRF : default
System Id Interface SNPA State Holdtime Type Protocol
R1 eth1 5254.00dc.0b76 Up 6 L2 IS-IS
R1#show clns is-neighbors
Tag ABC: VRF : default
System Id Interface State Type Priority Circuit Id
R2 eth1 Up L2 64 0000.0000.0001.01
R2#show clns is-neighbors
Tag ABC: VRF : default
System Id Interface State Type Priority Circuit Id
R1 eth1 Up L2 64 0000.0000.0001.01
R1#show isis topology
Tag ABC: VRF : default
IS-IS paths to level-2 routers
System Id Metric Next-Hop Interface SNPA
R1 --
R2 10 R2 eth1 5254.002a.230a
R2#show isis topology
Tag ABC: VRF : default
IS-IS paths to level-2 routers
System Id Metric Next-Hop Interface SNPA
R1 10 R1 eth1 5254.00dc.0b76
R2 --
R1#show isis database
Tag ABC: VRF : default
IS-IS Level-2 Link State Database:
LSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
R1.00-00 * 0x00000003 0x2D63 1096 0/0/0
R1.01-00 * 0x00000002 0x1FBA 1096 0/0/0
R2.00-00 0x00000004 0xEF02 1108 0/0/0
R2#show isis database
Tag ABC: VRF : default
IS-IS Level-2 Link State Database:
LSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
R1.00-00 0x00000003 0x2D63 1021 0/0/0
R1.01-00 0x00000002 0x1FBA 1021 0/0/0
R2.00-00 * 0x00000004 0xEF02 1035 0/0/0
R1#show ip isis route
Codes: C - connected, E - external, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, D - discard, e - external metric
** - invalid
Tag ABC: VRF : default
Destination Metric Next-Hop Interface Tag
L2 2.2.2.2/32 10 21.21.21.1 eth1 0
L2 3.3.3.3/32 10 21.21.21.1 eth1 0
C 21.21.21.0/24 10 -- eth1 0
L2 31.31.31.0/24 10 21.21.21.1 eth1 0
R2#show ip isis route
Codes: C - connected, E - external, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, D - discard, e - external metric
** - invalid
Tag ABC: VRF : default
Destination Metric Next-Hop Interface Tag
E 2.2.2.2/32 0 -- -- 0
E 3.3.3.3/32 0 -- -- 0
C 21.21.21.0/24 10 -- eth1 0
E 31.31.31.0/24 0 -- -- 0
R1#show ip route
Codes: K - kernel, C - connected, S - static, R - RIP, B - BGP
O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2,
ia - IS-IS inter area, E - EVPN,
v - vrf leaked
* - candidate default
IP Route Table for VRF "default"
i L2 2.2.2.2/32 [115/10] via 21.21.21.1, eth1, 00:16:54
i L2 3.3.3.3/32 [115/10] via 21.21.21.1, eth1, 00:16:43
C 10.12.30.0/24 is directly connected, eth0, 00:24:28
C 21.21.21.0/24 is directly connected, eth1, 00:18:37
i L2 31.31.31.0/24 [115/10] via 21.21.21.1, eth1, 00:16:54
C 127.0.0.0/8 is directly connected, lo, 00:24:28
Gateway of last resort is not set
R2#show ip route
Codes: K - kernel, C - connected, S - static, R - RIP, B - BGP
O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2,
ia - IS-IS inter area, E - EVPN,
v - vrf leaked
* - candidate default
IP Route Table for VRF "default"
C 2.2.2.2/32 is directly connected, lo, 00:21:31
O 3.3.3.3/32 [110/2] via 31.31.31.2, eth2, 00:20:14
C 10.12.30.0/24 is directly connected, eth0, 00:27:36
C 21.21.21.0/24 is directly connected, eth1, 00:21:31
C 31.31.31.0/24 is directly connected, eth2, 00:21:31
C 127.0.0.0/8 is directly connected, lo, 00:27:36
Gateway of last resort is not set
R2#show ip ospf neighbor
Total number of full neighbors: 1
OSPF process 100 VRF(default):
Neighbor ID Pri State Dead Time Address Interface Instance ID
3.3.3.3 1 Full/Backup 00:00:35 31.31.31.2 eth2 0
R3#show ip ospf neighbor
Total number of full neighbors: 1
OSPF process 100 VRF(default):
Neighbor ID Pri State Dead Time Address Interface Instance ID
2.2.2.2 1 Full/DR 00:00:32 31.31.31.1 eth2 0
R2#show ip ospf route
OSPF process 100:
Codes: C - connected, D - Discard, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
OSPF LFA attributes:
P - Primary, SP - Secondary-Path, LP - Link Protecting,
NP - Node Protecting, BID - Broadcast Link Protecting
C 2.2.2.2/32 [1] is directly connected, lo, Area 0.0.0.0
O 3.3.3.3/32 [2] via 31.31.31.2, eth2, Area 0.0.0.0
C 31.31.31.0/24 [1] is directly connected, eth2, Area 0.0.0.0
R3#show ip ospf route
OSPF process 100:
Codes: C - connected, D - Discard, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
OSPF LFA attributes:
P - Primary, SP - Secondary-Path, LP - Link Protecting,
NP - Node Protecting, BID - Broadcast Link Protecting
O 2.2.2.2/32 [2] via 31.31.31.1, eth2, Area 0.0.0.0
C 3.3.3.3/32 [1] is directly connected, lo, Area 0.0.0.0
C 31.31.31.0/24 [1] is directly connected, eth2, Area 0.0.0.0
R3#show ip route
Codes: K - kernel, C - connected, S - static, R - RIP, B - BGP
O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2,
ia - IS-IS inter area, E - EVPN,
v - vrf leaked
* - candidate default
IP Route Table for VRF "default"
O 2.2.2.2/32 [110/2] via 31.31.31.1, eth2, 00:19:47
C 3.3.3.3/32 is directly connected, lo, 00:20:40
C 10.12.30.0/24 is directly connected, eth0, 00:26:28
C 31.31.31.0/24 is directly connected, eth2, 00:20:40
C 127.0.0.0/8 is directly connected, lo, 00:26:28
Gateway of last resort is not set
Last modified date: 08/28/2023