Route redistribution configuration [step by step]

Route redistribution configuration [step by step]

 

Topology:

In this tutorial, we will redistribute a static route into OSPF.

Steps:

1/ Between R1 and R2, static routing is configured (R1 have static route to 3.3.3.3).

2/ OSPF adjacency between R2 and R3. (Lo1 : 3.3.3.3 advertised into ospf)

3/ Redsitribute static route subnet into OSPF process

==> R3 will have 1.1.1.1 as external route in its routing table, connectivity between Loopbacks in R1 and R3.

R1 config:

R1#

!

version 15.2

!

hostname R1

!

interface Loopback1

ip address 1.1.1.1 255.255.255.255

!

interface Ethernet0/0

no ip address

shutdown

duplex auto

!

interface GigabitEthernet0/0

ip address 172.16.0.1 255.255.255.252

media-type gbic

speed 1000

duplex full

negotiation auto

ip route 3.3.3.3 255.255.255.255 172.16.0.2

ip route 172.17.0.0 255.255.255.252 172.16.0.2

routing table R1:

R1#sh ip route

Codes: L – local, C – connected, S – static, R – RIP, M – mobile, B – BGP

D – EIGRP, EX – EIGRP external, 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, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2

ia – IS-IS inter area, * – candidate default, U – per-user static route

o – ODR, P – periodic downloaded static route, H – NHRP, l – LISP

+ – replicated route, % – next hop override

Gateway of last resort is not set

1.0.0.0/32 is subnetted, 1 subnets

C 1.1.1.1 is directly connected, Loopback1

3.0.0.0/32 is subnetted, 1 subnets

S 3.3.3.3 [1/0] via 172.16.0.2

172.16.0.0/16 is variably subnetted, 2 subnets, 2 masks

C 172.16.0.0/30 is directly connected, GigabitEthernet0/0

L 172.16.0.1/32 is directly connected, GigabitEthernet0/0

172.17.0.0/30 is subnetted, 1 subnets

S 172.17.0.0 [1/0] via 172.16.0.2

R2 configuration:

R2#

interface Loopback0

ip address 2.2.2.2 255.255.255.0

!

interface GigabitEthernet0/0

ip address 172.16.0.2 255.255.255.252

media-type gbic

speed 1000

duplex full

negotiation auto

!

interface GigabitEthernet1/0

ip address 172.17.0.1 255.255.255.252

negotiation auto

!

router ospf 10

redistribute connected subnets

redistribute static subnets

network 172.17.0.0 0.0.0.3 area 0

!

ip forward-protocol nd

!

!

no ip http server

no ip http secure-server

ip route 1.1.1.1 255.255.255.255 172.16.0.1

R2 routing table:

R2#sh ip route

Codes: L – local, C – connected, S – static, R – RIP, M – mobile, B – BGP

D – EIGRP, EX – EIGRP external, 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, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2

ia – IS-IS inter area, * – candidate default, U – per-user static route

o – ODR, P – periodic downloaded static route, H – NHRP, l – LISP

+ – replicated route, % – next hop override

Gateway of last resort is not set

1.0.0.0/32 is subnetted, 1 subnets

S 1.1.1.1 [1/0] via 172.16.0.1

2.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C 2.2.2.0/24 is directly connected, Loopback0

L 2.2.2.2/32 is directly connected, Loopback0

3.0.0.0/32 is subnetted, 1 subnets

O 3.3.3.3 [110/2] via 172.17.0.2, 01:22:37, GigabitEthernet1/0

172.16.0.0/16 is variably subnetted, 2 subnets, 2 masks

C 172.16.0.0/30 is directly connected, GigabitEthernet0/0

L 172.16.0.2/32 is directly connected, GigabitEthernet0/0

172.17.0.0/16 is variably subnetted, 2 subnets, 2 masks

C 172.17.0.0/30 is directly connected, GigabitEthernet1/0

L 172.17.0.1/32 is directly connected, GigabitEthernet1/0

R2#

R3 configuration:

interface Loopback1

ip address 3.3.3.3 255.255.255.255

!

interface Ethernet0/0

no ip address

shutdown

duplex auto

!

interface GigabitEthernet0/0

ip address 172.17.0.2 255.255.255.252

media-type gbic

speed 1000

duplex full

negotiation auto

!

interface GigabitEthernet1/0

no ip address

shutdown

negotiation auto

!

router ospf 10

network 3.3.3.3 0.0.0.0 area 0

network 172.17.0.0 0.0.0.3 area 0

!

R3 routing table:

R3#sh ip route

Codes: L – local, C – connected, S – static, R – RIP, M – mobile, B – BGP

D – EIGRP, EX – EIGRP external, 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, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2

ia – IS-IS inter area, * – candidate default, U – per-user static route

o – ODR, P – periodic downloaded static route, H – NHRP, l – LISP

+ – replicated route, % – next hop override

Gateway of last resort is not set

1.0.0.0/32 is subnetted, 1 subnets

O E2 1.1.1.1 [110/20] via 172.17.0.1, 01:11:43, GigabitEthernet0/0

2.0.0.0/24 is subnetted, 1 subnets

O E2 2.2.2.0 [110/20] via 172.17.0.1, 00:00:54, GigabitEthernet0/0

3.0.0.0/32 is subnetted, 1 subnets

C 3.3.3.3 is directly connected, Loopback1

172.16.0.0/30 is subnetted, 1 subnets

O E2 172.16.0.0 [110/20] via 172.17.0.1, 00:00:54, GigabitEthernet0/0

172.17.0.0/16 is variably subnetted, 2 subnets, 2 masks

C 172.17.0.0/30 is directly connected, GigabitEthernet0/0

L 172.17.0.2/32 is directly connected, GigabitEthernet0/0

Tests:

R1#ping 3.3.3.3 so lo1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds:

Packet sent with a source address of 1.1.1.1

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 56/68/88 ms

R1#ping 3.3.3.3

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 52/60/72 ms

R1#

————-

————-

R3#ping 1.1.1.1 so lo1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:

Packet sent with a source address of 3.3.3.3

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 60/72/104 ms

R3#ping 1.1.1.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 48/56/64 ms

R3#

Notes:

  • R2 have a static to 1.1.1.1 , this route is redistributed in OSPF process, so R3 will have an external route to R1’s LO1 (1.1.1.1)
  • redistribute connected needed in order to ping from R1 with the interface connected to R2 as source interface.
  • R1 must have a static route to 172.17.0.0/30 in order to ping from R3 gi0/0 interface (when pinging from R3 to R1 , the return traffic need that R1 knows 172.17.0.0/30 subnets in order to reach R3gi0/0). this is not needed when pinging from R3 with Lo1(3.3.3.3) as source interface.

Done! (Bol)

Bilel-A

Enthusiastic Network Engineer specializing in Cisco ACI, passionate about solving challenges. A lifelong learner who loves gaining and sharing knowledge. Profile: https://www.linkedin.com/in/bilel-ameur-71116b2b5
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