What is OSPF Sham Links? how to configure OSPF Sham Links?

OSPF Sham Links are required when we try to use a backdoor link between two CE routers in MPLS VPN PE CE scenarios.What is OSPF sham link ? OSPF Sham links is a logical inter-area link carried by the super backbone. A Sham links is required only between two VPN sites that belong to the same area and have a backdoor link for backup purposes. OSPF adjacency is established across the sham link. what is BGP ? what is BGP ? what is EIGRP? what is RIPv2? what is MPLS? what is MPLS LDP ? what is MPLS L3 VPN? How to configure MPLS L3 VPN with RIPv2 ? How to configure MPLS L3 VPN with EIGRP ?



OSPF Sham Links are required when we try to use a backdoor link between two CE routers in MPLS VPN PE CE scenarios.






What is OSPF sham link ?
OSPF Sham links is a logical inter-area link carried by the super backbone. A Sham links is required only between two VPN sites that belong to the same area and have a backdoor link for backup purposes. OSPF adjacency is established across the sham link.  





lets see the configuration for better understanding:-

Topology:-
OSPF Sham Links are required when we try to use a backdoor link between two CE routers in MPLS VPN PE CE scenarios.

Goal:

  • configure the topology as per the diagram 
  • assign the IP addresses to their interfaces
  • configure IGP (OSPF 1) inside MPLS SP core 
  • configure MPLS LDP on router 1_2_3 
  • configure labels (99-199_200-299_300-399)
  • configure VRF A-1 on router 1 and VRF A-2 on router 3
  • configure RD and RT  value 500:1 on both the sites
  • configure on router 1 assign fastethernet facing CE under VRF A-1
  • configure on router 3 assign fastethernet facing CE under VRF A-2
  • Configure the loopbacks with exact mask to exchange the routes 
  • configure OSPF 1 on both CE routers  
  • configure OSPF 11 on PE router 1 under VRF A-1 and OSPF 13 on PE router 3 under VRF A-2
  •  make sure PE and CE routers can ping 



  • configure VPNv4 peering between PE routers. 
  • Configure redistribution on PE routers between OSPF and BGP under VRF.
  • make sure both the  CEs routers able to ping.
  • Configure one serial link (backup link /backdoor) between router 4/5.
  • Configure router1 and router 3 in area 0 to ensure that OSPF routes learned other end should prefer MPLS backbone. 



R1(config)#Interface fastethernet 0/0
R1(config-if)#Ip address 10.1.1.1   255.0.0.0
R1(config-if)#No shutdown
R1(config-if)# keepalive
R1(config-if)#Exit


R1(config)#Interface serial 4/0
R1(config-if)#Ip address  1.1.1.1 255.0.0.0
R1(config-if)#No shutdown
R1(config-if)#Exit

R1(config)#Interface serial 4/2
R1(config-if)#Ip address  3.3.3.2 255.0.0.0
R1(config-if)#No shutdown
R1(config-if)#Exit

R1(config)#Interface loopback 0
R1(config-if)#Ip address 192.168.10.1 255.255.255.0
R1(config-if)#Exit

R1(config)#Interface loopback  1
R1(config-if)#Ip address 192.168.11.1 255.255.255.0
R1(config-if)#Exit
R1(config)#Interface loopback  2
R1(config-if)#Ip address 192.168.12.1 255.255.255.0
R1(config-if)#Exit
R1(config)#Interface loopback 3
R1(config-if)#Ip address 192.168.13.1  255.255.255.0
R1(config-if)#Exit

R2(config)#Interface fastethernet 0/0
R2(config-if)#Ip address 20.1.1.1   255.0.0.0
R2(config-if)#No shutdown
R2(config-if)#keepalive
R2(config-if)#Exit
R2(config)#Interface serial 4/0
R2(config-if)#Ip address  1.1.1.2 255.0.0.0
R2(config-if)#No shutdown
R2(config-if)#Exit

R2(config)#Interface serial 4/1
R2(config-if)#Ip address  2.2.2.1 255.0.0.0
R2(config-if)#No shutdown
R2(config-if)#Exit

R2(config)#Interface loopback 0
R2(config-if)#Ip address 192.168.20.1 255.255.255.0
R2(config-if)#Exit
R2(config)#Interface loopback  1
R2(config-if)#Ip address 192.168.21.1 255.255.255.0
R2(config-if)#Exit
R2(config)#Interface loopback  2
R2(config-if)#Ip address 192.168.22.1 255.255.255.0
R2(config-if)#Exit
R2(config)#Interface loopback 3
R2(config-if)#Ip address 192.168.23.1  255.255

R3(config)#Interface fastethernet 0/0
R3(config-if)#Ip address 30.1.1.1   255.0.0.0
R3(config-if)#No shutdown
R3(config-if)# keepalive
R3(config-if)#Exit


R3(config)#Interface serial 4/1
R3(config-if)#Ip address  2.2.2.2 255.0.0.0
R3(config-if)#No shutdown
R3(config-if)#Exit
R3(config)#Interface serial 4/2
R3(config-if)#Ip address  3.3.3.1 255.0.0.0
R3(config-if)#No shutdown
R3(config-if)#Exit

R3(config)#Interface loopback 0
R3(config-if)#Ip address 192.168.30.1 255.255.255.0
R3(config-if)#Exit
R3(config)#
R3(config)#Interface loopback  1
R3(config-if)#Ip address 192.168.31.1 255.255.255.0
R3(config-if)#Exit
R3(config)#Interface loopback  2
R3(config-if)#Ip address 192.168.32.1 255.255.255.0
R3(config-if)#Exit
R3(config)#Interface loopback 3
R3(config-if)#Ip address 192.168.33.1  255.255.
R3(config-if)#Exit

R4(config)#interface fastEthernet 0/0
R4(config-if)#ip address 30.1.1.2 255.0.0.0
R4(config-if)#no shutdown
R4(config-if)#exit

R4(config)#interface loopback 0
R4(config-if)#ip address 192.168.40.1 255.255.255.0
R4(config-if)#exit

R5(config)#Interface fastethernet 0/0
R5(config-if)#Ip address 10.1.1.2   255.0.0.0
R5(config-if)#shutdown
R5(config-if)#Exit

R5(config)#Interface loopback 0
R5(config-if)#Ip address 192.168.50.1  255.255.255.0
R5(config-if)#Exit


R1#show ip interface brief
Interface              IP-Address      OK? Method Status                Protocol
FastEthernet0/0        10.1.1.1        YES manual up                    up

Serial4/0              1.1.1.1         YES manual up                    up

Serial4/2              3.3.3.2         YES manual up                    up
Loopback0              192.168.10.1    YES manual up                    up
Loopback1              192.168.11.1    YES manual up                    up
Loopback2              192.168.12.1    YES manual up                    up
Loopback3              192.168.13.1    YES manual up                    up
R2#show ip interface brief
Interface              IP-Address      OK? Method Status                Protocol
FastEthernet0/0        20.1.1.1        YES manual up                    up
Serial4/0              1.1.1.2         YES manual up                    up
Serial4/1              2.2.2.1         YES manual up                    up
Loopback0              192.168.20.1    YES manual up                    up
Loopback1              192.168.21.1    YES manual up                    up
Loopback2              192.168.22.1    YES manual up                    up
Loopback3              192.168.23.1    YES manual up                    up

R3#show ip interface brief
Interface              IP-Address      OK? Method Status                Protocol
FastEthernet0/0        30.1.1.1        YES manual up                    up
Serial4/1              2.2.2.2         YES manual up                    up
Serial4/2              3.3.3.1         YES manual up                    up
Loopback0              192.168.30.1    YES manual up                    up
Loopback1              192.168.31.1    YES manual up                    up
Loopback2              192.168.32.1    YES manual up                    up
Loopback3              192.168.33.1    YES manual up                    up


R4#show ip interface brief
Interface              IP-Address      OK? Method Status                Protocol
FastEthernet0/0        30.1.1.2        YES manual up                    up
Loopback0              192.168.40.1    YES manual up                    up


R5#show ip interface  brief
Interface              IP-Address      OK? Method Status                Protocol
FastEthernet0/0        10.1.1.2        YES manual up                    up
Loopback0              192.168.50.1    YES manual up                    up

R1(config)#router ospf 1
R1(config-router)#network 1.0.0.0 0.255.255.255 area 0
R1(config-router)#network 3.0.0.0 0.255.255.255 area 0
R1(config-router)#network 192.168.10.0 255.0.0.0 area 0
R1(config-router)#network 192.168.11.0 255.0.0.0 area 0
R1(config-router)#network 192.168.12.0 255.0.0.0 area 0
R1(config-router)#network 192.168.13.0 255.0.0.0 area 0
R1(config-router)#end

R2(config)#router ospf 1
R2(config-router)#network 20.0.0.0 0.255.255.255 area 0
R2(config-router)#network 1.0.0.0 0.255.255.255 area 0
R2(config-router)#network 2.0.0.0 0.255.255.255 area 0
R2(config-router)#network 192.168.20.0 255.0.0.0 area 0
R2(config-router)#network 192.168.21.0 255.0.0.0 area 0
R2(config-router)#network 192.168.22.0 255.0.0.0 area 0
R2(config-router)#network 192.168.23.0 255.0.0.0 area 0
R2(config-router)#end

R3(config)#router ospf 1
R3(config-router)#network 2.0.0.0 0.255.255.255 area 0
R3(config-router)#network 3.0.0.0 0.255.255.255 area 0
R3(config-router)#network 192.168.30.0 255.0.0.0 area 0
R3(config-router)#network 192.168.31.0 255.0.0.0 area 0
R3(config-router)#network 192.168.32.0 255.0.0.0 area 0
R3(config-router)#network 192.168.33.0 255.0.0.0 area 0
R3(config-router)#end


R1#show ip route ospf
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

O     2.0.0.0/8 [110/128] via 3.3.3.1, 01:14:38, Serial4/2
                [110/128] via 1.1.1.2, 01:14:38, Serial4/0
O     20.0.0.0/8 [110/65] via 1.1.1.2, 01:14:38, Serial4/0
      192.168.20.0/32 is subnetted, 1 subnets
O        192.168.20.1 [110/65] via 1.1.1.2, 01:14:38, Serial4/0
      192.168.21.0/32 is subnetted, 1 subnets
O        192.168.21.1 [110/65] via 1.1.1.2, 01:14:38, Serial4/0
      192.168.22.0/32 is subnetted, 1 subnets
O        192.168.22.1 [110/65] via 1.1.1.2, 01:14:38, Serial4/0
      192.168.23.0/32 is subnetted, 1 subnets
O        192.168.23.1 [110/65] via 1.1.1.2, 01:14:38, Serial4/0
O     192.168.30.0/24 [110/65] via 3.3.3.1, 01:14:38, Serial4/2
      192.168.31.0/32 is subnetted, 1 subnets
O        192.168.31.1 [110/65] via 3.3.3.1, 01:14:38, Serial4/2
      192.168.32.0/32 is subnetted, 1 subnets
O        192.168.32.1 [110/65] via 3.3.3.1, 01:14:38, Serial4/2
      192.168.33.0/32 is subnetted, 1 subnets
O        192.168.33.1 [110/65] via 3.3.3.1, 01:14:38, Serial4/2

R3#show ip route ospf
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

O     1.0.0.0/8 [110/128] via 3.3.3.2, 01:18:05, Serial4/2
                [110/128] via 2.2.2.1, 01:18:05, Serial4/1
O     20.0.0.0/8 [110/65] via 2.2.2.1, 01:18:05, Serial4/1
O     192.168.10.0/24 [110/65] via 3.3.3.2, 01:18:05, Serial4/2
      192.168.11.0/32 is subnetted, 1 subnets
O        192.168.11.1 [110/65] via 3.3.3.2, 01:18:05, Serial4/2
      192.168.12.0/32 is subnetted, 1 subnets
O        192.168.12.1 [110/65] via 3.3.3.2, 01:18:05, Serial4/2
      192.168.13.0/32 is subnetted, 1 subnets
O        192.168.13.1 [110/65] via 3.3.3.2, 01:18:05, Serial4/2
      192.168.20.0/32 is subnetted, 1 subnets
O        192.168.20.1 [110/65] via 2.2.2.1, 01:18:05, Serial4/1
      192.168.21.0/32 is subnetted, 1 subnets
O        192.168.21.1 [110/65] via 2.2.2.1, 01:18:05, Serial4/1
      192.168.22.0/32 is subnetted, 1 subnets
O        192.168.22.1 [110/65] via 2.2.2.1, 01:18:05, Serial4/1
      192.168.23.0/32 is subnetted, 1 subnets
O        192.168.23.1 [110/65] via 2.2.2.1, 01:18:05, Serial4/1


R1(config)#mpls label protocol ldp
R1(config)#mpls label range 99 199
R1(config)#mpls ldp router-id loopback 0
R1(config)#exit

R1(config)#interface serial 4/0
R1(config-if)#mpls ip
R1(config-if)#exit

R1(config)#interface serial 4/2
R1(config-if)#mpls ip
R1(config-if)#exit

R2(config)#mpls label protocol ldp
R2(config)#mpls label range 200 299
R2(config)#mpls ldp router-id loopback 0
R2(config)#exit

R2(config)#interface serial 4/0
R2(config-if)#mpls ip
R2(config-if)#exit

R2(config)#interface serial 4/1
R2(config-if)#mpls ip
R2(config-if)#exit


R3(config)#mpls label protocol ldp
R3(config)#mpls label range 300 399
R3(config)#mpls ldp router-id loopback 0
R3(config)#exit

R3(config)#interface serial 4/1
R3(config-if)#mpls ip
R3(config-if)#exit


R3(config)#interface serial 4/2
R3(config-if)#mpls ip
R3(config-if)#exit

R1#show mpls ldp neighbor
    Peer LDP Ident: 192.168.20.1:0; Local LDP Ident 192.168.10.1:0
        TCP connection: 192.168.20.1.41723 - 192.168.10.1.646
        State: Oper; Msgs sent/rcvd: 190/188; Downstream
        Up time: 02:23:12
        LDP discovery sources:
          Serial4/0, Src IP addr: 1.1.1.2
        Addresses bound to peer LDP Ident:
          20.1.1.1        1.1.1.2         2.2.2.1         192.168.20.1
          192.168.21.1    192.168.22.1    192.168.23.1
    Peer LDP Ident: 192.168.30.1:0; Local LDP Ident 192.168.10.1:0
        TCP connection: 192.168.30.1.27403 - 192.168.10.1.646
        State: Oper; Msgs sent/rcvd: 186/184; Downstream
        Up time: 02:20:31
        LDP discovery sources:
          Serial4/2, Src IP addr: 3.3.3.1
        Addresses bound to peer LDP Ident:
          2.2.2.2         3.3.3.1         192.168.30.1    192.168.31.1
          192.168.32.1    192.168.33.1


R2#show mpls ldp neighbor
    Peer LDP Ident: 192.168.10.1:0; Local LDP Ident 192.168.20.1:0
        TCP connection: 192.168.10.1.646 - 192.168.20.1.41723
        State: Oper; Msgs sent/rcvd: 189/192; Downstream
        Up time: 02:24:22
        LDP discovery sources:
          Serial4/0, Src IP addr: 1.1.1.1
        Addresses bound to peer LDP Ident:
          1.1.1.1         3.3.3.2         192.168.10.1    192.168.11.1
          192.168.12.1    192.168.13.1
    Peer LDP Ident: 192.168.30.1:0; Local LDP Ident 192.168.20.1:0
        TCP connection: 192.168.30.1.64637 - 192.168.20.1.646
        State: Oper; Msgs sent/rcvd: 187/189; Downstream
        Up time: 02:22:00
        LDP discovery sources:
          Serial4/1, Src IP addr: 2.2.2.2
        Addresses bound to peer LDP Ident:
          2.2.2.2         3.3.3.1         192.168.30.1    192.168.31.1
          192.168.32.1    192.168.33.1

R3#show mpls ldp neighbor
    Peer LDP Ident: 192.168.20.1:0; Local LDP Ident 192.168.30.1:0
        TCP connection: 192.168.20.1.646 - 192.168.30.1.64637
        State: Oper; Msgs sent/rcvd: 190/188; Downstream
        Up time: 02:22:52
        LDP discovery sources:
          Serial4/1, Src IP addr: 2.2.2.1
        Addresses bound to peer LDP Ident:
          20.1.1.1        1.1.1.2         2.2.2.1         192.168.20.1
          192.168.21.1    192.168.22.1    192.168.23.1
    Peer LDP Ident: 192.168.10.1:0; Local LDP Ident 192.168.30.1:0
        TCP connection: 192.168.10.1.646 - 192.168.30.1.27403
        State: Oper; Msgs sent/rcvd: 187/189; Downstream
        Up time: 02:22:33
        LDP discovery sources:
          Serial4/2, Src IP addr: 3.3.3.2
        Addresses bound to peer LDP Ident:
          1.1.1.1         3.3.3.2         192.168.10.1    192.168.11.1
          192.168.12.1    192.168.13.1

R(config)#ip vrf A-1
R1(config-vrf)#rd 500:1
R1(config-vrf)#route-target import 500:1
R1(config-vrf)#route-target export 500:1
R1(config-vrf)#exit

R3(config)#ip vrf A-2
R3(config-vrf)#rd 500:1
R3(config-vrf)#route-target both 500:1
R3(config-vrf)#exit

R1(config)#interface fastethernet 0/0
R1(config-if)#ip vrf forwarding A-1

% Interface FastEthernet0/0 IPv4 disabled and address(es) removed due to enabling VRF A-1


R1(config-if)#ip address 10.1.1.1 255.0.0.0
R1(config-if)#no shutdown
R1(config-if)#exit

R3(config)#interface fastethernet 0/0
R3(config-if)#ip vrf forwarding A-2

% Interface FastEthernet0/0 IPv4 disabled and address(es) removed due to enabling VRF A-2

R3(config-if)#ip address 30.1.1.1 255.0.0.0
R3(config-if)#exit

R1#show run | section vrf
ip vrf A-1
 rd 500:1
 route-target export 500:1
 route-target import 500:1
 ip vrf forwarding A-1

R3#show run | section vrf
ip vrf A-2
 rd 500:1
 route-target export 500:1
 route-target import 500:1
 ip vrf forwarding A-2

R1(config)#interface loopback 0
R1(config-if)# ip ospf network point-to-point
R1(config-if)#end

R3(config)#interface loopback 0
R3(config-if)# ip ospf network point-to-point
R3(config-if)#end

R4(config)#router ospf 1
R4(config-router)#network 192.168.40.0 255.0.0.0 area 0
R4(config-router)#network 30.0.0.0 0.255.255.255 area 0
R4(config-router)#end

R1(config)#router ospf 11 vrf A-1
R1(config-router)#network 10.0.0.0 0.255.255.255 area 0
R1(config-router)#exit

*Mar 20 00:18:20.379: %OSPF-5-ADJCHG: Process 11, Nbr 192.168.40.1 on FastEthernet0/0 from LOADING to FULL, Loading Done



R1#show ip ospf 1 neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
192.168.33.1      0   FULL/  -        00:00:33    3.3.3.1         Serial4/2
192.168.23.1      0   FULL/  -        00:00:38    1.1.1.2         Serial4/0
R1#show ip ospf 11 neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
192.168.40.1      1   FULL/DR         00:00:33    10.1.1.2        FastEthernet0/0


R1#show ip route vrf A-1 ospf


Routing Table: A-1
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

      192.168.40.0/32 is subnetted, 1 subnets
O        192.168.40.1 [110/2] via 10.1.1.2, 00:01:43, FastEthernet0/0



R1#ping vrf A-1 192.168.40.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.40.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/46/100 ms



R5(config)#router ospf 1
R5(config-router)#network 192.168.50.0 255.0.0.0 area 0
R5(config-router)#network 10.0.0.0 0.255.255.255 area 0
R5(config-router)#end



R3(config)#router ospf 13 vrf A-2
R3(config-router)#network 30.0.0.0 0.255.255.255 area 0
R3(config-router)#end

*Mar 20 00:28:16.623: %OSPF-5-ADJCHG: Process 13, Nbr 192.168.50.1 on FastEthernet0/0 from LOADING to FULL, Loading Done

R3#show ip ospf 13 neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
192.168.50.1      1   FULL/DR         00:00:33    30.1.1.2        FastEthernet0/0


R3#show ip route vrf A-2 ospf

Routing Table: A-2
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

      192.168.50.0/32 is subnetted, 1 subnets
O        192.168.50.1 [110/2] via 30.1.1.2, 00:01:24, FastEthernet0/0


R1(config)#router bgp 6123
R1(config-router)#no bgp default ipv4-unicast
R1(config-router)#neighbor 192.168.30.1 remote-as 6123
R1(config-router)#neighbor 192.168.30.1 update-source loopback 0
R1(config-router)#address-family vpnv4 unicast
R1(config-router-af)#neighbor 192.168.30.1 activate
R1(config-router-af)#neighbor 192.168.30.1 send-community extended
R1(config-router-af)#neighbor 192.168.30.1 next-hop-self
R1(config-router-af)#end


R3(config)#router bgp 6123
R3(config-router)#no bgp default ipv4-unicast
R3(config-router)#neighbor 192.168.10.1 remote-as 6123
R3(config-router)#neighbor 192.168.10.1 update-source loopback 0
R3(config-router)#address-family vpnv4 unicast
R3(config-router-af)#neighbor 192.168.10.1 activate
R3(config-router-af)#neighbor 192.168.10.1 send-community extended
R3(config-router-af)#neighbor 192.168.10.1 next-hop-self
R3(config-router-af)#end

*Mar 20 00:59:36.259: %BGP-5-ADJCHANGE: neighbor 192.168.10.1 Up



R1(config)#router bgp 6123
R1(config-router)#address-family ipv4 vrf A-1
R1(config-router-af)#redistribute ospf 11 vrf A-1 match ?
  external       Redistribute OSPF external routes
  internal       Redistribute OSPF internal routes
  nssa-external  Redistribute OSPF NSSA external routes

R1(config-router-af)#redistribute ospf 11 vrf A-1 match internal ?
  external       Redistribute OSPF external routes
  metric         Metric for redistributed routes
  nssa-external  Redistribute OSPF NSSA external routes
  route-map      Route map reference
  <cr>

R1(config-router-af)#redistribute ospf 11 vrf A-1 match internal external ?
  1              Redistribute external type 1 routes
  2              Redistribute external type 2 routes
  metric         Metric for redistributed routes
  nssa-external  Redistribute OSPF NSSA external routes
  route-map      Route map reference
  <cr>

R1(config-router-af)#$e ospf 11 vrf A-1 match internal external 1 external 2
R1(config-router-af)#end



R1(config)#router ospf 11 vrf A-1
R1(config-router)#redistribute bgp 6123 subnets
R1(config-router)#end


R3(config)#router bgp 6123
R3(config-router)#address-family ipv4 vrf A-2
R3(config-router-af)#$e ospf 13 vrf A-2 match internal external 1 external 2
R3(config-router-af)#end

(R3(config-router-af)#redistribute ospf 13 vrf A-2 match internal external 1 external 2)


R3(config)#router ospf 13 vrf A-2
R3(config-router)#redistribute bgp 6123 subnets

R3(config-router)#end



R1#show ip bgp vpnv4 all
BGP table version is 7, local router ID is 192.168.13.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
              x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found


     Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 500:1 (default for vrf A-1)
 *>  10.0.0.0         0.0.0.0                  0         32768 ?
 *>i 30.0.0.0         192.168.30.1             0    100      0 ?
 *>  192.168.40.1/32  10.1.1.2                 2         32768 ?
 *>i 192.168.50.1/32  192.168.30.1             2    100      0 ?

R1#show ip route vrf A-1


Routing Table: A-1
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

      10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        10.0.0.0/8 is directly connected, FastEthernet0/0
L        10.1.1.1/32 is directly connected, FastEthernet0/0
B     30.0.0.0/8 [200/0] via 192.168.30.1, 00:05:57
      192.168.40.0/32 is subnetted, 1 subnets
O        192.168.40.1 [110/2] via 10.1.1.2, 00:40:55, FastEthernet0/0
      192.168.50.0/32 is subnetted, 1 subnets
B        192.168.50.1 [200/2] via 192.168.30.1, 00:05:57

R1#show ip route vrf A-1 bgp

Routing Table: A-1
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

B     30.0.0.0/8 [200/0] via 192.168.30.1, 00:06:24
      192.168.50.0/32 is subnetted, 1 subnets
B        192.168.50.1 [200/2] via 192.168.30.1, 00:06:24

R1#ping vrf A-1 192.168.40.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.40.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 44/72/104 ms


R1#ping vrf A-1 192.168.50.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.50.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 104/144/248 ms


R3#show ip bgp vpnv4 all
BGP table version is 7, local router ID is 192.168.33.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
              x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 500:1 (default for vrf A-2)
 *>i 10.0.0.0         192.168.10.1             0    100      0 ?
 *>  30.0.0.0         0.0.0.0                  0         32768 ?
 *>i 192.168.40.1/32  192.168.10.1             2    100      0 ?
 *>  192.168.50.1/32  30.1.1.2                 2         32768 ?


R3#show ip route vrf A-2

Routing Table: A-2
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

B     10.0.0.0/8 [200/0] via 192.168.10.1, 00:14:56
      30.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        30.0.0.0/8 is directly connected, FastEthernet0/0
L        30.1.1.1/32 is directly connected, FastEthernet0/0
      192.168.40.0/32 is subnetted, 1 subnets
B        192.168.40.1 [200/2] via 192.168.10.1, 00:14:56
      192.168.50.0/32 is subnetted, 1 subnets
O        192.168.50.1 [110/2] via 30.1.1.2, 00:22:01, FastEthernet0/0

R3#show ip route vrf A-2 BGP


Routing Table: A-2
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

B     10.0.0.0/8 [200/0] via 192.168.10.1, 00:15:15
      192.168.40.0/32 is subnetted, 1 subnets
B        192.168.40.1 [200/2] via 192.168.10.1, 00:15:15



R3#ping vrf A-2 192.168.50.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.50.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 44/76/132 ms

R3#ping vrf A-2 192.168.40.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.40.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 68/108/152 ms

R4#ping 192.168.50.1 source 192.168.40.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.50.1, timeout is 2 seconds:
Packet sent with a source address of 192.168.40.1
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 156/186/228 ms


R4#traceroute 192.168.50.1
Type escape sequence to abort.
Tracing the route to 192.168.50.1
VRF info: (vrf in name/id, vrf out name/id)
  1 10.1.1.1 108 msec 56 msec 104 msec
  2 30.1.1.1 [MPLS: Label 308 Exp 0] 84 msec 104 msec 104 msec
  3 30.1.1.2 172 msec 148 msec 128 msec

R5#ping 192.168.40.1 source 192.168.50.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.40.1, timeout is 2 seconds:
Packet sent with a source address of 192.168.50.1
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 140/156/180 ms

R5#traceroute 192.168.40.1
Type escape sequence to abort.
Tracing the route to 192.168.40.1
VRF info: (vrf in name/id, vrf out name/id)
  1 30.1.1.1 36 msec 76 msec 56 msec
  2 10.1.1.1 [MPLS: Label 104 Exp 0] 180 msec 168 msec 56 msec
  3 10.1.1.2 180 msec 172 msec 228 msec



R4#show ip route ospf
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

O E2  30.0.0.0/8 [110/1] via 10.1.1.1, 00:15:14, FastEthernet0/0
      192.168.50.0/32 is subnetted, 1 subnets
O E2     192.168.50.1 [110/2] via 10.1.1.1, 00:15:14, FastEthernet0/0


R5#show ip route ospf
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


O E2  10.0.0.0/8 [110/1] via 30.1.1.1, 00:12:07, FastEthernet0/0
      192.168.40.0/32 is subnetted, 1 subnets
O E2     192.168.40.1 [110/2] via 30.1.1.1, 00:12:07, FastEthernet0/0

R1(config)#interface loopback 11




R1(config-if)#ip vrf forwarding A-1

R1(config-if)#ip address 111.5.5.5 255.255.255.255
R1(config-if)#exit

R1(config)#router bgp 6123
R1(config-router)#address-family ipv4 vrf A-1
R1(config-router-af)#network 111.5.5.5 mask 255.255.255.255
R1(config-router-af)#exit

R1(config)#router OSPF
R1(config)#router ospf 11 vrf A-1
R1(config-router)#area 0 sham-link 111.5.5.5 111.6.6.6
R1(config-router)#exit

*Aug 12 00:42:45.387: %OSPF-5-ADJCHG: Process 11, Nbr 30.1.1.1 on OSPF_SL0 from LOADING to FULL, Loading Done

R3(config)#interface loopback 13
R3(config-if)#ip vrf forwarding A-2
R3(config-if)#ip address 111.6.6.6 255.255.255.255
R3(config-if)#exit

R3(config)#router bgp 6123
R3(config-router)#address-family ipv4 vrf A-2
R3(config-router-af)#network 111.6.6.6 mask 255.255.255.255
R3(config-router-af)#exit

R3(config-router)#exit

R3(config)#router ospf 13 vrf A-2
R3(config-router)#area 0 sham-link 111.6.6.6 111.5.5.5
R3(config-router)#end

*Aug 12 00:42:46.139: %OSPF-5-ADJCHG: Process 13, Nbr 10.1.1.1 on OSPF_SL0 from LOADING to FULL, Loading Done

R1#show ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
192.168.23.1      0   FULL/  -        00:00:30    1.1.1.2         Serial4/0
192.168.33.1      0   FULL/  -        00:00:32    3.3.3.1         Serial4/2
30.1.1.1          0   FULL/  -           -        111.6.6.6       OSPF_SL0
192.168.50.1      1   FULL/BDR        00:00:36    10.1.1.2        FastEthernet0/0


R3#show ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
192.168.13.1      0   FULL/  -        00:00:31    3.3.3.2         Serial4/2
192.168.23.1      0   FULL/  -        00:00:35    2.2.2.1         Serial4/1
10.1.1.1          0   FULL/  -           -        111.5.5.5       OSPF_SL0
192.168.40.1      1   FULL/BDR        00:00:38    30.1.1.2        FastEthernet0/0


R1#show ip ospf sham-links
Sham Link OSPF_SL0 to address 111.6.6.6 is up
Area 0 source address 111.5.5.5
  Run as demand circuit
  DoNotAge LSA allowed. Cost of using 1 State POINT_TO_POINT,
  Timer intervals configured, Hello 10, Dead 40, Wait 40,
    Hello due in 00:00:09
    Adjacency State FULL (Hello suppressed)
    Index 2/2, retransmission queue length 0, number of retransmission 0
    First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
    Last retransmission scan length is 0, maximum is 0
    Last retransmission scan time is 0 msec, maximum is 0 msec



R3#show ip ospf sham-links
Sham Link OSPF_SL0 to address 111.5.5.5 is up
Area 0 source address 111.6.6.6
  Run as demand circuit
  DoNotAge LSA allowed. Cost of using 1 State POINT_TO_POINT,
  Timer intervals configured, Hello 10, Dead 40, Wait 40,
    Hello due in 00:00:05
    Adjacency State FULL (Hello suppressed)
    Index 2/2, retransmission queue length 0, number of retransmission 0
    First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
    Last retransmission scan length is 0, maximum is 0
    Last retransmission scan time is 0 msec, maximum is 0 msec










Internetworks

Author & Editor

I am CCIE Technical Instructor/Network consultant. i am having experience of ranging from operating and maintaining PCs and peripherals to network control programs for multi-faceted data communication networks in LAN,MAN, and WAN environments.

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