How to configure EIGRP and OSPF over DMVPN Phase 1 & 2?

The IP NHRP map multicast dynamic enables the forwarding of multicast traffic across the tunnel to dynamic spokes. This is usually required by the rou


As we already discuss Phase 1 is Not used nowadays, In phase 1 we use NHRP so that spokes can register themselves with the hub (NHRP needed for spokes to register with hub). The hub is the only router that is using a multipoint GRE (mGRE) interface, all spokes will be using regular point-to-point GRE tunnel interfaces. No spokes hub and spokes topology were dynamic IP addresses on the spokes may be used. All your traffic goes through the hub. This means that there will be no direct spoke-to-spoke communication; all traffic has to go through the hub.

Before we start our configuration of EIGRP and OSPF over DMVPN, we need to understand few things about EIGRP and OSPF.

The IP NHRP map multicast dynamic enables the forwarding of multicast traffic across the tunnel to dynamic spokes. This is usually required by the routing protocol as OSPF and EIGRP. In most cases, DMVPN is accompanied by a routing protocol to send and receive dynamic updates about the private networks. The IP NHRP map multicast dynamic command is not required if we are using static NHRP mappings.

EIGRP routers will not be advertising back on the same interface because of the split horizon rules the split-horizon rule prohibits a router from advertising a route through an interface that the router itself uses to reach the destination. To disable the split-horizon behavior, use the { NO IP SPLIT-HORIZON EIGRP AS-number interfaces command. Split horizon behavior is turned on by default. When you change the EIGRP split-horizon setting on an interface, it reset all adjacencies with EIGRP neighbors reachable over that interface. The split horizon should only be disabled on the hub site in a hub and spoke network.

Disabling split-horizon on the spokes radically increases EIGRP memory consumption on the hub router and the amount of traffic generated on the spoke routers.

By default, OSPF handles tunnel interface as a point-to-point interface no matter even if you configure multipoint GRE.  we will get neighbourship goes down messages repeatedly. to over this issue, we need to change the default setting we will see in this OSPF LAB.


Let see the configuration-_

Topology:-




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)#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)#no keepalive

R1(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)#interface serial 4/1

R2(config-if)#ip address 3.3.3.1 255.0.0.0

R2(config-if)#no shutdown


R2(config-if)#interface serial 4/2

R2(config-if)#ip address 4.4.4.1 255.0.0.0

R2(config-if)#no shutdown


R2(config-if)#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)#no keepalive

R2(config-if)#exit


R3(config)#interface serial 4/1
R3(config-if)#ip address 3.3.3.2 255.0.0.0
R3(config-if)#no shutdown

R3(config-if)#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)#no keepalive
R3(config-if)#exit

R4(config)#interface serial 4/2
R4(config-if)#ip address 4.4.4.2 255.0.0.0
R4(config-if)#no shutdown

R4(config-if)#interface fastethernet 0/0
R4(config-if)#ip address 40.1.1.1 255.0.0.0
R4(config-if)#no shutdown
R4(config-if)#no keepalive
R4(config-if)#exit

R1(config)#ip route 0.0.0.0 0.0.0.0 serial 4/0
R1(config)#exit


R2(config)#ip route 1.0.0.0 255.0.0.0 serial 4/0
R2(config)#ip route 10.0.0.0 255.0.0.0 serial 4/0
R2(config)#ip route 30.0.0.0 255.0.0.0 serial 4/1
R2(config)#ip route 3.0.0.0 255.0.0.0 serial 4/1
R2(config)#ip route 4.0.0.0 255.0.0.0 serial 4/2
R2(config)#ip route 40.0.0.0 255.0.0.0 serial 4/2
R2(config)#exit


R3(config)#ip route 0.0.0.0 0.0.0.0 serial 4/1
R3(config)#exit

R4(config-if)#ip route 0.0.0.0 0.0.0.0 serial 4/2
R4(config)#exit

R1(config)#interface tunnel 4321

R1(config-if)#ip address 192.168.1.1 255.255.255.0
R1(config-if)#tunnel source 1.1.1.1
R1(config-if)#tunnel mode gre multipoint
R1(config-if)#ip nhrp network-id
R1(config-if)#ip nhrp network-id 01
R1(config-if)#exit


R3(config)#interface tunnel 4321
R3(config-if)#ip address 192.168.1.3 255.255.255.0
R3(config-if)#tunnel source 3.3.3.2
R3(config-if)#tunnel destination 1.1.1.1
R3(config-if)#ip nhrp network-id 02
R3(config-if)#ip nhrp nhs 192.168.1.1
R3(config-if)#ip nhrp map 192.168.1.1 1.1.1.1
R3(config-if)#exit

*Apr 26 17:31:35.035: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel4321, changed state to up

*Apr 26 17:30:23.119: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel4321, changed state to up


R4(config)#interface tunnel 4321

R4(config-if)#ip address 192.168.1.4 255.255.255.0

R4(config-if)#tunnel source 4.4.4.2

R4(config-if)#tunnel destination 1.1.1.1

R4(config-if)#ip nhrp network-id 03

R4(config-if)#ip nhrp nhs 192.168.1.1

R4(config-if)#ip nhrp map 192.168.1.1 1.1.1.1

R4(config-if)#exit

*Apr 26 17:33:21.431: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel4321, changed state to up

R1#ping 192.168.1.3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/30/64 ms

R1#ping 192.168.1.4
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.4, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/23/32 ms

R3#ping 192.168.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 8/16/24 ms

R3#ping 192.168.1.4
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.4, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/61/64 ms

R4#ping 192.168.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/33/52 ms

R4#ping 192.168.1.3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 20/64/104 ms

R3#traceroute 192.168.1.4
Type escape sequence to abort.
Tracing the route to 192.168.1.4
VRF info: (vrf in name/id, vrf out name/id)
  1 192.168.1.1 24 msec 32 msec 28 msec
  2 192.168.1.4 64 msec 60 msec 72 msec


R4#traceroute 192.168.1.3
Type escape sequence to abort.
Tracing the route to 192.168.1.3
VRF info: (vrf in name/id, vrf out name/id)
  1 192.168.1.1 28 msec 28 msec 48 msec
  2 192.168.1.3 100 msec 60 msec 56 msec


R1(config)#router eigrp 4321
R1(config-router)#no auto-summary
R1(config-router)#network 10.1.1.0
R1(config-router)#network 192.168.1.0
R1(config-router)#exit


*Apr 26 18:09:57.479: %DUAL-5-NBRCHANGE: EIGRP-IPv4 4321: Neighbor 192.168.1.3 (Tunnel4321) is down: retry l   

*Apr 26 18:11:55.831: %DUAL-5-NBRCHANGE: EIGRP-IPv4 4321: Neighbor 192.168.1.4 (Tunnel4321) is down: retry limit exceeded


R1(config)#interface tunnel 4321
R1(config-if)#ip nhrp map multicast dynamic


*Apr 26 18:14:05.555: %DUAL-5-NBRCHANGE: EIGRP-IPv4 4321: Neighbor 192.168.1.3 (Tunnel4321) is up: new adjacency

R1(config)#interface tunnel 4321
R1(config-if)#no ip split-horizon eigrp 4321


*Apr 26 18:15:18.075: %DUAL-5-NBRCHANGE: EIGRP-IPv4 4321: Neighbor 192.168.1.4 (Tunnel4321) is down: split horizon changed
*Apr 26 18:15:18.111: %DUAL-5-NBRCHANGE: EIGRP-IPv4 4321: Neighbor 192.168.1.3 (Tunnel4321) is down: split horizon changed

*Apr 26 18:15:19.799: %DUAL-5-NBRCHANGE: EIGRP-IPv4 4321: Neighbor 192.168.1.3 (Tunnel4321) is up: new adjacency
*Apr 26 18:15:19.899: %DUAL-5-NBRCHANGE: EIGRP-IPv4 4321: Neighbor 192.168.1.4 (Tunnel4321) is up: new adjacency






R3(config)#router eigrp 4321
R3(config-router)#no auto-summary
R3(config-router)#network 192.168.1.0
R3(config-router)#network 30.0.0.0
R3(config-router)#exit


R3(config)#interface tunnel 4321
R3(config-if)#shutdown
R3(config-if)#no shutdown


R4(config)#router eigrp 4321
R4(config-router)#no auto-summary
R4(config-router)#network 192.168.1.0
R4(config-router)#network 40.0.0.0
R4(config-router)#exit

R1#show ip route eigrp
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 0.0.0.0 to network 0.0.0.0

D     30.0.0.0/8 [90/26882560] via 192.168.1.3, 00:01:32, Tunnel4321
D     40.0.0.0/8 [90/26882560] via 192.168.1.4, 00:30:10, Tunnel4321



R3#show ip route eigrp
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 0.0.0.0 to network 0.0.0.0

D     10.0.0.0/8 [90/26882560] via 192.168.1.1, 00:01:39, Tunnel4321
D     40.0.0.0/8 [90/28162560] via 192.168.1.1, 00:01:39, Tunnel4321

R4#show ip route eigrp
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 0.0.0.0 to network 0.0.0.0

D     10.0.0.0/8 [90/26882560] via 192.168.1.1, 00:30:24, Tunnel4321
D     30.0.0.0/8 [90/28162560] via 192.168.1.1, 00:01:45, Tunnel4321

R1#show ip eigrp neighbors
EIGRP-IPv4 Neighbors for AS(4321)
H   Address                 Interface              Hold Uptime   SRTT   RTO  Q  Seq
                                                   (sec)         (ms)       Cnt Num
1   192.168.1.3             Tu4321                   12 00:04:36   40  1470  0  3
0   192.168.1.4             Tu4321                   11 00:32:54   51  1470  0  4

R3#show ip eigrp neighbors
EIGRP-IPv4 Neighbors for AS(4321)
H   Address                 Interface              Hold Uptime   SRTT   RTO  Q  Seq
                                                   (sec)         (ms)       Cnt Num
0   192.168.1.1             Tu4321                   11 00:03:42   30  1470  0  42


R4#show ip eigrp neighbors
EIGRP-IPv4 Neighbors for AS(4321)
H   Address                 Interface              Hold Uptime   SRTT   RTO  Q  Seq
                                                   (sec)         (ms)       Cnt Num
0   192.168.1.1             Tu4321                   11 00:32:25  482  2892  0  42



R4#traceroute 192.168.1.1
Type escape sequence to abort.
Tracing the route to 192.168.1.1
VRF info: (vrf in name/id, vrf out name/id)
  1 192.168.1.1 20 msec 32 msec 44 msec

R4#traceroute 192.168.1.3
Type escape sequence to abort.
Tracing the route to 192.168.1.3
VRF info: (vrf in name/id, vrf out name/id)
  1 192.168.1.1 12 msec 40 msec 32 msec
  2 192.168.1.3 96 msec 52 msec 48 msec

R3#traceroute 192.168.1.1
Type escape sequence to abort.
Tracing the route to 192.168.1.1
VRF info: (vrf in name/id, vrf out name/id)
  1 192.168.1.1 36 msec 16 msec 28 msec

R3#traceroute 192.168.1.4
Type escape sequence to abort.
Tracing the route to 192.168.1.4
VRF info: (vrf in name/id, vrf out name/id)
  1 192.168.1.1 28 msec 36 msec 44 msec
  2 192.168.1.4 56 msec 48 msec 60 msec


___________________________________________________________________________

We are continuing our lab with some small changes. remove EIGRP 4321, renable split-horizon reconfigure DMVPN phase 1 using OSPF 1.








R1(config)#router ospf 4321
R1(config-router)#router-id 10.1.1.1
R1(config-router)#network 10.0.0.0 0.255.255.255 area 0
R1(config-router)#network 192.168.1.0  255.0.0.0 area 0


*Apr 26 19:34:29.111: %OSPF-5-ADJCHG: Process 4321, Nbr 40.1.1.1 on Tunnel4321 from INIT to DOWN, Neighbor Down: Adjacency forced to reset

*Apr 26 19:34:29.367: %OSPF-5-ADJCHG: Process 4321, Nbr 30.1.1.1 on Tunnel4321 from INIT to DOWN, Neighbor Down: Interface down or detached


R3(config)#router ospf 4321
R3(config-router)#router-id 30.1.1.1
R3(config-router)#network 30.0.0.0 0.255.255.255 area 0
R3(config-router)#network 192.168.1.0 0.0.0.255 area 0
R3(config-router)#exit

R4(config)#router ospf 4321
R4(config-router)#router-id 40.1.1.1
R4(config-router)#network 40.1.1.1 0.255.255.255 area 0
R4(config-router)#network 192.168.1.0 0.0.0.255 area 0
R4(config-router)#exit

R1(config)#interface tunnel 4321
R1(config-if)#ip ospf network point-to-multipoint                                                   
R1(config-if)#exit


*Apr 26 19:42:42.059: %OSPF-5-ADJCHG: Process 4321, Nbr 40.1.1.1 on Tunnel4321 from LOADING to FULL, Loading Done

*Apr 26 19:42:45.143: %OSPF-5-ADJCHG: Process 4321, Nbr 30.1.1.1 on Tunnel4321 from LOADING to FULL, Loading Done


R3(config)#interface tunnel 4321
R3(config-if)#ip ospf network point-to-multipoint
R3(config-if)#exit


R4(config)#interface tunnel 4321
R4(config-if)#ip ospf network point-to-multipoint                                                        
R4(config-if)#exit

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 0.0.0.0 to network 0.0.0.0

O     30.0.0.0/8 [110/1001] via 192.168.1.3, 00:08:22, Tunnel4321
O     40.0.0.0/8 [110/1001] via 192.168.1.4, 00:07:53, Tunnel4321
      192.168.1.0/24 is variably subnetted, 4 subnets, 2 masks
O        192.168.1.3/32 [110/1000] via 192.168.1.3, 00:08:22, Tunnel4321
O        192.168.1.4/32 [110/1000] via 192.168.1.4, 00:07:53, Tunnel4321


R1#show ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
40.1.1.1          0   FULL/  -        00:01:36    192.168.1.4     Tunnel4321
30.1.1.1          0   FULL/  -        00:01:40    192.168.1.3     Tunnel4321



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 0.0.0.0 to network 0.0.0.0

O     10.0.0.0/8 [110/1001] via 192.168.1.1, 00:01:51, Tunnel4321
O     40.0.0.0/8 [110/2001] via 192.168.1.1, 00:01:51, Tunnel4321
      192.168.1.0/24 is variably subnetted, 4 subnets, 2 masks
O        192.168.1.1/32 [110/1000] via 192.168.1.1, 00:01:51, Tunnel4321
O        192.168.1.4/32 [110/2000] via 192.168.1.1, 00:01:51, Tunnel4321


R3#show ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
10.1.1.1          0   FULL/  -        00:00:04    192.168.1.1     Tunnel4321

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 0.0.0.0 to network 0.0.0.0

O     10.0.0.0/8 [110/1001] via 192.168.1.1, 00:00:16, Tunnel4321
O     30.0.0.0/8 [110/2001] via 192.168.1.1, 00:00:16, Tunnel4321
      192.168.1.0/24 is variably subnetted, 4 subnets, 2 masks
O        192.168.1.1/32 [110/1000] via 192.168.1.1, 00:00:16, Tunnel4321
O        192.168.1.3/32 [110/2000] via 192.168.1.1, 00:00:16, Tunnel4321

R4#show ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
10.1.1.1          0   FULL/  -        00:01:48    192.168.1.1     Tunnel4321



R4#traceroute 192.168.1.1
Type escape sequence to abort.
Tracing the route to 192.168.1.1
VRF info: (vrf in name/id, vrf out name/id)
  1 192.168.1.1 60 msec 44 msec 16 msec

R4#traceroute 192.168.1.3
Type escape sequence to abort.
Tracing the route to 192.168.1.3
VRF info: (vrf in name/id, vrf out name/id)
  1 192.168.1.1 20 msec 48 msec 28 msec
  2 192.168.1.3 52 msec 32 msec 48 msec


R3#traceroute 192.168.1.1
Type escape sequence to abort.
Tracing the route to 192.168.1.1
VRF info: (vrf in name/id, vrf out name/id)
  1 192.168.1.1 24 msec 40 msec 12 msec

R3#traceroute 192.168.1.4
Type escape sequence to abort.
Tracing the route to 192.168.1.4
VRF info: (vrf in name/id, vrf out name/id)
  1 192.168.1.1 16 msec 36 msec 36 msec
  2 192.168.1.4 56 msec 44 msec 44 msec

R1#traceroute 192.168.1.3
Type escape sequence to abort.
Tracing the route to 192.168.1.3
VRF info: (vrf in name/id, vrf out name/id)
  1 192.168.1.3 64 msec 64 msec 32 msec

R1#traceroute 192.168.1.4
Type escape sequence to abort.
Tracing the route to 192.168.1.4
VRF info: (vrf in name/id, vrf out name/id)
  1 192.168.1.4 44 msec 24 msec 44 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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