DMVPN Phase 3 with OSPF

Posted on by zed

Diagram

Hub (R1)

HUB#
interface Ethernet0/0
ip address 10.0.1.2 255.255.255.0
!
ip route 0.0.0.0 0.0.0.0 10.0.1.1
!
interface Tunnel0
ip address 100.0.0.1 255.255.255.0
no ip redirects
ip mtu 1400
ip nhrp map multicast dynamic
ip nhrp network-id 1234
ip nhrp holdtime 360
ip nhrp redirect
ip tcp adjust-mss 1360
ip ospf network point-to-multipoint
ip ospf 1 area 0
tunnel source Ethernet0/0
tunnel mode gre multipoint

Spoke (R2, R3)

SPOKE1#
 interface Ethernet0/0
 ip address 10.0.2.2 255.255.255.0
 !
 ip route 0.0.0.0 0.0.0.0 10.0.2.1
 !
 interface Tunnel0
 ip address 100.0.0.2 255.255.255.0
 no ip redirects
 ip mtu 1400
 ip nhrp map 100.0.0.1 10.0.1.2
 ip nhrp map multicast 10.0.1.2
 ip nhrp network-id 1234
 ip nhrp holdtime 360
 ip nhrp nhs 100.0.0.1
 ip nhrp shortcut
 ip tcp adjust-mss 1360
 ip ospf network point-to-multipoint
 ip ospf 1 area 0
 tunnel source Ethernet0/0
 tunnel mode gre multipoint

SPOKE2#
 interface Ethernet0/0
 ip address 10.0.3.2 255.255.255.0
 !
 ip route 0.0.0.0 0.0.0.0 10.0.3.1

!
 interface Tunnel0
 ip address 100.0.0.3 255.255.255.0
 no ip redirects
 ip mtu 1400
 ip nhrp map 100.0.0.1 10.0.1.2
 ip nhrp map multicast 10.0.1.2
 ip nhrp network-id 1234
 ip nhrp holdtime 360
 ip nhrp nhs 100.0.0.1
 ip nhrp shortcut
 ip tcp adjust-mss 1360
 ip ospf network point-to-multipoint
 ip ospf 1 area 0
 tunnel source Ethernet0/0
 tunnel mode gre multipoint

Troubleshooting

HUB#sh dmvpn
Legend: Attrb --> S - Static, D - Dynamic, I - Incomplete
 N - NATed, L - Local, X - No Socket
 # Ent --> Number of NHRP entries with same NBMA peer
 NHS Status: E --> Expecting Replies, R --> Responding, W --> Waiting
 UpDn Time --> Up or Down Time for a Tunnel
==========================================================================

Interface: Tunnel0, IPv4 NHRP Details
Type:Hub, NHRP Peers:2,

# Ent Peer NBMA Addr Peer Tunnel Add State UpDn Tm Attrb
 ----- --------------- --------------- ----- -------- -----
 1 10.0.2.2 100.0.0.2 UP 01:15:52 D
 1 10.0.3.2 100.0.0.3 UP 01:15:09 D

Before flow between spokes:

SPOKE1#sh dmvpn
Legend: Attrb --> S - Static, D - Dynamic, I - Incomplete
 N - NATed, L - Local, X - No Socket
 # Ent --> Number of NHRP entries with same NBMA peer
 NHS Status: E --> Expecting Replies, R --> Responding, W --> Waiting
 UpDn Time --> Up or Down Time for a Tunnel
==========================================================================

Interface: Tunnel0, IPv4 NHRP Details
Type:Spoke, NHRP Peers:1,

# Ent Peer NBMA Addr Peer Tunnel Add State UpDn Tm Attrb
 ----- --------------- --------------- ----- -------- -----
 1 10.0.1.2 100.0.0.1 UP 01:16:18 S
 

 

SPOKE1#ping 100.0.0.3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 100.0.0.3, timeout is 2 seconds:
!!!!!

After a dynamic tunnel to the other spoke is dynamically enabled

Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms
SPOKE1#sh dmvpn
Legend: Attrb --> S - Static, D - Dynamic, I - Incomplete
N - NATed, L - Local, X - No Socket
# Ent --> Number of NHRP entries with same NBMA peer
NHS Status: E --> Expecting Replies, R --> Responding, W --> Waiting
UpDn Time --> Up or Down Time for a Tunnel
==========================================================================
Interface: Tunnel0, IPv4 NHRP Details
Type:Spoke, NHRP Peers:2,

# Ent Peer NBMA Addr Peer Tunnel Add State UpDn Tm Attrb
----- --------------- --------------- ----- -------- -----
1 10.0.1.2 100.0.0.1 UP 01:16:31 S
1 10.0.3.2 100.0.0.3 UP 00:00:01 D