How to configure Dynamic Multipoint VPN (DMVPN)

DMVPN stands for Dynamic Multipoint Virtual Private Network provides a secure, scalable network b y using IPsec encryption, generic routing encapsulation (GRE) and Next Hop Resolution Protocol (NHRP).

How DMVPN works

DMVPN building the IPsec and GRE connection is an easy and scalable solution.

Hub router has a permanent tunnel to all spokes routers but not between spokes to spokes.

A spoke can send their packet to others spokes using the NHRP server.

Basic steps for DMVPN Configuration:

1. First define the ISAKMP Policy.
2. Authentication
3. Hash
4. Encryption
5. Group
6. Establish IPsec transform set.
7. Esp-des
8. Esp-md5-hmac
9. Esp-aes
10. Asp-sha-hmac
11. Configure tunnel group
12. Group name
13. Group policies
14. Configure NHRP server
15. Configure ipsec profile
16. Router Protocols

 

First defined the IKE polices on hub router

crypto isakmp policy 10

hash md5

authentication pre-share

group 2

encryption des

crypto isakmp key phonenet address 0.0.0.0 0.0.0.0

crypto ipsec transform-set ts1 esp-des esp-md5-hmac

crypto ipsec profile dvpn

set transform-set ts1

interface Loopback0

ip address 192.168.1.1 255.255.255.0

interface Tunnel0

ip address 172.16.0.1 255.255.0.0

ip mtu 1416

ip nhrp authentication corvit

ip nhrp map multicast dynamic

ip nhrp network-id 99

tunnel source Ethernet0/0

tunnel mode gre multipoint

tunnel key 12345

tunnel protection ipsec profile dvpn

router eigrp 1

network 172.16.0.0

network 192.168.1.0

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Configuring the Spoke for DMVPN

 

crypto isakmp policy 1

hash md5

authentication pre-share

group 2

encryption des

crypto isakmp key phonenet address 0.0.0.0 0.0.0.0

crypto ipsec transform-set ts1 esp-des esp-md5-hmac

crypto ipsec profile dvpn

set transform-set ts1

interface Loopback0

ip address 192.168.2.2 255.0.0.0

interface Tunnel0

ip address 172.16.0.2 255.255.0.0

ip mtu 1416

ip nhrp authentication corvit

ip nhrp map 172.16.0.1 1.1.1.1

ip nhrp map multicast 1.1.1.1

ip nhrp network-id 99

ip nhrp nhs 172.16.0.1

tunnel source Ethernet0/0

tunnel mode gre multipoint

tunnel key 12345

tunnel protection ipsec profile dvpn

router eigrp 1

network 172.16.0.0

network 192.168.2.0

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