Tunneling - Implement and troubleshoot DMVPN (single-­‐hub) - DMVPN with IPSec using pre-­‐shared key

8 important questions on Tunneling - Implement and troubleshoot DMVPN (single-­‐hub) - DMVPN with IPSec using pre-­‐shared key

What are the main components of DMVPN?

-mGRE
-NHRP
-Dynamic disovery of ipsec tunnel endpoints

What is the command to configure mGRE?

(config-if)# tunnel mode gre multipoint

A multipoint network

What is the command to automatically add routers to the multicast NHRP mappings?

(conf-if)#ip nhrp map multicast dynamic

Enables multicast over the dmvpn network. Multicast is necassary for routing protocols.

CBT 26 - NHRP in the DMVPN - EIGRP  5:55
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What does the command (config-if) ip nhrp map multicast ip_nhrp-server(real-interface)?

Let the NHRP hub handle the multicast traffic

CBT 26 - NHRP in the DMVPN - EIGRP  9:55

What is the command to configure a mapping for client to find the NHS server?

(config-if)#ip nhrp map tunnel destination real_interface/loopback destination

What is the routing eigrp command to do spoke-2-spoke in case of spoke-2-hub-2-spoke?

(config-if)#no ip next-hop-self eigrp X (tunnel-interface)

CBT 26 - NHRP in the DMVPN - EIGRP 18:00

What is the command to check if dmvpn is static/dynamic?

Spoke1#show 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
----- --------------- --------------- ----- -------- -----
1 172.16.10.1 10.1.1.254 UP 00:00:39 S
2 172.16.10.2 10.1.1.254 UP 00:00:33 D S static
D dynamic

What is the OSPF configuration for DMVPN?

Hub
(config)#int tunnel 0
(config-if)ip ospf type broadcast

Spoke
(config)#int tunnel 0
(config-if)ip ospf type broadcast
(config-if)#ip ospf priority 0 (Spoke must be DR)

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