DMVPN - Spoke to Spoke tunnel

[Pratik Prajapati]

Hi,

Once a Spoke to Spoke tunnel is established, what happens if the Hub goes down? Does the Spoke to Spoke tunnel remain active? 

[nkarthikeyan]

If your design is routed via hub, then obvious it will go down. If you have the direct spoke to spoke tunnel establishment along with routing and nhrp updates then it will not affect....

http://www.cisco.com/c/dam/en/us/products/collateral/security/dynamic-multipoint-vpn-dmvpn/prod_presentation0900aecd80313ca0.pdf

Regards

Karthik

[Pratik Prajapati]

For some reason, my spoke to spoke tunnel doesn't stay up when my hub goes down. Not sure what I am missing. Please help!!

Hub:

interface Tunnel0
 ip address 172.16.1.1 255.255.255.0
 no ip redirects
 no ip next-hop-self eigrp 10
 no ip split-horizon eigrp 10
 ip nhrp authentication _GW_
 ip nhrp map multicast dynamic
 ip nhrp network-id 1
 no ip split-horizon
 ip summary-address eigrp 10 10.1.0.0 255.255.0.0
 tunnel source 1.1.1.1
 tunnel mode gre multipoint
 tunnel protection ipsec profile dmvpn
end

spoke 1: 

interface Tunnel0
 ip address 172.16.1.7 255.255.255.0
 no ip redirects
 no ip split-horizon eigrp 10
 ip nhrp authentication _GW_
 ip nhrp map multicast dynamic
 ip nhrp map 172.16.1.1 1.1.1
 ip nhrp map multicast 1.1.1.1
 ip nhrp network-id 1
 ip nhrp nhs 172.16.1.1
 ip summary-address eigrp 10 10.7.0.0 255.255.0.0
 tunnel source GigabitEthernet0/0
 tunnel mode gre multipoint
 tunnel protection ipsec profile dmvpn
end

Spoke 2:

interface Tunnel0
 ip address 172.16.1.6 255.255.255.0
 no ip redirects
 no ip split-horizon eigrp 10
 ip nhrp authentication _GW_
 ip nhrp map multicast dynamic
 ip nhrp map 172.16.1.1 1.1.1.1
 ip nhrp map multicast 1.1.1.1
 ip nhrp network-id 1
 ip nhrp nhs 172.16.1.1
 ip summary-address eigrp 10 10.6.0.0 255.255.0.0
 tunnel source GigabitEthernet0/0
 tunnel mode gre multipoint
 tunnel protection ipsec profile dmvpn
end