DHCP Relay and AutoVPN

[iores]

Hi,

What path will spoke use to get to DHCP if (1) full tunnel or (2) split tunnel is used? DHCP is at HQ, behind L3 core switch which is connected to the hub.

My guess is that with full tunnel, all traffic will go via AutoVPN tunnel to the hub.

As with split tunnel, if the DHCP needs to be reached through AutoVPN then static route pointing to DHCP should be redistributed in AutoVPN at the hub. Otherwise, it will be routed normally - decapsulated.

Does this sound correct?

[jimmyt234]

I am fairly sure it will error if you try to save a DHCP Relay IP that the MX is not learning a route for via AutoVPN

[iores]

So it needs to be specific route, not default route?

[iores]

I forgot to mention, the hub will be in 1-arm concentrator mode.

[ww]

Yes it works how you described.

"IP address of DHCP server to relay to. The IP address must be in a subnet connected to this Meraki network or to a Meraki network reachable through site-to-site VPN. Relaying through a non-Meraki VPN peer is not supported."

[alemabrahao]

Sorry, but wouldn't it be much simpler to configure the DHCP server on each spoke than to have a centralized server for everything?

Have you ever wondered what will happen if the spokes lose communication with this DHCP server?

[iores]

I understand what you are saying but, unfortunatelly, configuring DHCP server on each spoke is not an option.

[alemabrahao]

Good luck 🤞