IKEV2 and DHCP

djhurt1

We're still looking at the hub and spoke setup. Clients behind the spoke firewalls are to lease an address via DHCP back to the main server behind the hub firewall. Originally I thought I could just do an Ip helper/relay agent. I ran across documentation that mentions something called DHCP over VPN which I've never heard of. I also found what appears to be some older sonicwall documentation that states "DHCP over VPN" will not work with IKE.

1. What are my options for DHCP across the VPN back to the hub?
2. How does "DHCP over VPN" really work?

Saravanan

Hi @DJHURT1,

Thank you for visiting SonicWall Community.

DHCP over VPN works with "Site to Site" policy type.

The below KB article should suit your requirement for DHCP across the VPN back to the hub.

https://www.sonicwall.com/support/knowledge-base/vpn-using-ip-helper-to-obtain-dhcp-over-a-policy-based-site-to-site-vpn-tunnel/170503864888105/

The purpose of the DHCP over VPN is, it enables the clients of the SonicWall appliance to obtain IP addresses from a SonicWall DHCP server at the other end of the VPN tunnel or a local DHCP server.

Hope this helps.

djhurt1

@Saravanan

I'm confused by your last statement. "The purpose of the DHCP over VPN is, it enables the clients of the SonicWall appliance to obtain IP addresses from a SonicWall DHCP server at the other end of the VPN tunnel or a local DHCP server.". If I have a local DHCP server, why would I even use DHCP over VPN?

Saravanan

Hi @djhurt1,

DHCP over VPN enables clients of the SonicWALL appliance to obtain IP addresses from a DHCP server at the other end of the VPN tunnel or a local DHCP server. This is for a specific requirement where Corporate and Remote Offices on different locations share the same subnet while they are connected over Site to Site IPsec VPN.

Hope this clarifies.

djhurt1

"DHCP over VPN enables clients of the SonicWALL appliance to obtain IP addresses from a DHCP server at the other end of the VPN tunnel or a local DHCP server."

Why would you use "DHCP over VPN" if there is a local DHCP server?

Saravanan

Hi @DJHURT1,

As mentioned in my last comment, "This is for a specific requirement where Corporate and Remote Offices on different locations share the same subnet while they are connected over Site to Site IPsec VPN". The DHCP over VPN can be used with or without local DHCP server.