OpenVPN – Fix Local Domain DNS Resolution on pfSense

domain-name-systemnetworkingopenvpnpfsense

I am currently trying to setup an OpenVPN server with the intention of linking several servers together in order to run the backup jobs over the VPN.

For this example, this is what I have:

  • A pfSense server running OpenVPN (pfsense.vpn)
  • Two clients: client1.vpn and client2.vpn
  • OpenVPN / pfSense configured with the following settings:
    • TUN mode
    • Tunnel network: 10.0.8.0/24
    • Local network: 10.0.255.0/24
    • DNS forwarder enabled
    • Inter-client communication enabled
    • DNS-rebind check disabled
    • OpenVPN pushes the default domain 'vpn' to clients
    • OpenVPN pushes the default DNS server 10.0.8.1 to clients

The problem:

Clients can cannot without any problems. They can also reach each other by pinging the IP-addresses directly. When pinging pfsense, it will automatically resolve though the default search domain, however when pinging any hostname of a connecting client, this will not work.

The routing table for clients seem to be incorrect as well. Example from client1 (10.0.8.10):

10.0.8/24          10.0.8.9           UGSc            1        0    tun0
10.0.8.9           10.0.8.10          UH              3        0    tun0
10.0.255/24        10.0.8.9           UGSc            0        0    tun0

10.0.8.9 points to nothing, so I have no clue where this is coming from.

Why is my local domain resolution not working for VPN-connected clients?

Best Answer

VPN-connected clients don't register their hostnames. Would have to statically assign them via client overrides and manually add to DNS forwarder for them to resolve.

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