VPN from client to office on the same subnet

[paulhuynh81]

Is this possible?

From Home subnet is 192.168.1.0/255.255.255.0–---OfficeWan-Office Subnet is also 192.168.1.0/255.255.255.0

My current Watchguard is able to make this work it hand out 192.168.30.0/255.255.255.0 for the vpn client ip and route all traffic back to the office

I a hoping i can keep the same thign going using pfsense and replace the watchguard.

[phil.davis]

You can using OpenVPN TAP mode to bridge across the link. But IMHO you are better off not to have all the broadcast traffic. Use a different subnet at each end and an OpenVPN TUN site-to-site link between them.

[heper]

or nat the lan subnet over the vpn (messy)

[jimp]

We discovered after some testing today that this is possible and works fine, at least with a Windows client. Other operating systems may react differently.

OpenVPN, when pushed a conflicting route, adds an additional route with a lower metric to send the traffic across the VPN:

Not Connected:

Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0    192.168.xxx.2  192.168.xxx.131      10
    192.168.xxx.0    255.255.255.0  192.168.xxx.131  192.168.xxx.131      10
  192.168.xxx.131  255.255.255.255        127.0.0.1       127.0.0.1       10
  192.168.xxx.255  255.255.255.255  192.168.xxx.131  192.168.xxx.131      10

Connected:

Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0    192.168.xxx.2  192.168.xxx.131      10
    192.168.xxx.0    255.255.255.0  192.168.xxx.131  192.168.xxx.131      10
    192.168.xxx.0    255.255.255.0       10.46.75.5      10.46.75.6       1
  192.168.xxx.131  255.255.255.255        127.0.0.1       127.0.0.1       10
  192.168.xxx.255  255.255.255.255  192.168.xxx.131  192.168.xxx.131      10

What this means is that, while connected, your traffic to 192.168.xxx.0/24 will go across the VPN, but you lose connectivity to your local subnet except for the gateway. In most cases that's a non-issue since it's likely a coffee shop, airport, hotel, etc. If you'd need anything there it may be a DNS server but you can push the client one of those, too.

Once you disconnect from the VPN, local connectivity is restored.

[craigduff]

How many nodes does your home network consist of? normally for home users its one computer and router and maybe a few ipads for the kids. Just change the network range on the router. So much easier!