My laptop OpenVPN client establishes a TAP device. My client config is TUN, though. This devices shows under ifconfig /ALL with the IP 10.8.0.6
and a subnetmask of 255.255.255.252. (!!!)
This subnetmask is obviously a multi client mask setup which gives only 4 IPs from the subnet to each client.
I have troubles pinging LAN clients inside and outside the tunnel on the remote LAN and suspect the multi client mask to be the reason.
How can I change the mask to a standard 255.255.255.0?
More details:
I run a Synology Disk Station NAS in my home (remote) network with the IP beeing 192.168.0.8. The router/standard gateway is an Ubiquity ER-X with 192.168.0.1.
This NAS has an OpenVPN Server. I can connect to this server with my client on the LAN/Wifi at work (gateway 192.168.1.1; IP of my laptop in the wifi is 192.168.5.121; tunnel IP is 10.8.0.6).
The tunnel gives my laptop an IP of 10.8.0.6 and my remote server on the NAS has 10.8.0.5
I disabled my laptop firewall (Windows 10).
I can connect via my laptop browser to https://10.8.0.1:5001 which is the web GUI of the Synology NAS Disk Managment System, a GUI of the operating system.
The weird thing: I can not ping this IP 10.8.0.1 although I am connected via the browser on parallel.
Best Answer
Putting
topology subnet
as one single line into the client configuration file will solve this (only whendev tun
is used).I found this after a discussion with some nice people here.
More details on why multi-client setup was necessary for usage with older versions of windows TAP devices can be found here.