I am trying to replace an old box with Rpi to simply provide a VPN connection to some remote point from my LAN

All the parts seem to work. From the Rpi I can ping etc local and remote devices and vice versa.

However I can't get a connection between devices on my LAN and the remote LAN.

The firewall is off. The Rpi just has a single Ethernet connector and has two ethernet interfaces - one the ethernet interface and the tunnel interface.

Routes define which interface to use to access the local and remote LAN addresses.

It is as though the Rpi/Stretch doesn't know how route between the two interfaces.

There is no special configuration that I know of in the old Redhat box I am replacing or the other end of the VPN on a Busybox based switch, they just have disabled firewalls and appropriate static routes defined.

Any advice welcome Thankyou

  • so, the PI is a site-to-site VPN endpoint? Which VPN "system" are you using on the raspberry pi? Oct 3, 2018 at 0:02

1 Answer 1


If everything works as expected, except the packet forwarding, then you should verify that packet forwarding is enabled.

You can see the current state with

sysctl net.ipv4.ip_forward

You can enable packet forwarding with

sysctl net.ipv4.ip_forward=1

You can make the setting permanent by placing it in a file in one of the directories mentioned in man sysctl.

  • If that answers your question, you could accept the answer.
    – RalfFriedl
    Oct 3, 2018 at 9:13

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.