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I have the following issue:

I have two sites with fibre cable between, this cable has been damaged and the connection is now lost.

Site A need to have connection with site B in order to operate. So I configured a RUT955 at site B and established a IPsec VPN to site A (Sonicwall is installed on Site A). Site A:  Site B:

But then i ran into another problem, the communication between the sites is Profinet, which doesnt support subnetting. So i need Site A and Site B to be on the same Subnet. Is there anyway to do this?

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Good afternoon.

Thank you for your question.

In this situation, you could use an OpenVPN in tap(bridged) mode. However, this would require you to have the same Ip subnet at both ends. I believe it might be more convenient to change your Site B(RUT955) Subnet to so it would match Site A network subnet.

This way you would create a network bridge between these two locations and would avoid the need for subnetting.

OpenVPN TAP/Bridge mode configuration example:


Please review OpenVPN TAP/ Bridge mode configuration and feel free to ask questions regarding it.

Best Regards,

Anton F.


Thank you for your answer I will look into this solution, tomorrow when I am back at the office and give feedback.

I came across another option with IP sec that might be possible here: 


Do you have a recomendation on what would be the "best" solution?

Unfortunatly the Sonicwall in the other end doesnt support OpenVPN so I didnt get i to work.


Ok, what's VPN type support you Sonicwall.

Thank you.

The sonic wall supports IPsec
IPSec with overlapping subnets won't work as Profinet requires L2 data being passed while IPsec works in L3.

If OpenVPN is not available then L2TPv3 can be used:

Yes, that was our conclusion as well unfortunatly.