Hi.
i am currently evaluating to replace devices from a different vendor by Teltonika devices.
We now use for years GRE over OpenVPN with gretap, to get Layer2 routed over Layer3 vpn.
Its important to get this dynamically started via scripts.
how to set the tunnel via shell, on both sides:
ip link add tunnel type gretap remote __remote_ip__
ip link set tunnel up
brctl addif br-lan tunnel
It works well with generic OpenWRT and also with the modified OpenWRT based firmware on the actual routers.
The Teltonika router also allow TCP connections and pings. But its necessary to also be able to use Profinet DCP protocol to find and set profinet devices remotely, which does not work with the Teltonika devices.
I used wireshark remotely on br-lan to see what happens.
On actual devices, the PN-DCP request gets send and there are responses from profinet devices after that: (One request with 5 responses in this example)
On the teltonika, i can see the request, but there are no responses coming in at the br-lan, so it can’t get forwarded to the GRE tunnel.
Is it because the destination MAC does not match with the Teltonika eth MAC?
It seems a bit like the packages are getting blocked before appearing on br-lan.
Hope anyone could help.
Best Regards, Andreas