Hello,

I already have a VPNServer setup at home, I will be abroad, what I'm looking for is the following solution:

1) Plug ethernet cable from router in router mode (not modem mode) into my MikroTik device and it allows internet
2) then connect to my VPNServer at home, using the OpenVPN Config File
3) as a backup, have the MikroTik work with a 4G dongle, incase local internet goes down, and that still works with the vpn connection.

Which products do this from the range please, if any?

Thank you

Any device with USB port and sufficient features as you need (wireless, performance).
E.g. for wired only use RB750Gr3, for Wireless as well RB962UiGS-5HacT2HnT

Thank you! do you know if there is a compatible suport listed of dongles? for example i want to know if the Huawei E5573 would work for this, connected by USB.

It's very likely Huawei modem will work without any problems, they all use similar interface and are pretty much compatible.
Note that some Huawei modems in HI-Link mode will appear as a USB network card in Mikrotik and you have to use modem web interface to configure it. It will auto-connect to LTE when there's traffic on that interface (or how you configure it).
Another option is Modem mode, where it appears under LTE interface and you can configure more options in Mikrotik, there is no modem web interface and it's same as if you had Mini-PCIe LTE card in a router.
Some modems can be converted from Hi-Link to Modem mode by loading older firmware, but some can't be changed or are locked by service provider.

I only have experience with the Huawei E3372 and with older sticks that present themselves as a USB serial port. These work fine.
The E5573 is not a stick, it is a complete router. You can use that when you have a WiFi MikroTik and you configure it as a client for the E5573.
(you can still use the same MikroTik as an access point, it can operate as client and access point at the same time, when you know the trick)

I only have experience with the Huawei E3372 and with older sticks that present themselves as a USB serial port. These work fine.
The E5573 is not a stick, it is a complete router. You can use that when you have a WiFi MikroTik and you configure it as a client for the E5573.
(you can still use the same MikroTik as an access point, it can operate as client and access point at the same time, when you know the trick)

Thank you, so you think I can use, for example, this MikroTik https://www.amazon.co.uk/MikroTik-RB750 ... B01MSUMVUB
combined with an unlocked E3372 https://www.amazon.co.uk/Huawei-Unlocke ... ers&sr=1-2
and be able to connect with Open VPN Client to my VPN Server using those 2 devices in combination, or a router plugged in to it locally?

Yes, that will work. But I would recommend to get a model with WiFi because then you can also use it on a public WiFi when required.

Yes, that will work. But I would recommend to get a model with WiFi because then you can also use it on a public WiFi when required.

Thank you, I'll stick with the dongle one for now as its about half the price, what I REALLY need is a simple step by step guide how to do the 3 steps i mentioned in the original email, or support from someone I can call to talk me through it so i don't spend 20 hours solving something an expert could solve in 30 mins, how could I do this with MikroTek do you think?

I mean get a MikroTik router with WiFi plus the dongle.
You can (later) configure the WiFi to be a client on someone's WiFi and then connect the VPN over that.
I presume you already know how to configure the router as you have one for your home base where OpenVPN is configured.
When not, and you use another router and a standard OpenVPN server, you need to re-think from square 1 as:
- MikroTik routers are not click-and-play for such use, you need to understand what you are doing
- The OpenVPN on MikroTik is limited and will usually not work with a server configured with general settings, instead of specially tuned for use with MikroTik.

yes, the E3372 works well. I bough one that had the hi-link firmware (appears as network interface, with router giving IP over DHCP and web interface). But then found how-to reflash it to modem (appears as modem/serial port) so it can be used natively by ROS. So if you can get E3372, that one will work for sure.