VNC and RDP port frward

RouterOS General
1

Hello,

My network has the following layout:

External host(Radius server(192.168.10.7)) <==(LTE conn)==> Mikrotik Router(remote location 10.247.131.202) <==>PC(192.168.88.10)

I set up my Mikrotik router with an LTE conn, that works(ppp-out2).

I can ping from my remote PC(192.168.88.10) to my radius server over the LTE conn.
Local firewall and AV are disabled.

My question is the following about port forwarding.
I followed the instructions on this site: http://wiki.mikrotik.com/wiki/Manual:IP/Firewall/NAT#Forward_all_traffic_to_internal_host

I wish to connect via VNC or RDP from my Radius server to the remote PC

The strange problem is with VNC and RDP.

Example: On the radius server I try to connect with VNC viewer to 10.247.131.202:5900.
Next it asks me for my password. After that it opens a VNC window. The thing is that its black. There is nothing showing in that VNC Viewer window. After a few seconds the viewer window closes.
The same thing happens with RDP. It asks me for the password and then nothing.

There is nothing wrong with the PC. I tried multiple of them. On all the VNC conn works.

any suggestions?

Any help would be greatly appreciated.

2

You likely have a problem with the MTU and/or some firewall that drops all ICMP packets.

3

After a few days of debuging and searching on the net, I have discovered that for example I can not send ping requests over the Mikrotik router from the local network to a remote location that are bigger than 155 bytes(attachments).
The local network(192.168.88.0/24) behind the network does not have that that problem. I can ping on the local network with packets the size 1000 or larger.
That is very strange. The firewall rules have a MTU of 1500.
I have upgraded the firmware to the latest version of the Router and the results are the same.