krfb to krdc over internet woes

Host system (to be desktop shared) Acer aspire running from gecko-linux live on usb
Client system (to do viewing / interaction) identical acer aspire running leap 15.0 from harddisk normally

Installed krfb with vnc onto host system. ran krfb in kde desktop on host with address 192.168,x.y:5900 (x.y are hide real address) and a password
Ran KRDC on Client and tried to connect to <user>@192.168.x.y:5900 but got no password entry screen just a big blue blank screen.

Host did not get the someone is trying to login to your system message or anything at all. Client used disconnect and exit. Host used her exit and then got the message no operational connection possible – port 5900 unavailable please choose another.

Host system is 3000 miles away and run by a very non-technical person. I finally managed to talk her into sharing her desktop so I can what is going on and it doesn’t work! wow

Can someone tell me what is going on?

Did you open up port 5900 on both machines??

Aside from verifying port 5900 is open on both machines (you can use telnet or some other utility to probe the ports on both machines to verify they’re open and responding),

You may need to SSH into the remote machine, using command lines to verify services are running and firewall configuration.
If you’re unfamiliar how to do this and can’t find a useful guide on the Internet, post your questions here and I’m sure people will offer helpful suggestions.

TSU

During boot on my machine (client) I get message starting OpenSUSEfirewall2 phase 2 … then a started with the usual OK. In Yast under firewall it said no firewalld installed - install now? So near as I can tell I should be using opensusefirewall2 but leap 15.0 wants firewalld which I did download and install but it won’t run because it conflicts with something. Likely the former firewall.

The host is running on Gecko-Linux on USB because we are having a problem with her harddisk and need to recover her info from the drive just in case trying to repair the drive causes more trouble. I know that gecko-linux is a minimalistic system based on leap42.3 KDE dt. I don’t know how to tell what firewall if any she has or how to check it.

When LEAP is installed brand new, it installs firewalld.
When you run the YaST firewall module the first time, it should install firewall-config, the graphical tool to manage your firewalld configurations of ipttables (or ebtalbes).

If you upgraded your openSUSE to LEAP 15,
IIRC you system should migrate your system from SuSEFW2 to firewalld, but your system will still have the SUSEFW2 components installed, just disabled. You cannot activate firewalld without also disabling SuSEFW2, they would conflict managing the underlying iptables/ebtables.

Any openSUSE prior to LEAP 15 will still be uisng SuSEFW2.

If you are able to SSH into the remote system, you can inspect things like the SuSEFW2 and firewalld services, to make sure only one (the correct) one is running only. There is not a ncurses (text mode) version of firewall-config to inspect the firewall configuration, but probing open ports from where you are should be sufficient to understand if the firewall is up and blocking ports or not.

TSU