RealVNC firewall troubles on 3Com officeconnect router

By t_v
Jan 27, 2008
Topic Status:
Not open for further replies.
  1. Nodsu

    Nodsu Newcomer, in training Posts: 9,431

    Oook.. This is a mess. Now, are you really fscking sure that you have only one router? Go to your 3com, grab a hold of every wire going into the box and identify the device at the other end. Then, unplug this 3com thing and see if all the your wireless and wired computers get disconnected.

    It looks like the WAN side of the router is 10.0.0.x and the LAN side is 192.168.10.x. This is OK. But then the wired computer shouldn't be receiving the 10.0.0.x address unless you plugged it in the wrong device.
  2. t_v

    t_v Newcomer, in training Topic Starter Posts: 16

    Thanks a lot for your help :)

    You are correct - it seems to be two devices connected. Please see updated topology.

    Sorry for the confusion - the network is installed at my parents house, 500km away....

    Initially PC1 was connected accordint to "test 1". Now, we also have tried "test 2".

    I would guess that the Thomson device only should alloce 10.x IP to itself and the 3Com router, not PC1?
  3. t_v

    t_v Newcomer, in training Topic Starter Posts: 16

    Great news! It's working ...

    The Thomson router/modem was configured to route VNC directly to one of the network interfaces of the PC. I changed the Thomson router to send these packets to the 3Com router instead. The port forwarding configured at the 3Com router then ensured that the traffic was received at the correct computer / interface. Now I'm able to connect to both computers using VNC, remote desktop and pcAnywhere (also when there is no wired connection).

    Thanks a lot for all your valuable help. It's much appreciated :)
  4. Nodsu

    Nodsu Newcomer, in training Posts: 9,431

    OK, good that you got it sorted out.

    You may want to consider a different set up where the Thomson and 3com are connected via their LAN ports. There would be only one router involved, giving less management overhead and reducing network latency. We have several threads on these forums about connecting two routers.
  5. MarkNC

    MarkNC Newcomer, in training

    Hi, I would like to check my 3com 3C888 router to see if needs the 2.2.0 upgrade. The upgrade Wizard provides a OCRDA address 192.168.200.254 that doesn't work. How can I check my router to see if it needs upgrading, it runs slow. MarkNC
  6. jobeard

    jobeard TS Ambassador Posts: 13,040   +223

    the only issue is what do you have vs. what is available :)

    log into the router config page using your browser
    (run->cmd /k ipconfig /all will show you the GATEWAY address)

    poke about to find the (firmware) version installed.

    Then get another browser window, go to the OEM website and find there support/download page and see what is available for your make+model number.

    If yours doesn't match that which is available, then you need it! download and install it
  7. jobeard

    jobeard TS Ambassador Posts: 13,040   +223

    The Computer-A setup is inconsistent with the router, as you have TWO different
    subnets 10.x wired and 192.x wireless to the same router. Whether wired or wireless,
    a router will normally support ONE subnet, not two.

    Secondly, you can not ping from one end of a VNC connection all the way thru to the other end,
    as the port forwarding is on PORTS and ping is not a port but a Protocol and
    will not follow the forwarding path.

    As you have Server-A and Server-B in one location, get your VNC to connect from one to the other
    as that will be faster to debug. Once that works, getting from the Remote Client to System-A will be better understood.
Topic Status:
Not open for further replies.


Add New Comment

TechSpot Members
Login or sign up for free,
it takes about 30 seconds.
You may also...


Get complete access to the TechSpot community. Join thousands of technology enthusiasts that contribute and share knowledge in our forum. Get a private inbox, upload your own photo gallery and more.