router config to work with VNC

Peter Coulter peter "at" coulter.ndo.co.uk
Fri Mar 26 20:22:00 2004


Tom,

You'd need to say a bit more about the ActionTec modem before I could answer
questions on it. Even the model name would allow a manual to be dragged up
online. But your modem must be slightly different to mine because if I type
my external (dynamic) IP address into IE it doesn't take me to the modem;
the only way I can access the modem via IE is using 192.168.0.1. 

Also, when it comes to mind: Is the modem a DHCP server? The D-link router
will be a DHCP server by default and you cannot have two DHCP servers on the
same subnet or they will likely be issuing clashing IP addresses. So if both
devices are DHCP servers the facility would have to be disabled in one or
other of them. To me it makes more sense to have the router as the DHCP
sever and thus deactivate the facility in the modem (if such a facility
exists there).

It's rarely enough just to quote an IP address; usually at least the sub-net
mask but also the default gateway are necessary to get the whole picture
(although in most small/home LANs the former can be guessed with almost
complete certainty and the latter with a fair degree of certainty!) So when
you say that you have moved the D-link over to the IP address 192.168.0.2 I
assume you mean you've set the router IP address in the LAN-side set-up
pages. I assume also that it is set to automatically acquire Default Gateway
and DNS server information from the ISP; that will be how the D-link directs
traffic that is not bound for its own sub-net out onto the Internet, I don't
think it really cares too much about the fact it is going through the modem,
it just dumps stuff out the default gateway as its only known route to the
outside world.

I must say there are things that get me excited ... but routers ain't one of
'em! :-)
Looking forward to actually getting to the VNC bit!! ;-)

Peter


> -----Original Message-----
> From: Tom Knowlton [mailto:tom "at" buyersfund.com]
> Sent: 26 March 2004 03:54
> To: coulter; vnc-list "at" realvnc.com
> Subject: RE: router config to work with VNC
> 
> 
> UPDATE:
> 
> I moved my DLink router IP over to 192.168.0.2
> 
> Now when I type 192.168.0.2 it takes me to the DLink Router config (as 
> expected)
> 
> When I type in my static IP address (205.208.XXX.XXX) it takes me to 
> my ActionTec broadband modem config....is that right?
> 
> Now, there is still another IP address, isn't there?  The one that my 
> DLink is using to connect to my ActionTec modem.
> That is the part I am not sure about.
> 
> So I need an answer to that part, plus I still need to get VNC 
> working.
> 
> But the good news is that for the FIRST TIME....I can get to the 
> firewall config for both my DLink Router and my ActionTec broadband 
> modem WITHOUT having to disconnect any cables.  I'm so excited.
> 
> -----Original Message-----
> From: coulter [mailto:coulter "at" coulter.ndo.co.uk]
> Sent: Thursday, March 25, 2004 6:36 AM
> To: vnc-list "at" realvnc.com
> Cc: Tom Knowlton
> Subject: RE: router config to work with VNC
> 
> 
> As noted by other posters your diagram is incomplete.
> 
> However what if does tell me is that you have two devices - namely the 
> Actiontec modem and the D-link router - with the same IP address 
> namely 192.168.0.1 (you say it in words in some of the supporting text 
> but it is not shown in the diagrams).
> 
> First you can't have two devices with the same IP address and not 
> expect problems. Plus your Dlink must be getting very confused -- it's
> supposed to be a router, by definition a router routes! 
> Usually between different sub-nets!! :-)
> But as it is seeing the same IP address 192.168.0.1 on each 
> of its port (both WAN-side and LAN-side) it's likely not a 
> happy bunny.
>   
> For me the easiest way to solve this is to put the modem and the 
> router on different sub-nets as follows: leave the  modem on 
> 192.168.0.1 (the 192.168.0.0/255.255.255.0 sub-net) and put the router 
> on a completely different sub-net. So that it is very clear which
> is which make them very different, thus I suggest putting the 
> router on the 10.0.0.0 / 255.255.255.0 (although really 
> anything other than 192.168.0.x will do). The router being 
> the DHCP server then dishes out LAN IP address to this 
> revised sub-net. The very first consequence of this will be 
> that you can access both devices via IE using their now 
> different IP addresses without having to be disconnect the 
> devices every now and again! ;-) 
> 
> Once you get this difficulty between modem and router sorted you may 
> be able to progress with VNC issues. Set up port-forwarding on each 
> device now as appropriate.
>  
> Good luck,
> P
> 
> > --__--__--
> > 
> > Message: 14
> > Subject: RE: router config to work with VNC
> > Date: Wed, 24 Mar 2004 17:13:21 -0700
> > From: "Tom Knowlton" <tom "at" buyersfund.com>
> > To: "Scott C. Best" <sbest "at" best.com>, <vnc-list "at" realvnc.com>
> > 
> > Does this diagram help any?  (until I can get Kaboodle up
> and running)
> > 
> > 
> > http://www.knowltonfamily.com/config_port_forward.gif