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If my question has been dealt with somwhere in the forum, please apologize. I did search, but apparently not with the appropriate keywords.
My problem relates to the following: For monitoring remotely a weatherstation, I purchased a win-star usb to lan converter, which - in the lan - works well. I also run ddns successfully from this very lan to access a synology station or a video-server etc.
The usb-server, however, comes with a software that listens to the lan and then emulates a USB connection on the PC (win-xp) where the weather station software is installed, which works fine in local lan surrounding. Of course I can "port-forward" the usb server to the ddns hostname.
I am stumbling over the question how to, at the remote end, "reverse" the hostname back into a lan IP address, so my now remotely located USB client software would recognise it as a lan address and do its job.
If I had at the originating "front end" usb weatherstation a PC running, that wouldn't be too hard (there seems to be some software), but I need it running without PC.
Is there a "mapping" or "tunnelling" I am missing, a specific piece of software to help me, or can you recommend a USB to ethernet server whose client software allows specifying a dyndns hostname?
Thanks for your help, Chrimu
Answer by chrimu · Mar 13, 2011 at 11:28 PM
The Ubox 2100 not being compatible with Win7, I had to start from scratch when I changed PC. One of the very rare products I found compatible is called myUTN-50, and it works with Win7, as Ubox 2100 did with XP.
A dedicated Dyndns support is however missing, and I didn't find any USB-server that has... So it is about looking up the correct IP wia Dyndns, then keying it in by hand.
Matter solved for now...
Answer by RotBlitz · Mar 06, 2010 at 11:44 PM
"Obviously, the client-software won't find its server"
I hope this was the key sentence to understand your problem. So, in other words, you have two networks, each with a dynamic IP address. One network is your "normal" LAN with computer, connected via router to the internet, etc. Let's call this LAN-1. The other network is your weather station connected via another router to the internet. Let's call this LAN-2.
Now your problem is to get the client software in LAN-1 talk to the weather station in LAN-2. This totally depends on how you have to configure the client software or usb-to-lan server to reach the weather station. When looking at the manual of your USB-to-LAN server, this is most likely not eligible to cover for WAN connectivity, because everything like PCs, weather stations, printers or other USB devices connecting to it all work in a LAN environment only. Your USB-to-LAN device had to be in LAN-2, and it is hard if not impossible to get your software in LAN-1 connect to the USB device in LAN-2.
I can see two options to maybe make it work nevertheless:
1. Set up a VPN connectivity or TCP relay between LAN-1 and LAN-2, so that you extend your LAN through a VPN tunnel between the two locations, looking like one LAN then, so that all components can work together. The problem may be with LAN-2 not being able to support this, as no computer is running there.
2. See if your weather station can be connected to a TCP/IP network (i.e. router) via other means than via USB, or if your router in LAN-2 has a USB socket, which you could use to connect the weather station. This would most likely allow to connect to it from remote/outside, but makes your USB server obsolete for this purpose. The question is if the weather station's client software would be able to deal with this. Is there also an online manual for your weather station available?
Just another comment on:
"The usb-server reaches out from remote LAN into WAN trough the port-forwarding rules of the router - OK so far."
Not ok, as outgoing connections are normally not restricted and not bound to any forwarding rules. It works by itself, unless your router maybe blocks certain outgoing ports, as you configured it intentionally in the router's settings. Forwarding rules (also called NAT rules, port translation, port forwarding, opening ports) is usually only needed for inbound traffic.
Answer by RotBlitz · Mar 06, 2010 at 09:30 PM
I got the impression you don't understand what DNS and Dynamic DNS is about.
"Of course I can "port-forward" the usb server to the ddns hostname."
No, never! You are to forward a port on your router, from outside to inside. The rule would look like:
AnyIPaddress:port ---> internalIPaddress:port
where internalIPaddress is the internal IP address of the device in your LAN you want to connect to. From a logical network topology standpoint it does not matter if this is USB or wireless or wired or IPoAC or what else...
However, by its nature you should use a static internal IP address scheme within the LAN for those devices you need to reach from outside, unless your router supports also forwarding to devices with dynamic internal IP addresses. Your weather station as such is just another device within your LAN, no matter what way it connects into it or can be reached out of it. Although it may be geographically located remote, from a network standpoint it isn't, unless I understand it totally wrong.
Further, DNS (Domain Name System) is the phone book of the internet, giving the numbers for the names. So, if you connect to your network from outside by using the DynDNS hostname, your client gets the (current) WAN IP address from the DNS for your hostname, which it needs to establish the connection. Then DNS is over and gone.
Now your outside client connects to your network, using the WAN IP address obtained via DNS, using a certain port you have explicitly or implicitly specified, and your router forwards this connect request to the internal device's IP address, as set up with the forwarder rule. On this device must be a running application, listening on this port, so that the connection finally can take place. That's it!
And no, you do not need to run a computer in such a LAN (but there is in fact), but you must ensure that a DDNS updater can run to keep the WAN IP address for your DynDNS hostname updated. Most routers have this functionality abord, but also other devices like your whether station may have it.
In order to get everything sorted out, you may want to work through this wiki entry here.
Answer by chrimu · Mar 06, 2010 at 10:58 PM
Guess neither my network-slang, nor my english are quite up to this...
Whilst I think I quite reasonably understand -or at least successfully got to work- ddns and port forwarding for "standard cases", i.e. those where the device to be connected to runs its own web-server, one forwards ports through a router and its changing WAN address is "followed/backed" by a constant ddns hostname, I am now stalled by a device, that comes as a usb-to-lan server and a corresponding specific client software.
I install the server in a remote location to a router who manages the port-forwarding of this server and updates ddns. At home, I connect a PC through another router, and on this PC I install the client software. This client software looks among the home-lan IP addresses to find the USB-Server and to emulate a usb connection exploitable by the weather-station software.
Obviously, the client-software won't find its server, which from the home-point-of-view carries a (changing) WAN address, as opposed to a LAN address.
Half the way is done (as by the wiki you mention): The usb-server reaches out from remote LAN into WAN trough the port-forwarding rules of the router - OK so far. DDNS allows me to find the ever-changing WAN address of my remote LAN and thus my USB server with its connected weather station - fine.
It is the last step, that isn't clear to me: How can I "specify/emulate/transform" this information again into a home-LAN IP address, so that my client-software expecting something like 192.168.x.x would recognise it.
Maybe this clarifies a bit,
Answer by chrimu · Apr 05, 2010 at 08:33 PM
The best way I found in the end, was to buy a Lantronix Ubox 2100. Its client software allows connecting to IP addresses outside the LAN's firewall, and port-forwarding on the remote end allows the box with the connected weather station to be discovered. So, it won't work over the dyndns hostname, but the dyndns service tells me well which IP my remote station has got. So, with a bit over 100$ spent, that was still 800$ better than the cheapest IP-Weather station I found.
The box is in phase-out, meaning I can't expect future software releases, i.e. porting it to Win7 compatibility. I'm therefore still interested if anyone knows a similar -more recent- product.