Finding and connecting to IP address

[Stojakapimp]

So I have a project where I have this little robot which has an 802.11b wireless connection implemented onto it. My goal is to be able to place this robot anywhere and connect to the robot after it connects to a network. So here's my question. If the network gives the robot an internal IP address, is there any way for me to find out that IP address, and if so, can I even connect to the robot since it's an internal address?

The robot has a chip on it which stores it's own website (just some html files), so I need to access those files over the internet while I'm connected to a different network than the robot. Anybody have any ideas on how I might be able to do this?

 

[nweaver]

if you cannot access the routers/firewalls then you probably can't. You would have to forward a port from the outside to port 80 ot the internal IP address. You could get it to "dial home" and send an http form submit to your server that would log the public IP it is reporting. You also might be able to use netcat and leave your machine "listening" for it to dial home in order to issue commands. then the traffic wouldn't need forwarded through routers you can't configure.

 

[Stojakapimp]

Originally posted by: nweaver
if you cannot access the routers/firewalls then you probably can't. You would have to forward a port from the outside to port 80 ot the internal IP address. You could get it to "dial home" and send an http form submit to your server that would log the public IP it is reporting. You also might be able to use netcat and leave your machine "listening" for it to dial home in order to issue commands. then the traffic wouldn't need forwarded through routers you can't configure.

So then would I have any problem at all if the robot were assigned an external IP address? If that were the case, then my only problem would be finding the IP address, correct? do most networks assign internal IP addresses, or is there a good chance that I might luck out and be able to get an external IP address?

 

[Rapidskies]

You have zero chance of this working unless someone helps set it up for you that works on the network. If you can get to some other device on the network that is setup for remote access already you can go from that device to your robot though. All you need is a way inside the network.

 

[nweaver]

I disagree, you could make this work, but you open up some holes.

You use netcat type tool to open a network listening port
Robot uses script/tool/etc to connect to that dd port, perhaps even giving it shell access.

search for reverse proxy or something like that in relation to netcat. It would be a chore, but it's doable.

finding the IP is easy. Build a routine that connects to your machine in some way (http, ftp, ssh, whatever) and you watch for that traffic. Say it hits apache, and you just tail your logs to watch for it to hit your apache server, and then you have the IP address of whatever the world sees as it's public IP.

 

[Rapidskies]

If you can load applications on the robot that would change things. If it is a static webserver and only accepts http connections you are going to have to open that port which would require changes to the firewall/router or getting to the robot from another device on the network.

 

[Yax]

DDNS?

Once the robot registers its hostname, you should be able to use that.

 

[Stojakapimp]

Originally posted by: Yax
DDNS?

Once the robot registers its hostname, you should be able to use that.

Well I am pretty new to this whole DDNS thing, so you'll have to be patient with me.

So let's say that I have some webspace given to me by my school. I found some free DDNS services yesterday and saw that I should use a redirecting website, so now I have a website like mypage.hn.org, which points to my webspace. And then I can set up a DDNS for that hostname? And if I can get that to work, exactly what will I be doing to the robot? Will I make it connect to that hostname somehow whenever it has some wireless connection? I'm just not really sure what my next step would be.

 

[Yax]

Originally posted by: Stojakapimp

Originally posted by: Yax
DDNS?

Once the robot registers its hostname, you should be able to use that.

Well I am pretty new to this whole DDNS thing, so you'll have to be patient with me.

So let's say that I have some webspace given to me by my school. I found some free DDNS services yesterday and saw that I should use a redirecting website, so now I have a website like mypage.hn.org, which points to my webspace. And then I can set up a DDNS for that hostname? And if I can get that to work, exactly what will I be doing to the robot? Will I make it connect to that hostname somehow whenever it has some wireless connection? I'm just not really sure what my next step would be.

The robot is supposed to register its IP and hostname with the DNS server. Then you can reach it via its hostname, regardless of what its IP address is. Once you can communicate with it, you should be able to get its IP address and any other info you need from it.

 

[Stojakapimp]

Originally posted by: Yax

Originally posted by: Stojakapimp

Originally posted by: Yax
DDNS?

Once the robot registers its hostname, you should be able to use that.

Well I am pretty new to this whole DDNS thing, so you'll have to be patient with me.

So let's say that I have some webspace given to me by my school. I found some free DDNS services yesterday and saw that I should use a redirecting website, so now I have a website like mypage.hn.org, which points to my webspace. And then I can set up a DDNS for that hostname? And if I can get that to work, exactly what will I be doing to the robot? Will I make it connect to that hostname somehow whenever it has some wireless connection? I'm just not really sure what my next step would be.

The robot is supposed to register its IP and hostname with the DNS server. Then you can reach it via its hostname, regardless of what its IP address is. Once you can communicate with it, you should be able to get its IP address and any other info you need from it.

So if I do this DDNS server thing, will I need to make the robot it's own web server? And if so, I will have to install certain applications on it, correct?