How to stop router automatically redirecting...

I've got a BT Voyager 205 router, although I've seen this on other routers...

What happens is when I enter the WAN IP address of my router in to my web browser, it get a 301 redirect back to 192.168.0.1 (the LAN IP of the router) so I get the login page for the router.

The same thing happens if I try anything with the WAP IP address, I get a response as if I was putting the LAN IP address in. e.g. if I scan it with nmap, it returns the open ports for ftp, telnet and http, where as if I scan my computer with SheidsUp! on grc.com, it shows these ports as being closed.

Does anyone know how I can get my router to send requests for its WAN IP out to the Internet so that it gives me the effect of connecting to my router from the Internet?

 

Private IP Addresses cannot be used on the internet.

http://en.wikipedia.org/wiki/Private_IP_address

 

I'm not trying to use my LAN IP address on the Internet, I'm just trying to stop my router from redirecting requests to its WAN IP (from my PC on the LAN) instantly back to it's LAN interface.

Let me try and explain, I'm developing a port knocking program - so I need to send connection requests to the WAN IP of my router (as if it was coming from the Internet), I have my PC set up in the DMZ of my router so that any Internet connection attempts get forwarded to my PC on the LAN - then I monitor the connection attempts there.

This was working fine with my old router that's just broken, but my new one seems to not let me do this - it never sends the packets out in to the Internet (or whatever it is they do) so I get no connection attempts being forwarded to my computer in the DMZ.

 

I don't think you can easily do what you are trying to do. That is send packets out to the internet, for them to return back to the address you sent them from. The ISP's router that is attached to you're router over the ADSL link will receive a packet with the source address the same as the destination address. In normal operation the only time this can occur is if there is a loop. To supress possible loops, the ISP's router will ignore the packet, and it will be droppped.

The only way to reliably test that ports are properly closed is to connect a device to the outside of the firewall/router and try accessing the ports. Obviously with an ADSL router that isn't so simple. Using services such as Shields up is one answer.

The other thing you could try is use a good old analogue modem to connect to the internet and then test your ADSL connection from that modem dial-up connection.

Personally, I'd rely on Shields up, or visit a friends house and use their internet connection to test yours.

 

OK, yeah that's what I've been doing, getting a friend to run my client program to connect to my router. Thing is, that's not much good when you're trying to develop the application and need to test it all the time.

Thanks for the input though, I think I'll try and get my old router going/replace it in the long term.

 

That's a fine idea! Though I'd use an ISP other than AOL. AOL tend to do funny things with dial-up. Another option is to use a pay as you go ISP. They only charge a penny a minute in the UK.

 

Yeah I am kind of averse to AOL... and I really need a longer term solution than a month or whatever a free package offers.

Pay as you go isn't really an option as I'd be tying up the house phone line and paying for it - whereas before it was free - also I'd have to do it off-peak which would mean after 6 (I think).

If I find a router-based fix / something else I'll post it here for other people to see...

Thanks to everyone for putting your bit in,

Phil

 

It might be worth going backto the beginning on this:

Phil, what are you trying to do?

With a standard ADSL router, access to your PC from the internet usually involves port forwarding at the router (in combination with NAT).

So say you have a web service on port 80 of your PC 192.168.0.2. The router's external IP address is 123.123.123.123. Port forwarding for port 80 is set on the router to forward to 192.168.0.2

So if you send a request from the internet to 123.123.123.123:80 the router will forward the packets to 192.168.0.2:80

That gives you two options.

1. You can test the behaviour of your port 80 service (and the application that sits on top of it) from a second PC on the network (sending packets directly to 192.168.0.2:80)
2. You can test that the port forwarding is working correctly by accessing the connection from the internet.

The second option is pretty basic. It will work or it won't. Once the port forwarding is set correctly it is usually pretty much a set and forget. That is unless you are doing something fairly clever/stupid with your sessions.

So why not just use a second PC inside your network to test you application?

The only possible problem could be access by name, but you can use HOST files to simulate external access using names resolved by DNS.

 

Yeah, I could just put in the IP directly on my LAN from another PC, but I wanted to test it as if I were somewhere else, i.e. by sending packets to my router from the Net. I suppose that now I know that the application does work from the Internet I can just send them across my LAN and test/develop it that way.

I just wondered if there was a way to configure my current router so that it routed packets destined to it's WAN IP from the LAN so that it seemed they were coming from the internet, that's the way my belkin router seemed to do it.

Thanks for the input

Phil

 

All NAT does is substitute the internal host's IP address and port number for it's own in the IP header and pass the packets on.

Glad to be of some help

Reggie