Unable to use web-interface to configure D-Link ADSL Modem

[root.veg]

Strange one, this: I just took delivery of a D-Link ADSL modem. It's an ethernet-connection design (one RJ-11 socket for the ADSL line, one RJ-45 for an ethernet connection).

Anyway, I've got two ethernet NICs in my gateway box - eventually eth0 will connect to my local, private IP network, and eth1 will connect to the ADSL modem. I haven't actually bought an ADSL subscription yet, but I had a go at configuring the modem using the web-based interface, just to see if the thing was working OK and what options I have.

I followed the install instructions exactly, which were:

1) Make sure the computer isn't networked to anything else. So I brought down all my other network interfaces (in my case, i ran ifdown eth0 and ifdown eth2). Confirmed this by running ifconfig, and only the loopback interface showed up. I also stopped Shorewall, which was doing my firewalling and routing. Checked this by running iptables -L .

2) Connect the computer's NIC directly to the ADSL modem using a straight-through cat5 cable, and turn the modem on. I used the NIC named eth1 on my computer, by the way. Modem shows the "active connection" light when I plug the cable in.

3) Configure the computer's ethernet interface to use the DHCP server built in to the modem. As I'm using Debian, I did this by adding the line "iface eth1 inet dhcp" in /etc/network/interfaces . Then I ran ifup eth1. After that, ifconfig showed that my eth1 had an IP address of 192.168.0.2 , plus the gateway and broadcast addresses had been set, indicating that the modem's DHCP server had done its job.

4) Run a web-browser (I used Mozilla) and point it at http://192.168.0.1 , which should bring up the web-page where you can configure the modem. So I did. But it point-blank refuses to work :( Mozilla immediately says "Connection was refused when contacting 192.168.0.1").

And there's my problem: I've done everything as the instructions told me, but I can't see the web page I'm supposed to. Any ideas? Or should I just return it to the people I bought it from and say "it doesn't work"?

PS Stuff I've tried already:

1) ping 192.168.0.1 - works perfectly, however, *still* works perfectly even when I physically disconnect the cable from the modem. Weird, huh?
2) ping random IP addresses - works as expected, ie no response. Also noticed while doing this that the message "eth1: entering full-duplex mode according to auto-negotiated partner ability..." keeps appearing on the console every minute or so. Is this just the DHCP server constantly renewing the lease?
3) lynx instead of Mozilla - doesn't work
4) connect modem to NIC using cross-over cable - doesn't work
5) connecting both the modem and the NIC to my hub, using straight-through cables - the modem doesn't indicate an active connection.
6) tried the URL http://192.168.0.1/index.html
7) made sure Mozilla isn't set to use a proxy server.

[fredg]

Originally posted by root.veg

PS Stuff I've tried already:

1) ping 192.168.0.1 - works perfectly, however, *still* works perfectly even when I physically disconnect the cable from the modem. Weird, huh?


This should be attracting your attention. It indicates that there is ANOTHER interface or host configured to use the 192.168.0.0 network and 192.168.0.1 address.

If you have two (or more) interfaces in a machine configured to be in the same or overlapping networks, neither interface will work properly. So rule this out first with ifconfig to see that this is not the case.

[camelrider]

Does your gateway machine run a DHCP server? It sounds like the IP number may have been assigned to the modem by the local machine which reserved 192.168.0.1 for itself.
When you are connecting to an ADSL service with PPPOE the interface on that NIC (eth1 in your case) will be ppp0 and will get its IP number from the DHCP server at your ISP.
Unless your modem is also a router I doubt it is capable of assigning IP's on it own.
(edit) Since your modem seems to have been assigned 192.168.0.2 you might try pointing your browser to that IP.(edit)

[root.veg]

Thanks for your responses, guys... I will check out what you suggested and post back with more info...

[root.veg]

Well it's sorted for the moment.

I wasn't running a DHCP server on the computer. "why not?" you ask... well because I only have a maximum of 3 computers on my network, I used static IPs and an /etc/hosts file on each computer. So although I had switched off my other network interfaces, and ifconfig confirmed that, I still had an entry for 192.168.0.1 in my /etc/hosts file. I guess that explains the confusion.

I can now use the built-in DHCP server in the modem OK and view the configuration web-pages OK. Of course, it'll be a while before I can do anything useful, as I haven't bought my connection yet... but thanks for the pointers, guys :)

[camelrider]

Glad you got it sorted, even if we didn't hit the nail right on the head!
:)