Does anyone know of a tool which will let me discover the IP address of my ADSL modem in this setup :
LAN <----> switch <----> Linux Server <----> ADSL Modem
My computer is in the LAN, the Linux server is a Debian Box with no monitor or keyboard, and the ADSL modem is a DLink 302G (the kind you get free with an Xtra connection). The Linux server has two network cards in it, one connected to the switch (eth0), and one connected straight to the modem(eth1).
The ADSL modem has been configured into half-bridge mode as discussed on the wlug wiki page for it (http://wlug.org.nz/DSL-302G), which means the IP address that appears on the Linux box is the external IP address of the modem, or at least the last one that was used.
Now the problem is, I want to update some configuration on the modem, but I cannot remember what the IP address for it is. All I remember was that I changed it from its default.
Does anyone know of a command, presumably that I would run from the linux box that I can use to find out the IP address of the modem that I browse to, to configure it?
-- Cameron
* Camster342 camster342@gmail.com [2005-09-26 07:15]:
Does anyone know of a command, presumably that I would run from the linux box that I can use to find out the IP address of the modem that I browse to, to configure it?
That would be “ifconfig”, no?
Regards,
On 26/09/05, A. Pagaltzis pagaltzis@gmx.de wrote:
- Camster342 camster342@gmail.com [2005-09-26 07:15]:
Does anyone know of a command, presumably that I would run from the linux box that I can use to find out the IP address of the modem that I browse to, to configure it?
That would be "ifconfig", no?
No. ifconfig reports the external IP address of the modem. Basically, the modem is just repeating all IP traffic that comes in from the outside world to it's local segment, which is a straight connection to the linux box. The one big exception to this is the adsl modem also acts as a DHCP server, and updates the linux box's IP address every minute or so with the modems external IP address.
The adsl modem will not accept connections going to its webpage when the packets have the destination of it's external IP, only it's internal IP. It _was_ 10.1.1.1, but I've changed it. I just don't remember what I changed it to...
-- Cameron
On Mon, 2005-09-26 at 02:27 -0400, Camster342 wrote:
On 26/09/05, A. Pagaltzis pagaltzis@gmx.de wrote:
- Camster342 camster342@gmail.com [2005-09-26 07:15]:
Does anyone know of a command, presumably that I would run from the linux box that I can use to find out the IP address of the modem that I browse to, to configure it?
There are a couple of things you can try. Hopefully you can at least remember what network you put the router in. If so, the best course of action is to ping the broadcast address and hope that the router responds. If your network is a /24 the broadcast address will be .255. Google can probably tell you what it is if your network is not a /24.
If you can't remember the network that you configured the router onto then I would suggest that you run tcpdump on the interface connected to the router and look for IP addresses. If you're lucky you might see the IP of the router pop up.
Cheers
participants (3)
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A. Pagaltzis -
Camster342 -
Matt Brown