Re: [gentoo-user] [OT] Interrogate network for devices
On Sunday 10 February 2008, [EMAIL PROTECTED] wrote: Sorry for the OT, but unable to raise anyone at comcast right now. I think I recall having read somewhere that one can do something to discover what devices are on a network (Home lan). And what there addresses are. You are looking for route and arp commands. However, if you are not part of a network all you might see is your PC's loopback entry - the arp and routing tables will be empty. I've recently switched from DSL to Cable connection but still have both working currently. I had assumed my netgear-firewall/router would find the Cable modem and be able to talk to it, but that isn't happening. This could be for a number of reasons. Is the cable modem a pure modem, or is it also a router? Is authentication to the ISP's network configured at the PC, or is it configured at the modem? If the authentication is configured at the PC/client end rather than the modem, then you are probably not using the correct encapsulation for the cable network and, or have not cloned/spoofed the MAC address of the nominated client (your PC). I guess that your ADSL will be using PPP over ATM (PPPoA), if it's anything like what we have in most of the UK, while your cable is most likely using PPP over Ethernet (PPPoE). In any case, you will need to change the respective settings in your Netgear router. BTW, which router is it? If it is one of the DG834 domestic models, these have both (ADSL) modem and router combined into one unit. Again, depending on whether your cable modem acts as a bridge or as a client on the Comcast network you may or may not need to set up authentication on the router side (in the Netgear modem configuration). I can connect the cable modem direct to a pc and using the software that comes with it establish a connection to the internet, but I wanted to have that firewall/router in between the cable modem and home pcs. But that is only on a windows machine. That should not stop you finding out what IP address the PC uses to connect to the modem and if needed what the MAC address of the PC's NIC is that Comcast has registered as a legitimate client. Go to My Connections and select the NIC being used to connect to the modem and then click on Status/Support and note what the IP Address: shows. If this a private reserved LAN IP address then check what the Default Gateway: IP address is. Use that in a browser, or telnet console to connect to your modem. If however this is an Internet address then this won't be good for connecting to modem, which is now acting as a bridge to the ISP's network - the IP address is served by your ISP's dhcp server. Another way to find out what IP addresses are being seen by the PC is to go to Run and enter ipconfig /all. Note the IP Address: and Default Gateway: as above. Also note the MAC address (this is called Physical Address). In summary, enter the MAC address into your Netgear router and try to connect without authentication, in the hope that the cable modem deals with that. If this does not work, then also enter the username/passwd and select PPPoE for encapsulation. In both cases select dhcp as opposed to static IP on the router. The help file that comes with the modem provides no information about how one talks to the modem. No ethernet address is supplied. However it is an ethernet device and connects to the pc with ethernet cable. Apparently comcast felt it wiser to provide no details and let its software do the connecting. This is because the vast majority of users out there will never want or be able to connect to the modem. The few who connect could well mess it up and raise fault tickets unnecessarily. So Comcast are trying to reduce user generated errors proactively. But can't I learn the IP address (inward facing) of the modem? The IP from outside is of course visible to ipconfig, when connecting to internet from a windows machine thru the cable modem, but I see nothing that indicates what its lanside ethernet address is. Its obviously connecting to the pc with dhcp so setting the netgear to listen for dhcp seemed like it should work... but doesn't. See above regarding the MAC cloning and authentication encapsulation. I thought I would be able to connect to the cable modem with a browser and maybe learn enough to make the netgear router/firewall connect to it, or one of my gentoo boxes, so have tried a few of the semi-standard addresses other ethernet hubs/routers etc default to, like 192.168.0.1, 192.168.1.1 and a few more. Have you also tried: 192.168.1.254 and .255 10.10.10.1 and 10.1.10.1 BTW, before you try to connect to any of the above first change your Gentoo's IP address statically, by running as root: ifconfig 192.168.0.2 The exact number is not important as long as it is in the same subdomain (e.g. 192.168.0.0) and it does not conflict with the expected LAN IP address of the router. A quick
Re: [gentoo-user] [OT] Interrogate network for devices
On Sun, 10 Feb 2008 12:55:49 + Mick [EMAIL PROTECTED] wrote: On Sunday 10 February 2008, [EMAIL PROTECTED] wrote: If the authentication is configured at the PC/client end rather than the modem, then you are probably not using the correct encapsulation for the cable network and, or have not cloned/spoofed the MAC address of the nominated client (your PC). I guess that your ADSL will be using PPP over ATM (PPPoA), if it's anything like what we have in most of the UK, while your cable is most likely using PPP over Ethernet (PPPoE). In any case, you will need to change the respective settings in your Netgear router. BTW, which router is it? If it is one of the DG834 domestic models, these have both (ADSL) modem and router combined into one unit. Again, depending on whether your cable modem acts as a bridge or as a client on the Comcast network you may or may not need to set up authentication on the router side (in the Netgear modem configuration). Unless your comcast connection differs from my own, you won't need to authenticate. Instead, they should have recorded your modem's MAC address. AFAIK we use ppp-oe for (a)dsl here in the states, and all cable modem connections I've ever seen have been transparent (though no doubt they use some sort of ppp as well) -- gentoo-user@lists.gentoo.org mailing list
Re: [gentoo-user] [OT] Interrogate network for devices
[EMAIL PROTECTED] wrote: Sorry for the OT, but unable to raise anyone at comcast right now. I think I recall having read somewhere that one can do something to discover what devices are on a network (Home lan). And what there addresses are. I've recently switched from DSL to Cable connection but still have both working currently. I had assumed my netgear-firewall/router would find the Cable modem and be able to talk to it, but that isn't happening. I can connect the cable modem direct to a pc and using the software that comes with it establish a connection to the internet, but I wanted to have that firewall/router in between the cable modem and home pcs. But that is only on a windows machine. The help file that comes with the modem provides no information about how one talks to the modem. No ethernet address is supplied. However it is an ethernet device and connects to the pc with ethernet cable. Apparently comcast felt it wiser to provide no details and let its software do the connecting. But can't I learn the IP address (inward facing) of the modem? The IP from outside is of course visible to ipconfig, when connecting to internet from a windows machine thru the cable modem, but I see nothing that indicates what its lanside ethernet address is. Its obviously connecting to the pc with dhcp so setting the netgear to listen for dhcp seemed like it should work... but doesn't. I thought I would be able to connect to the cable modem with a browser and maybe learn enough to make the netgear router/firewall connect to it, or one of my gentoo boxes, so have tried a few of the semi-standard addresses other ethernet hubs/routers etc default to, like 192.168.0.1, 192.168.1.1 and a few more. I'm not sure if this will work for you or not but it worked for me when I was at my ex's and we had cable there. Cut everything off. Turn on the modem and wait a minute or two after the lights stop changing and blinking. Turn on the next device, router in our case, and wait a few minutes again. Then turn on the computers. I always cut on the one hooked to the ethernet #1 port first but it may not matter. That was my Linux box and it was always on, 24/7. I also had to change the IP address on the router to a fixed address to get it to work right. I think I had it set to 192.168.100.2. After that, we had very little trouble with the connection. The modem itself was 192.168.100.1. If you hook your computer directly to the modem, you can see things like signal strength and stuff. Can't change anything tho. You just get to look. I think it had like a reset button too. Also, if I had anything between the computer and the modem, I could not see the modem at all. YMMV. Oh, we had Vista-Media to. If that matters any. May not help but may be worth a shot in the dark. Dale :-) :-) -- gentoo-user@lists.gentoo.org mailing list
Re: [gentoo-user] [OT] Interrogate network for devices
On Sun, 10 Feb 2008 21:52:14 -0600 Dale [EMAIL PROTECTED] wrote: I also had to change the IP address on the router to a fixed address to get it to work right. I think I had it set to 192.168.100.2. After that, we had very little trouble with the connection. The modem itself was 192.168.100.1. If you hook your computer directly to the modem, you can see things like signal strength and stuff. Can't change anything tho. You just get to look. Interesting! I wonder if mine had a utility for something like that on the disks that I didn't bother to open that came with the modem In this case it sounds a lot like a DMZ kind of thing, right? I see DSL doing that a lot of the time. Often you can also turn it off and use it as a dumb ppp or such. Other times, your stuck behind it and may not even be able to forward ports. Or maybe it's something different, something I haven't seen. -- gentoo-user@lists.gentoo.org mailing list
Re: [gentoo-user] [OT] Interrogate network for devices
Dan Farrell wrote: On Sun, 10 Feb 2008 21:52:14 -0600 Dale [EMAIL PROTECTED] wrote: I also had to change the IP address on the router to a fixed address to get it to work right. I think I had it set to 192.168.100.2. After that, we had very little trouble with the connection. The modem itself was 192.168.100.1. If you hook your computer directly to the modem, you can see things like signal strength and stuff. Can't change anything tho. You just get to look. Interesting! I wonder if mine had a utility for something like that on the disks that I didn't bother to open that came with the modem In this case it sounds a lot like a DMZ kind of thing, right? I see DSL doing that a lot of the time. Often you can also turn it off and use it as a dumb ppp or such. Other times, your stuck behind it and may not even be able to forward ports. Or maybe it's something different, something I haven't seen. I'm no guru on this thing but for some reason the DHCP part in the Linksys router would just not accept the address from the modem. Sort of weird in a way tho. Since I use Linux only, I never installed any software. I just pointed my browser to that address and up it popped. That would work when looking for the modem or the router. Tho I could not get to the modem if the router was in the middle. Not sure what the deal is on that. If I had access to one I'd get you a screen shot or something but like I said, that was my ex's thing. She is still mad that I left. She had issues that I couldn't deal with. Ya know. ;-) Dale :-) :-) :-) -- gentoo-user@lists.gentoo.org mailing list
Re: [gentoo-user] [OT] Interrogate network for devices
Perhaps you need a cross over cable between the modem and the router? -Hal [EMAIL PROTECTED] wrote: Sorry for the OT, but unable to raise anyone at comcast right now. I think I recall having read somewhere that one can do something to discover what devices are on a network (Home lan). And what there addresses are. I've recently switched from DSL to Cable connection but still have both working currently. I had assumed my netgear-firewall/router would find the Cable modem and be able to talk to it, but that isn't happening. I can connect the cable modem direct to a pc and using the software that comes with it establish a connection to the internet, but I wanted to have that firewall/router in between the cable modem and home pcs. But that is only on a windows machine. The help file that comes with the modem provides no information about how one talks to the modem. No ethernet address is supplied. However it is an ethernet device and connects to the pc with ethernet cable. Apparently comcast felt it wiser to provide no details and let its software do the connecting. But can't I learn the IP address (inward facing) of the modem? The IP from outside is of course visible to ipconfig, when connecting to internet from a windows machine thru the cable modem, but I see nothing that indicates what its lanside ethernet address is. Its obviously connecting to the pc with dhcp so setting the netgear to listen for dhcp seemed like it should work... but doesn't. I thought I would be able to connect to the cable modem with a browser and maybe learn enough to make the netgear router/firewall connect to it, or one of my gentoo boxes, so have tried a few of the semi-standard addresses other ethernet hubs/routers etc default to, like 192.168.0.1, 192.168.1.1 and a few more. -- gentoo-user@lists.gentoo.org mailing list
Re: [gentoo-user] [OT] Interrogate network for devices
On Sat, 09 Feb 2008 22:29:15 -0600 [EMAIL PROTECTED] wrote: Sorry for the OT, but unable to raise anyone at comcast right now. Really? I didn't think that was possible... although sometimes it's good to call twice, get another opinion. I think I recall having read somewhere that one can do something to discover what devices are on a network (Home lan). And what there addresses are. the network devices of those boxes have fc1918 private addresses i'm sure. even if your router would forward packets from the outside in (which can usually be configured), comcast isn't going to route them to your router. your external address is, of course, somewhat available, and the device listening to that address (your router) is therefore potentially vulnerable. Run a good firewall and you'll have knowledge of what happens to incoming connections (generally, it would be best to ignore them). linux makes a very good firewall. I've recently switched from DSL to Cable connection but still have both working currently. smart! I had assumed my netgear-firewall/router would find the Cable modem and be able to talk to it, but that isn't happening. i've never heard of that happening. ... I can connect the cable modem direct to a pc and using the software that comes with it establish a connection to the internet, but I wanted to have that firewall/router in between the cable modem and home pcs. In my experience (w/ comcast), you connect the modem to a network port via ethernet and then request a dhcp address. I never used comcast's software in windows or linux. But that is only on a windows machine. The help file that comes with the modem provides no information about how one talks to the modem. No ethernet address is supplied. However it is an ethernet device and connects to the pc with ethernet cable. Apparently comcast felt it wiser to provide no details and let its software do the connecting. It's more transparent. The network device on the modem holds your public ip address. The modem has nothing to say. Some modems, no doubt, have built-in gateway/router/firewalls, but not all. But can't I learn the IP address (inward facing) of the modem? The IP from outside is of course visible to ipconfig, when connecting to internet from a windows machine thru the cable modem, but I see nothing that indicates what its lanside ethernet address is. It doesn't have one. (If it did, you'd need to use it to reach the outside.) Instead your outside ip is 'on' the computer itself. Its obviously connecting to the pc with dhcp so setting the netgear to listen for dhcp seemed like it should work... but doesn't. the modem doesn't do the dhcp though, the computer asks and a dhcp server in comcast-land gives out a lease. i would think your router supports it - but you'd be using dhcp to request a lease from netgear's point of view, not listening. 'listening' for dhcp sounds more like serving addresses on the local network than using dhcp for external configuration. I thought I would be able to connect to the cable modem with a browser and maybe learn enough to make the netgear router/firewall connect to it, or one of my gentoo boxes, so have tried a few of the semi-standard addresses other ethernet hubs/routers etc default to, like 192.168.0.1, 192.168.1.1 and a few more. as i said, it probably won't have such an address. it is transparent to everyone but comcast itself, which evidently delivers some sort of point-to-point-like service . but the good news is gentoo _should_ be able to use it just fine. i didn't have any problems. the netgear should do fine as well, i'm surprised you're having problems at all. well, i hope that helps. feel free to contact me if you have any more questions. -- gentoo-user@lists.gentoo.org mailing list
