Tuesday, August 16, 2005

I'm in the process of getting ADSL connected.

I put up with ISDN for a long time, and I'm really sick of it. 64k is no great increase over 56k dialup, and I think the ISP I was using for my ISDN account is really crap, half the time their service is as slow as a 28k dialup.

When I wasn't at home, this was fine, since I wasn't using the connection interactively, it was just to keep my TiVo's guide data up to date etc, and allow me to access my email archives remotely.

Now that I've started working from home, I decided to get ADSL. The reason I put this off for so long, was that I didn't want to have to deal with Telstra coming out to convert the ISDN back to analogue, and then get ADSL provisioned on it.

So anyway, I put in the call to get the line converted back.

I immediately put in an ADSL install order, with WestNet, but this was rejected, because I showed as having an incompatible line.

I called them up, the support's terrific, I was immediately speaking to a real person, and I explained the situation.

The guy got the rejected application back, resubmitted, it, and put a hold on it, until I contacted them, to let them know that the line was back to analogue.

Telstra turned up 5 days later to do it. They charged $150 to convert it back.

The tech came out, ripped the NT1 unit off the wall. I told him not to bother connecting the second phone line to anything, since the only point it had is right next to a point on the first line.

He didn't listen, and did a dodgy job of patching the second line into the first line. At some point I'll just rip it off again, or perhaps rip all the other points off, and install a central ADSL filter.

(Upon thinking about that later, that wouldn't work, because the phone line comes in off the street, into the roof space, and there's a splitter, with quite a few lines coming off it there. Only one of those lines goes to the kitchen, so I don't know why Telstra insisted on installing the NT1 there, since it's not the first run from the street).

Once the guy was finished, he told me to wait until the end of the day, or the next day, for the ticket to get updated, so the line would show as an analogue line again.

I called up WestNet again the next day, and let them know about the resubmitted application. The woman checked, and it all seemed to be ok.

I asked about a dialup account, since I didn't have any access now, that I didn't have an ISDN line anymore.

The woman told me that they'd give me 200 hours of dialup free, while I waited for the ADSL to be installed.

I didn't need to provide a username or password, they already had those, from the application I had submitted.

I hung up, and immediately realised that I didn't have the dialup number. That's the only thing I can fault with their support.

I SMSd my mate down in Melbourne, and he found it for me, and SMSd it back to me, and I got online with dialup. It was a ton faster than the ISDN ever was. Pathetic.

I dug out an ADSL modem/router I got about 18 months ago, a Netcomm NB1300. I discovered that the power supply for it (12v, 800mA, AC(!)) wasn't in the box. Great.

I haven't done anything with this device for over a year, when I last tried to install it at a mates place, when he discovered his Telstra supplied SpeedTouch had died.

I must have left the adapter around there at some point, over a year ago. This mate is someone on MSN, who I can chat to now, so I asked him about it, he didn't recall ever seeing it.

Eventually I found it, at home, in a box of assorted AC/DC adapters. I found a 48v adapter while I was looking, God knows what that's from.

Anyway, I powered the modem up, and went about configuring it.

First thing, I had no idea what the default IP on it was. I googled for that, finding that it's, and discovered that there's a security flaw with the NB1300, detailed here.

Basically, you can ftp to the device, login with the default admin login/password (which I didn't know yet), download the config file, and the ADSL username/password are stored in plain text in it.

Next thing was to find the admin login/password for it (since I couldn't remember it), but the default passwords page had it.

(I was sent a couple of links to password pages by a guy I went to TAFE with a few years ago, when I was chatting to him a few days ago, they're here (so good I downloaded it) and here ).

I tested the flaw, yep, I was able to login, and download the config file, and the username and password were in plain text.

I notice that Netcomm have updated to "fix" this problem though, when I checked the port forwarding config in the web interface, I saw that they've just port forwarded ftp and telnet on the WAN port to a useless internal address.

After that, I went about trying to configure the NB1300 to connect to my ADSL, when the line gets provisioned (I haven't been contacted about that yet).

I wasn't sure of the settings I need to enter, so I went to search Westnet's support. I couldn't find anything related to the NB1300 in their knowledge base, only that they port filter incoming traffic, which can be used to exploit another security flaw in the NB1300. (Maybe I don't want to use this thing after all).

While I was looking in there, I noticed an article about configuring a Cisco modem/router (here, hopefully the link works). I've also got one of those, a Cisco 675. I never had any luck with it before. I got it off a guy who'd bought a stack of them, off eBay, from the US, to sell cheap here.

He didn't think they worked here after that, because you couldn't set the correct VCI/VPI settings for most providers in .au (8 and 35).

The Cisco 675 conveniently has a different management port pinout than every other Cisco device, so a standard Cisco console cable doesn't work. I dugout the 675 again (I'd found the power supply for it down the back of the desk a couple of days ago).

I'd come to the conclusion that the device was stuffed, when I'd mucked around with it before, almost 2 years ago. When I checked the pinouts on the special console cable, it didn't seem right for the 675 anyway.

I found a page with the pinouts for the 675, here, so I made up a new cable, with the correct pinouts.

I tried to test this on my laptop, with the USB -> RS232 adapter I've got (a "Prolific 2303" IIRC), but again, I couldn't get anything in minicom, even with the RX/TX lines shorted.

I plugged it into the Cisco anyway, to find that all I'd get was an accented y character as I plugged the cable in/out. I couldn't get a prompt, or anything.

I wondered if it was something to with the serial adapter, even when the RX/TX lines on the adapter are shorted, you don't get loopback, like a proper serial port does.

I decided to try it with a real serial port, but that didn't make any difference. The loopback test worked, so I had the pinouts right, but the 675 still did nothing.

I figure the thing is dead. If anyone wants it, you can have it, just ask.

After that, I went back to the NB1300. After reading about security flaws all over the place, I decided to update the firmware.

I downloaded the new one off the support site, the page specific to the NB1300, here.

I didn't realise this was actually a zip file, because clicking the download button just sends you "NB1300", and because it had no extension, I assumed it was the image file to load into the modem (oops).

I tried loading this, and it didn't look like it worked. I wondered what the file actually was, so I opened it up with a hexeditor, and found the first couple of bytes to be "PK". Hmm, this is a zip file (PKZIP).

I unzipped it, and found an image file, and the release notes. I had another go, this time uploading the image, which looked a bit more promising.

I rebooted the router, and it came back up, but still had the same settings as before, like my mate's ADSL username and password.

It was also telling me that the ADSL module wasn't loaded, and that there were undefined symbols. Something's not quite right here.

Hmm, I'd read that you need to reset the device to factory settings before/after flashing, and I hadn't done that.

When I got around to resetting the device, assuming that you just hold the reset button in for 3 seconds or so while you turn the device on, I discovered that it was now b0rked, and wouldn't boot up.

(Apparently the correct method to reset the device, is just to hold the reset button in for 10 seconds, and it will reboot, and reset itself to factory defaults, and it doesn't mention anything about holding the button in while turning the unit on).

I'd tcpdumped my laptop's ethernet interface with the modem attached directly previously, and saw that the modem arp'd - when it powered up, and it wasn't doing that anymore.

The lights didn't look good either, just power, and ethernet/100mb link LEDs on. The ethernet activity LED would flash if I tried to ping the modem, but it wouldn't respond.

I googled around, and found that this is fairly common, with the NB1300s. There's a forum about it here, and a page describing how to fix it here.

You'll need to download the rar file linked to at the top of the fix page.

It looked a bit complicated, pull the modem apart, short a jumper, boot a pc up, that's got an Intel chipset, and a USB1.1 controller.

I went through, following the instructions (pulled the modem apart, shorted the jumper, in a different location than in the doco), but it'd be a bit hard for me to use winimage on linux. I started out by just using dd to write the IMZ boot floppy image to a floppy, but this wouldn't boot.

I also tried to burn the CD as bootable with the IMZ image on it, but mkiso was erroring on that. I discovered why, it's because an IMZ file is actually a zipped disk image (hence the Z).

unzip was able to decompress the IMZ file, and I ended up with an IMA file. I tried again with dd, to image a floppy, which was a lot more successful.

I booted up my old PII333 machine (with Intel chipset, and USB 1.1 controller) with the properly imaged floppy, and the CD you have to create.

It took a while to boot, but eventually the menu came up. I started going through, attached the modem, via both USB and ethernet to my PC (I don't know why you need both).

When told, I powered it up, the floppy initialised the USB controller in my PC, saw the modem attached, and wiped the flash memory, no errors. Good.

After that, it flashed the flash memory again (with a quite old firmware), the LEDs flashing as they are supposed to.

I continued following the instructions, powered off the modem, removed the jumped I'd installed, unplugged the USB, waited a minute, powered it up again, and waited for a couple of minutes.

Eventually the LEDs were back flashing properly again, as they were when I was able to access the device properly, this looks quite promising.

I went over, turned the modem off again, moved it back over near my laptop, and plugged it in again/turned it on.

I tcpdumped the interface again, and I saw it arping - again. Woo!

I accessed the web interface, up and running, back to factory defaults. The repair rar comes with a firmware, newer than the one flashed as part of the repair, so I loaded that in, which looked more successful than the one I tried to load from Netcomm's support page.

I wasn't game to try loading the one I got from Netcomm again, in case I have to go through the whole repair thing again.

That's it for now, until I get contacted that the line has ADSL provisioned on it I think.

Oh, actually.. I intend to build a box running IPCOP, and put the modem in "bridge mode",and rely on IPCOP to do the authentication, instead of having to muck around with port forwarding in the modem.

I found a couple of pages about running the modem in half bridge and full bridge modes. I'll probably end up in full bridge mode.


Post a Comment

<< Home