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If this link or this link reboots your router, you should probably also seek new firmware (or better firmware like dd-wrt/openwrt/tomato). It would be fun to embed those as invisible images on Google for a day...

http://192.168.100.1/Reboot.ht...

I have it bookmarked so I can freshen up the channels before I do a speedtest.
Pepper your blogs with this. People clicking it will lose their Internets for 45 seconds.

Hahaha! I use network 10.x.x.x because fuck you!

http://192.168.100.1/Reboot.ht...

I have it bookmarked so I can freshen up the channels before I do a speedtest.
Pepper your blogs with this. People clicking it will lose their Internets for 45 seconds.

I think that's not the IP address for the Motorola ( try http://192.168.100.1/ ), but for a Linksys wireless router, like say a WRT54G.

Actually, the 192.168.100.1 IP is only for Motorola surfboard modems.

Not true. My Arris telephony modem is the same address. My RCA modem I had before I got Comcast VOIP was also the same address. What generally varies is whether the information you want is on the index page. For the old RCA modem, all I got was a summary page telling me whether it was connected or not. I had to go to http://192.168.100.1/moreinfo.htm to get the signal data. Some modems have it on a page called diagnostics.htm.

The key to working with Comcast is to have some basic technical knowledge of cable internet. Once you show you know the lingo and you know the basic technical aspects, you'll either get the support person to "talk up" to your level immediately or switch you to someone that knows. Most support people have at least heard some of the terminology, usually enough to know if they're in over their head and need to route you to someone else.

For example, if you buy your own modem, NEVER say "I need my new modem INSTALLED." Say "I need my new modem PROVISIONED". 95% of the support people will know right away what you need and won't bother asking you about Windows and you'll be online 15 minutes later.

Know how to get to the status page of your modem (usually http://192.168.100.1/ but may vary depending on model). Know that your downstream signal needs to be between -10 and +10 dBmV. Know that your downstream SNR should be above 33. Know that your upstream power should be between +30 and +50 dBmV. When my signal dropped because of a splice in the line gone bad, I didn't tell Comcast "my internet don't work", I told them, "my downstream power is -16, which is out-of-spec, I need a tech to take a look at this". I had a tech out the very next morning and was back online by the afternoon.

Also, whenever you have a problem, BEFORE you call do the mantra of restarting your cable modem, router, and computer. Even if you know this will not fix the issue, do it. Then take the router out of the loop and do it all over again. Then when you call, tell them you did all this already. This will save time.

In all the times that I have had to call Comcast for technical issues, not once did the subject of Windows ever come up.

I'm on cable as well (Cox), and the account is associated with the MAC address of the modem, /not/ the MAC address of the computer, which gets its own IP address.

With some simplification, it works this way. (I talk about Ethernet below, but the USB interface is similar, within reason, of course.) They lock the account to the modem's MAC address. When the modem connects, after physically syncing, it asks for an IP address, of course giving the MAC address in the lower layer connection. If the modem's MAC address is registered, the assigned IP address (for the modem only) is a non-publicly-routable IP address (Cox uses addresses in the 10./8 range, but I'm not sure if that's DOCSIS specified or not, so it may differ elsewhere). That gets the modem online, but you can't yet connect, because your computer or router doesn't have an IP yet.

The modem, still setting up, then requests such things as the TOD (time of day) and a config file. The config file will contain the settings for your account, including your allowed bandwidth caps, which the modem then enforces (this is why the cablecos are so insistent on controlling firmware and the like, it can normally be flashed only from the cable side, because it's the modem that does the actual capping), and certain modem-side filters (port 80 inbound, among others, on Cox, for residential accounts). One particular config file setting of interest is the number of customer-side MAC addresses it can allow thru. Often, this is only one, but it may be more, if the account policy is set for more (many cablecos sell access for additional computers, really, access for more than one MAC address, for an additional fee).

If you have a Motorola Surfboard series modem (other brands have the interface, but lack the level of info on it that the Motorolas provide), surf over to http://192.168.100.1/ (which you may recognize is another non-publicly routable address), and on one of the pages, you'll see how many MAC addresses the modem has learned and how many you are allowed.

Then, after the modem is configured, it turns on the bridging mode between the Ethernet and RFC side and lets whatever is connected thru to the cableco and Internet -- but ONLY up to the number of allowed MAC addresses. It will "learn" the first MAC addresses it sees, ignoring any others on the LAN.

The caveat in switching MAC addresses should be apparent -- if you've already reached your configured limit (normally a single MAC address), in ordered to get your new MAC address to connect, you'll have to reboot the modem, because it learned the other MAC address and until that memory is erased, it won't allow any more thru to get IPs from the cableco.

Once your router or computer is allowed to connect, it will ask for and get an IP address from the cableco, normally the same one it got the last time it asked for an address, based on the MAC making the request. If the MAC is different, you therefore get a different IP address.

Thus, to force an IP address change, you change the MAC address you are using to connect, then reboot the modem so it forgets the old one and allows the new one thru. You should then get a new IP address. Eventually, the allotted IP addresses available for assignment will be used up, and the DHCP server will start reusing ones that aren't in use. However, that typically takes quite some time, because there's a significant number of "free" IPs, and because few people cycle MAC addresses. Thus, the system is likely to remember the MAC off your old Ethernet card you used a year ago, even tho it hasn't been connected since, and still give you the same IP address, unless of course you artificially set a different MAC address.

That brings us back to where we were before, the problem of setting a different MAC address. It's easier on Linux (and I believe the various BSDs) than on MSWormOS, but it should be possible in any case, even if you have to get a new NIC to do it. A router should make

malord may need a Motorola 484095-001-00 Signal Booster. Check your cable modem's internal webserver at http://192.168.100.1/ and if you do have a weak signal problem like I suspect (see Comcast's support forum and/or the Comcast forum on dslreports.com for how to do the diagnosis) then buy the amp. Yes, you shouldn't have to, but it's your best chance to actually fix the problem. Install the amp at the earliest possible point, before any cable splitters (if you have any).

If Comcast had any brains they'd keep a whole bunch of these in every Comcast service guy's truck and train their people to read the cable modem's signal status page. It'd be a helluva lot cheaper than repeated truck rolls to the same very annoyed customer. Better yet, they'd replace more of their aging copper with fiber before FiOS poaches all their best customers (alas, I'm in SBC/AT&T territory), but that's another rant entirely. Overall I'm reasonably happy with Comcast in my area but I'm still jealous of folks who can get FiOS.

How amusing (or abusing). Javascript AJAX style script to call those home firewalls or cable modems and abuse the poor end user. DOCSIS Cablemodems support http://192.168.100.1/ and many have diagnostic. I bet you could create a simple library that could regex the results of a javascript request to it and then reset the modem, etc. Plus all of those lovely DSL Modems and Firewalls with default passwords. Reminds me of the fun embedding modem control values in IRC commands. How long until hitting a web page has a chance of resetting your DSL modem, your cable modem, or your home firewall. Come visit my site at http://link/ removed]

My router (D-Link DI-704 UP) fakes the Telstra login process and feeds them the MAC address of one of my machines -- in fact, I find that it's more reliable than Telstra's client app.

Now that I think of it... I changed out the NIC in that box about a month ago and Telstra can't tell the difference. ;)

The only MAC address Telstra looks at is the one of your cable modem. Have a look at "HFC MAC Address" on http://192.168.100.1/address.html to see it. Only cable modems that have been registered with Telstra are allowed to connect, but you can use any computer/NIC you like, as long as it's running a login client or connected through a router that does.

One of the first things your modem does when it comes up is hit their TFTP server for a config file.
See here.

The Surfboard SB3100 already has NAT suppoort built into it so EVERYONE will be in violation. Go look it up for yourself, if you're on comcast then click this link which should show you some general info about your cablemodem. The cablemodem supports NAT on the 192.168.100.X network.

Skuld:
Ouch, mon.
Have you taken a look at your modem settings? just open your browser and point it to here.
you should be able to view up and down stream settings. Mine is at 128000bits...roughly 12K/s. Did the update on the cd, so at least I have email.

Bungie:
Dude, thanks for telling me. Too dang tired today. Had to stand on my head and shuffle around huge UPS batteries in addition to getting several more "shocks" to the system.
(not electric, but the "sinking...or is that syncing?--sorry, bad joke from the CMOS discussion--...feeling variety from the "didja hear about {fill in Oh, No! variety})

However, I think for a moment that it could be worse... I could be at the other end of the phone over at Charter/Cox/{whatever} dealing with people as furious, maybe moreso, than I am.

This whole @home thing, coupled with hardware failures (dell, naturally), delays in getting replacements, an ever growing pile of stuff I have to send back..and on and on.

Could be much, much worse.

.

I'm not sure it will help a lot of people, but this is what I just did to get reconnected. (Gotta feed the /. habit.) I'm in Fort Collins, CO if that's relevant to anyone. I haven't got a phone call from AT&T yet. But that may well be on account of the phone number they have listed for me is disconnected right now.

I did try sending out DHCP requests before doing this, but never got any replies. I wouldn't call this course of action exceptionally friendly behaviour. But the web sites AT&T listed in some email this past week are either unreachable or have nothing helpful.

• Listen for IP traffic coming over the modem. I did tcpdump -n -i eth0 and figured that the not-10.x.x.x router doing all the ARP requests was the neighborhood router.
• Make note of several of the IP addresses that the router continues to ask for and stop tcpdump. Also note the suspected router address.
• Set your IP address to one of the addresses from the previous step (see ifconfig(8) for help on that.) Add a default route through the router you found in the last step. route add -net default x.x.x.x )
• Hope someone follows up with a suggestion on getting DHCP working again or that you get a phone call from AT&T.

• You may well be hijacking someone else's legitimate IP address. And quite possibly violating your AUP in the process.
• Your cable modem does need to think it has a good connection to the network. Look for a set of lights glowing steadily. Or if it has a web interface, look at that. My RCA cable modem has a status page at http://192.168.100.1/

Good Luck!

For the record (and possibly losing my access over this..), I would like everybody to know that I have run Linux on the mediaone network since last September. I have only had one problem since then - and that was due to buggy firmware on the modem. If anybody has problems with their cablemodem displaying high-ascii garbage in the text fields.. Click on this link, which will reset your SB1200 cablemodem to factory defaults. Simply removing the garbage and re-entering the data will not fix it.

Caveat emptor people...

--

The SB1200 doesn't store the MAC address. Even if it did, all you need to do is open your browser and click on this link, which will reset your modem to it's factory defaults. This is also useful when the modem periodically fouls up and garbles all your configuration information (usually resulting in a "serial port error" whenever you try to connect).



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