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 Post subject: Internet connectivity issues
 Post Posted: Wed Jul 11, 2007 7:55 pm 
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Joined: Thu Jun 21, 2007 4:41 pm
Posts: 41
Location: OHIO, USA
Hi Scott,

Why do you have to put a DSL modem in bridge mode when attached to a router but not when a cable modem is attached to a router? I know why you have to put the DSL modem in bridge mode but I don't understand why there aren't DHCP issues when a cable modem is attached to a router. Anyway the real question is below.

You may remember my last post looking for testing devices for intermittent internet connectivity issues. I know you recommend using known good devices when troubleshooting and I agree with you but try asking a SOHO or home owner for their PPOE password so you can setup the test DSL modem. When I wrenched on the side I was very selective on what engines or jobs that I would take and now I am considering NOT taking internet connectivity issues because it is a fast way to loose money. I have one customer whose house is either in a black hole or built on an Indian burial ground because his wireless comes and goes and I cannot explain it. 2 linksys routers and calls to the cable company and it still drops. I cringe when he calls me. If a reasonably priced device does not exist then is there specific articles/training that I can gain more insight? Utilities? My personal laptop and ping -t are my arsenal as of now.

Thanks for your time.


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 Post Posted: Thu Jul 12, 2007 10:52 am 
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You are probably using "bridge" mode because the DSL modem you have is not
just a modem, it also has a built-in router. Placing the router in bridge
mode disables DHCP, essentially disabling the built-in router.

DSL companies started putting routers in their modems to prevent the problems
they were having with naive customers connecting the modems directly to their
PC without using a router (BAD idea), thus running without the NAT (Network
Address Translation) firewall a router provides. While adding the router was
a good move for customers that had no other router, it obviously complicates
things a bit for those that do.

The reason you haven't seen this issue with cable modems is that most cable
modems *don't* include a router, although there are now some that do such as
the Motorola SBG900:
http://broadband.motorola.com/consumers ... efault.asp

When using cablemodem/router combo with another router, you'd have the same
dual-router setup as you do with your DSLmodem/router combos.

BTW, another way to handle the dual-router issue is to use the one in the
modem (turn on DHCP), and disable the other router (turn off DHCP), thus
turning the 2nd router into a simple switch and/or WAP (Wireless Access
Point) instead.

But perhaps the best way to use two routers is to have them both actively
running in a nested connection, setup with non-conflicting addresses. I've
done this as a way to effectively create a network within a network, an
"open" one for guests, and a closed one for myself.

By connecting the second router to the first one you could set up two
networks (each with wireless access as well), the first using unsecure WEP
protection for guests (and crummy devices that don't support WPA), and the
second one with unbreakable WPA protection for sensitive files, systems, etc.
Any systems on the outer open network cannot "see IN" through the 2nd or
nested router, therefore any systems or shared files/printers on the nested
secure network are completely inaccessible to devices on the open network.

However, note that devices on the secure closed network CAN "see OUT" through
the nested router and access any device on the open network. This dual setup
also means that when a guest comes over and needs internet access, I only
have to give them an unsecure WEP key (or plug them into the open network
directly). I don't have to give them my secure WPA key, and whether they are
wired or wireless I don't have to worry about them accessing any of the
systems, files or printers on the closed network.

As for client network testing issues, again I'd stress that known-good spare
equipment is by far the most cost-effective test gear for individuals or
smaller shops.

Re: the password issue, I would tell the client in advance that you'll need
the password, or you'll have to charge them for the time it takes to call the
provider and have it reset on the job.

Once you identify a suspect component, merely replace it with the known-good
spare you brought along. If the replacement works, offer to sell them the
working equipment as the solution (I recommend charging at least a 25% markup
on all hardware and software you sell). If they refuse, then simply charge
them for the diagnostic time, and remind them that future work on the same
problem will be billed by the hour, which can add up fast.

As for the "black hole" wireless problem, that is probably caused by
interference on the 2.4GHz band from cordless phones, microwave ovens, other
wireless networks, bluetooth devices, radio transmitters, etc. The best
solution in that case is a switch them over to the 5GHz band using an 802.11a
WAP and NICs. Have a set with you so you can demonstrate functionality, then
once you demonstrate that it works, sell it to 'em. Sure the 5GHz stuff is
more expensive than 2.4GHz, but the 5GHz stuff works where the 2.4GHz doesn't.
Scott.


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 Post subject: Re: Internet connectivity issues
 Post Posted: Tue Aug 04, 2009 10:27 am 
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Joined: Wed Jun 17, 2009 1:26 pm
Posts: 19
Location: Grenada
I have a customers with internet conectivity problems.
Their pcs are not getting an ip adddress from the modem/router
I tried reinstalling the Network card driver even installing a new NIC but same problem.
assist me please


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 Post subject: Re: Internet connectivity issues
 Post Posted: Tue Aug 04, 2009 11:24 am 
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Follow the troubleshooting steps in the following articles:


If you are running XP, I recommend using the enhanced Network Diagnostics Tool for Windows XP (similar to that included with Vista).

In your it sounds like the problem is with the router. I'd try resetting it to factory defaults, if that doesn't help, then try replacing it with a known-good spare. Let me know what the problem turns out to be. Scott.


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 Post subject: Re: Internet connectivity issues
 Post Posted: Fri Sep 25, 2009 11:33 am 
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How do you set a DSL modem to bridge mode? Ive got a Motorola style MSTATEA modem.


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 Post subject: Re: Internet connectivity issues
 Post Posted: Fri Sep 25, 2009 1:03 pm 
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Most likely you would go into the Modem's settings menus, then find and change the operating mode setting to "Bridge". Without a link to your modem's manual, I can't tell you exactly where in the menus that setting would be, or exactly what it would be called. For example, on a Linksys WRT54G router, the mode setting is in the Advanced Routing page, where you would change the Operating Mode setting from Gateway (router mode) to Router (bridge mode). As you can see, the Linksys terminology is confusing. <g> Scott.


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 Post subject: Re: Internet connectivity issues
 Post Posted: Fri Sep 25, 2009 1:57 pm 
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I went poking around in the modem's settings but could not find any bridge options. It's a Motorola model 2210-02-1002. It's an ATT DSL standard modem. All I could find on the net were headaches regarding this modem. ATT has not even issued a firmware update since it was introduced. I want to go wireless with my DSL but this modem is getting in the way.


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 Post subject: Re: Internet connectivity issues
 Post Posted: Fri Sep 25, 2009 2:27 pm 
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Randy,

Just plug your router into the modem and go. You can have a router behind a router no problem at all, your router will get all the information it needs from the dsl modem/router.

As a matter of fact, I've set up a network with 3 routers. The first router is the main router which I plug 2 other routers into. I then have 2 seperate networks that cannot see each other. I leave the one with the wireless turned on wide open for guests that come over. The other network is mine and is secure.

Mike


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 Post subject: Re: Internet connectivity issues
 Post Posted: Fri Sep 25, 2009 2:48 pm 
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I tried that but got no internet connection. From the blogs I've read everybody else is having the same problems with the ATT modem. Do you know of any DSL modem/router combos?


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 Post subject: Re: Internet connectivity issues
 Post Posted: Fri Sep 25, 2009 3:27 pm 
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I'm guessing you checked the router after setting it up to see if it is acquiring an ip address from the modem.

If you cannot get it to work, you could always set the router to bridge mode and let the wireless clients pick up ip addresses from the modem, that should work.


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 Post subject: Re: Internet connectivity issues
 Post Posted: Fri Sep 25, 2009 5:55 pm 
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Would this help you out Randy?,


http://broadband.motorola.com/consumers/products/2210-02/downloads/2210-02_UserManual.pdf


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 Post subject: Re: Internet connectivity issues
 Post Posted: Fri Sep 25, 2009 6:53 pm 
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That manual only has the basics, I think he is looking for this: http://www.netopia.com/support/hardware ... 7-Clsc.pdf

Information on how to configure bridge mode is on page 117. Scott.


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 Post subject: Re: Internet connectivity issues
 Post Posted: Tue Sep 29, 2009 6:11 pm 
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Thanks FatGuy/Scott,

It will be a while before I can put this info to the test. I'll be attempting to upgrade to "N" wireless in October. I'm looking at Linksys because Cisco bought them and Cisco has a pretty good presence at most Internet hubs all over the world. I'm hoping some of their quality trickles down to their consumer devices.

Scott, do you have any opinion on Linksys or some other brand?


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 Post subject: Re: Internet connectivity issues
 Post Posted: Tue Sep 29, 2009 7:20 pm 
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I've used and recommended Linksys products in the past, however I haven't tested many 802.11n routers or access points, so I can't give any specific recommendations in that area. Note that 802.11n was just recently ratified (finally!), however all of the current products I see are still at the "Draft 2.0" level. Ideally I'd want a wireless router that supported the final 802.11n spec., with dual-band operation in a 3x3:3 (transmit antennas x receive antennas : spatial streams) configuration supporting up to 450Mbps, and with external antennas for maximum range. Unfortunately I don't know of a router like that, however for a laptop internal adapter with those capabilities I'd recommend the Intel WiFi Link 5300.

Let me know what you end up using and how well you like it. Scott.


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 Post subject: Re: Internet connectivity issues
 Post Posted: Sun Dec 20, 2009 8:50 pm 
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Update:

The Motorola modem issue is now moot. It keeps losing the internet connection and also the DSL light keeps going out. Unplugging it for 5 min. and reattachng the power plug offers temporary reconnection but I feel the modem is on it's way to the modem mortuary.

I replaced the modem with modem/router (DLink DGND3300). This was by far the easiest to set up networking device I have ever encountered. I highly recommend it. I'm runnng it in mode 2 (single band g/n mode only). I could switch to dual band later but I got a couple of USB g adapters at Lowe's for $8 each on closeout so this was the way to go for me. I had 4 out of 5 computers online in 30 minutes.


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