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DHCP failing-New Firmware-Macs-Airports and Power Outage


DHCP failing-New Firmware-Macs-Airports and Power Outage

I have had a 3800 HGV-B delivering broadband for almost a year and a half... Both wired and wireless working great with all my Apple gear.  Upon returning from vacation, we had a couple of power outages running as long as 4 hours.  I had not been using the system so don't know if these are relevant.  Yesterday, I noticed my wireless not working and began my normal trouble shooting.  Basically, shut everything down and began bringing everything back up starting at the 3800 and working downstream.  Right away I noticed that my Time Capsule did not get the green light and the message was that it failed to get an IP address. What happened next is a sad story of reboots, connecting directly to the 3800 and getting all kinds of weird dysfunctional results. My time capsule worked when directly connected to the 3800 but did not when I connected to it through my house Ethernet network.  Somewhere in here I took a look at to see if it's settings got scrambled.  Right away I noticed that the web page had changed and guessed that I had been force fed a firmware update.  Now is probably a good time to detail out my setup (that was working fine before I left for vacation).

HGV3800-B with wireless turned off and CAT5 connection to

GE 10/100 6 port switch with CAT5 connection to Ethernet outlets throughout the house

Airport Extreme (Time Capsule) connected to Ethernet set to Bridge Mode and creating a wireless network

Airport Extreme G connected to Ethernet same setup as with Time Capsule just on another floor

G4 Powerbook with both wireless and wired capability (wireless at time of problem showing up)

G4 Mirror door Desktop with both wireless and wired capability (wired to the Time Capsule at time of problem showing up)


I did finally get the laptop connected by wire so am able to post this cry for help.


I am trying to figure my best course of action.  I did notice the posting about disabling the WPS on the 3800 and tried that to no avail.


Here are some of the options I am considering.

1) Under Devices to Clear the list... My hope is that this would clear out any stuck IP addresses and would cause the 3800 to serve up new, unique IPs as I booted the network back up.  This seems simple but does not bode well for the future... I should be able to wander about the house with my laptop and switch between wired and wireless or have a power outage and have the DHCP server reclaim and reassign IPs without having to do this. The warning on the page insinuated that bad things could happen if I did this without a tech holding my hand.


2) Follow the instructions posted by computerJoe to effectively disable routing by the 3800 and use my Airport Time Capsule as my router.  I am a little worried that the new firmware may have changed  up how this is done... His advice was in January and this firmware thing happened here in May.


3) Call ATT and ask them to trade my 3800 for a modem only.  I cut the cord on the cable part of my service a month ago and do not need the fancy box.  I would prefer this option because I would rather use my Apple gear to do the routing job. I list it last because I think I would spend hours on the phone with support and they would not go for this... that basically I need to get rid of my Apple gear and use the 3800.  This is not going to happen... the Apple gear is here to stay even if it means me changing to another provider.


I sure hope one of the geeks on this forum sees this and has some good advice.



Message 1 of 8

Re: DHCP failing-New Firmware-Macs-Airports and Power Outage

The 3800 has to stay, it is the only device available for U-Verse service.  (Actually, for new customers who are Internet-only, they are sending a 3600, which is basically the same router as the 3800 but doesn't have the coax or VOIP connections).


You might try to reset the 3800 to factory defaults, this can clear up configuration problems.  There is a small red button on the back, press it down and hold it down for 10 seconds, this should clear all configuration settings and return everything to factory defaults.  Start from that point and see if it doesn't behave better.  Be aware that you'll have to put your Apple router back as the DMZ device after this is done.


Message 2 of 8

Re: DHCP failing-New Firmware-Macs-Airports and Power Outage

SomeJoe7777 great  advice.  I am ready to roll except I don't really understand "put your Apple router back as the DMZ device".  I do recall turning off the radio on the 3800 and putting the Apple base stations in bridge mode.  Can you give me a clue or link that explains the DMZ settings... where they are etc.

Message 3 of 8

Re: DHCP failing-New Firmware-Macs-Airports and Power Outage

I reset and the network failed with same symptoms as before. 

This will not work:

3800 to switch with wireless off

switch to airport base (bridge mode)

The airport self assigns IP


This sort of works

3800 to airport base (wireless off on 3800, bridge mode on airport)

airport base to switch

switch to laptop as I walk around the house plugging it in.... oops 2 worked and one didn't.


I am starting to think that part of the problem is a fried switch.  But... I absolutely don't get it that putting  the switch between the 3800 and the airport base should make any difference at all for the part of the switch that is working.... a long time ago I remember something about normal CAT5 and cross over CAT5 but I don't think modern devices care about this.

Message 4 of 8

Re: DHCP failing-New Firmware-Macs-Airports and Power Outage

Well, some switches are auto-MDI/MDIX (meaning that they automatically figure out if they need to operate as a normal port or as a crossover port).  This is standard on Gigabit switches, but only some 100 Mbps switches have this.  The RG (2Wire 3800HGV) does not.


You'll have to forgive me, I've never worked with Apple stuff, so I don't know the capabilities of your Apple routers.  But you mentioned earlier that you'd actually like the RG to operate as a straight modem.  If you want to do this and operate your Apple router as a router instead of a bridge, see this thread on DMZ setup.  That thread uses a Linksys router as the router behind the RG, but your setup would be similar.


DMZ is a setting on the RG that will basically assign the external IP address to your router.  This is as close to operating the RG as a modem that you can get.


Be aware that if you have STB/DVR boxes for TV service, those still have to be directly plugged into the RG, they can't plug into your router.


Message 5 of 8

Re: DHCP failing-New Firmware-Macs-Airports and Power Outage

As with what Joe said and on your AEBS in airport utility create a wireless network set security WPA/WPA2 it works better

and manually select the channel auto never works right for extended use. Connect using ethernet and next line under connection sharing select off (bridge mode) and under TCP/IP configure IPv4 using DHCP.

Message 6 of 8

Re: DHCP failing-New Firmware-Macs-Airports and Power Outage

Thanks for the reset advice and the directions to get to a near modem setup.  I was right about suspecting my switch... picked up a new switch today, plugged everything in the "old" way and it worked perfectly.  I was caught out by the intermittant nature of the switch malfunction.  This is both good and bad news.  That danged GE 10/100 switch fits in my "home security box" but comes at a huge premium.  Will just have to see if I get any milage on the switch being 14 months old at time of failure.

After the dust settles a bit, I will go follow the link and set the 3800 up in modem mode.

Thanks again!

Message 7 of 8

Re: DHCP failing-New Firmware-Macs-Airports and Power Outage

bless you SomeJoe7777.  I am new to att uverse and i tried the customer support but they could not help by reading their script.  i read your posts here and regarding how to set up DMZ and successful.    i have apple products and wanted the gateway to act as a router only and now it does and my airport acts as the router to my network.  also thanks for the tip on typing "home" to get to the gateway settings.   

Message 8 of 8
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