MalibuCH
join:2007-09-08
Malibu, CA
| [HSI] AirPort Can't Get Legit IP Address From Charter Cable Mode
I am having a perplexing problem.
Neither of my two AirPorts can coax a legit IP address from Charter, making it impossible for me to access the internet wirelessly.
My network works fine between computers (I have 4 Macs). The modem is fine...I can get an legit IP address when connecting via ethernet.
But, Charter will not hand over an working IP address to my AirPort. I tried manually putting in the IP addresses I got when working via ethernet, but that didn't work.
I've worked it all out and narrowed it down...Charter won't talk to my AirPort about IP. 
Any ideas? |
|
MrFixit1
join:1999-11-26
Madison, WI | Re: [HSI] AirPort Can't Get Legit IP Address From Charter Cable
Just a few questions
1 Are you trying to pull more than 1 IP at a time ?
2 Just how are the AirPorts hooked up ( what to what )?
3 Is there a router in the picture ? |
|
MalibuCH
join:2007-09-08
Malibu, CA | 1. No. I just need one working IP address. The AirPort redirects the stream.
2. The AirPort (I only use one at a time) is plugged into the modem via ethernet.
3. No. The AirPort works as the router.
Thanks! |
|
GGrotyohann
Premium
join:2002-02-17
Kitty Hawk, NC | Are you power cycling the modem before connecting the Airport? Is the Airport set for DHCP on the WAN port?
Greg |
|
MalibuCH
join:2007-09-08
Malibu, CA
| Well, I had done it many times, but I tried it yet again at your suggestion.
And, it worked! 
I have no idea why it wasn't grabbing a good IP before, but it did this time.
Thanks so much. |
|
chtr
@charter.com | reply to MalibuCH
Try a crossover cable between the modem and airport, or a straight on if you are already using a crossover. |
|
InnerMe
join:2002-08-30
| reply to MalibuCH
Actually Airports do some goofy stuff when they request DHCP. I believe it's a bug in the DHCP client they run, they will decline the DHCP offer infinitively (or until the scope runs out). Not sure what triggers it to happen but I've seen and documented it about 15 times now. |
|
MalibuCH
join:2007-09-08
Malibu, CA | Is there anything to "de-trigger" it?
As you can imagine, it was driving me nuts! |
|
InnerMe
join:2002-08-30
1 edit | reply to MalibuCH
Check for a firmware upgrade? In all the times I've experienced it the DHCP server is handing out the offer, and the Airport is declining it. In a standard DHCP transaction that would result in the DHCP server marking that lease as temporarily unavailable.
What I *THINK* it might be doing (and causing the trigger) is something like this.
Airport initially pulls a DHCP lease from DHCP server and everything is happy. Sometime later some type of communication error occurs that causes the lease to expire. (Modem drops offline due to RF, outage, stand by button is pressed, etc). When communication is restored the Airport should realize that it's lease is expired and request a new one but what it does it says 'No I still have x.x.x.x' and declines all the offers from the DHCP server that says otherwise. You might be able to force it re-learn by powercycling the airport for a couple minutes and unplugging the ethernet cable from it's wan port. |
|
daMacDaddy
@mindspring.com
| reply to MalibuCH
It seems Charter Cable service is not recognizing or giving an legit IP address to airport base station. It just started acting up 3 weeks ago.
Here is the work around.
1. hook up cable modem to ethernet switch box with just one Mac/PC connected.
2. Power Cycle modem, boot up the computer; you will get an IP address.
3. enable Internet sharing on your Mac/PC via whatever the ethernet port you have cable connected to (eg. ethernet 1 on Mac)
4. configure airport base station to be "bridge mode".
5. hook up airport base station to the ethernet switch box
Now it works!!!!!
h_h |
|
