Ok so this leads us further down the path that the issue was cached mac
addresses; so if you take the time to wait for the arp cache (what they call
it when you cache mac addresses) on the other end to timeout, then it'll
accept a new one...which actually means it's behaving as it should and that
the router probably isn't bad!
But to troubleshoot your router to make sure, we need to break it into the
two sides:
1) So you should be able to redo the test below (unplug the modem for 15-30
mins) and then plug the modem into the ROUTER, and then go to the router
(don't plug in any PCs btw) and check the WAN section, and make sure it's
getting an IP address, and note what this IP address is.
Btw, when you connected the game box directly to the cable modem, did you do
an ipconfig/all and note what IP address that was? It should be the same IP
(or very close to it) that your router gets now--even if you don't have a
static IP assigned by Comcast, they usually just give you the same one or
something close in that range...
2) You should test the LAN side separately; now w/o having the WAN port on
the router connected, plug all the PCs into the LAN ports on the router, and
make sure they're all getting DHCP addresses, and ones in the right range
(typically 192.168.1.x/24 or so). You should be able to do ipconfig/all on
each and see the IPs and then ping each PC from the other. If you can do
this, then DHCP on the LAN from the router is working fine, and your LAN
stuff is fine.
At that point if the above two tests work, your router should be fine, and
your problem all along was that somehow they were looking for the wrong mac
(step 1) on the public side, and powering down the modem and letting the arp
cache timeout and then reconnecting with the modem should get everything
working again (again check the WAN section and verify you're getting a IP
there through DHCP and it's not timing out like before).
The router *might* be dead, but it's not likely...let us know what you find
out!
BINO
P.S. Hmm, something that occurred to me just now; there might also be a
checkbox or something to NAT the LAN network which you might have to
select...I can't find it on my router (Belkin) but I thought I remembered
seeing it somewhere (maybe it was a Linksys). Hunt around for that, as that
might explain why only one PC can connect through the router but not others;
this is a long shot, but hey, you never know! :P
P.P.S. Also, you should try upgrading your firmware to the latest. Another
thing that might not hurt is to reset to factory default settings on the
router.
P.P.P.S. Final thing you can do is to try and use the router as a switch (as
you suggested). If the cable modem can do DHCP, just plug it into a LAN
port on the router and then plug the rest of the PCs in, and then do a
"ipconfig /release" then "ipconfig /renew" on each of them from the cmd
line. Then "ipconfig /all" to see if they have an IP from the cable modem
(since you said the picture shows it with a hub/switch). What happens then?
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Stan Zaske
Sent: Monday, January 26, 2009 8:24 AM
To: [email protected]
Subject: Re: [H] Comcast blues
I unplugged my modem for 1/2 hour or so and plugged it back into my game
box and it connected but then would not connect to the others. This
leads me to believe that my router has gone bad. Thanks for the help folks.
Bino Gopal wrote:
> Hmm, interesting. So remember there are two sides, like you said WAN and
> LAN.
>
> WAN refers to the side b/w Comcast and you; to you that's the "WAN" side.
> You cable modem is the device getting an IP from the headend/CO and then
> giving it to whatever device you plug it into, in this case your router.
So
> on your router's WAN port, it's configured for DHCP so it should just be
> able to do DHCP to the cable modem and get it's IP if everything is
working
> properly.
>
> But it sounds like there's some issue b/c when you try to renew the IP on
> the router, it's not getting the proper DHCP response...but if that other
PC
> is working...hmmm...
>
> So current theory (w/o seeing it/more info): yeah, somehow the cable modem
> has the mac of the PC cached and that's why your router is not getting an
IP
> and only that PC is. As Bryan suggested, unplug everything and leave it
> unplugged for 15-30 mins and then plug the cable modem back in and the
> router to the cable modem and check the WAN status on the router and see
if
> it can get a public IP or not...that should be the first troubleshooting
> step...
>
> BINO
>
>
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Stan Zaske
> Sent: Sunday, January 25, 2009 11:35 AM
> To: [email protected]
> Subject: Re: [H] Comcast blues
>
> Under my router's Device Info, the status tab has a LAN section on top
> and a WAN section underneath. The WAN section lists mack address,
> connection, IP address, subnet mask, default gateway, and lastly DNS. To
> the right of connection it says: "DHCP Client Disconnected" and to the
> right of that are two buttons for DHCP release and DHCP renew. I've
> tried the release and renew buttons but the renew action goes to a
> screen that says "renew IP timeout". I'm pretty sure that this is the
> reason none of my boxes will connect through the router to the Internet.
> Am I missing something or can anybody add anything? Thanks!
>
>
> Bryan Seitz wrote:
>
>> Usually you can wait ~15 minutes and it will time out as well with the
>>
> cable
>
>> modem powered off/unplugged.
>>
>> On Sun, Jan 25, 2009 at 09:19:14AM -0800, John R Steinbruner wrote:
>>
>>
>>> Not sure about there, but here, they keep track of the mac address.
>>> When I changed from an old 10 base T router to a brand new G Wireless
>>> router at a rental place once, I had to change the Mac address of the
>>> new router to match that of the old one before anything would work..
>>>
>>>
>>> On Jan 24, 2009, at 6:50 PM, Stan Zaske wrote:
>>>
>>>
>>>
>>>> Have any of you ever run into a situation where your router's WAN port
>>>> seems to stop working but your ethernet connections among 4 PC's are
>>>> fine? Then after some more investigation it seems that your cable modem
>>>> will only connect one PC to the web and none of the others? The only
>>>> thing I can figure is that my router is fine but Comcast has locked
>>>> (possibly) my service to the MAC address of this one box and will only
>>>> connect to it but none of the others. Is my thinking straight on this
>>>> or can any of you come up with an alternate scenario? It seems might
>>>> strange to me that I can take the ethernet cable from my Mororola cable
>>>> modem and switch it from one box to another and only the one will
>>>> connect. What the heck is going on?
>>>>
>>>>
>>>>
>>>>
>>> --
>>> JRS steinie**[email protected]
>>> Please remove **X** to reply...
>>>
>>> Facts do not cease to exist just
>>> because they are ignored.
>>>
>>>
>>
>>
>
>
>
>
