[Thorin]

I setup my Linksys WRT54G through its web based interface and after I had done that I shut it off, plugged in my cable modem, powered the CM on, then powered the router on. I'm connected wirelessly to the router, and have internet connection. The router is set up to use DHCP, and my IP address should be 192.168.1.100 as my laptop is the only computer attached to the router. Instead my laptop's IP address is the same as my Cable Modem's external IP address.

It's like my laptop is somehow bypassing the DHCP server on the router and is instead getting its IP address from NTL's (NTL being my cable co) DHCP server. This isn't a problem I've encountered before, I've no idea why it's happening, and I can't get into the router's web based config screen anymore. When I try to go to 192.168.1.1 I get a server not found message, presumably because it's looking for that IP address on the internet, rather than on my local network.

Even weirder, if I go into sharing in System Preferences, the "other Mac users can access your computer at" address it gives at the bottom for Personal File Sharing is a hostname relating to my ISP. If I go into Terminal, rather than having my computer name, and my username before the prompt, I have the hostname from my ISP.

It's as if my mac is bypassing my router, and just connecting straight to my ISPs network, but I've no idea how it's doing it, or how I can stop it.

Now the first time this happened I ended up shutting off the router, unplugging everything, and resetting it to factory settings. Problem was when I powered it back on it wasn't broadcasting its SSID, and I couldn't connect to it by plugging in with ethernet either. That's when I posted my thread about buying a replacement for it. Thing is I left it unplugged, tried it the next day, it worked fine, but once I set it up I encountered the exact same problem again.

To register the cable modem with my ISP I had to connect the cable modem directly to my Mac and run some software. The only thing I can think is that the software's somehow making my mac behave like this, but I don't know what it'll have changed or how to change it back.

This is using a 12" rev B Powerbook running 10.4.2

[ghporter]

Your router has the capability to report its MAC address (that's the hardware address of its WAN-side network connection) as ANYTHING you want it to report. So put your Mac's MAC address (you can get this from Network Preferences-select the Built In Ethernet device to see it) into the router and see if the router can connect to the modem. I think it will. (The MAC address options show up in different places depending on the firmware version-look through the router's manual to find the exact place for you.)

A while back cable providers in the US stopped (for the most part) limiting users to a single device connected to their modem-this was enforced by having the cable modem check the MAC address of whatever was connected to them. I guess they gave up because they couldn't block use of routers that would report any MAC address the user wanted. This is the first I've heard of a UK cable provider being interested in the MAC address of what's connected to the modem...

[Thorin]

I've had cable with the same provider for about 4 years, using the same router. 4 weeks ago I moved out of my previous house, and a week ago into my new house. When they installed cable this time they gave me a newer modem, and I've had the problem since then.

I'll try the MAC address clone and let you know.

[Thorin]

I've cloned the MAC address, but I still have the same problem.

I have internet fine, but the IP address I'm being given is an external address, not an internal LAN address from the router. Any other ideas?

[Thorin]

I'm wondering if this could be being caused by a faulty WRT54G? As my wireless signal's just vanished, even though all the lights are still on at the front of the router. I've tried powering it down and back up again and all the appropriate lights come on, but no wireless network. It's just annoying that I don't have access to another router so I can see if that's the problem!

[tooki]

Honestly, based on the first post, my best guess is that the cable modem is plugged into one of the router's LAN ports, rather than the WAN port.

tooki

[Thorin]

Appreciate the suggestion tooki (and I'm the first to suggest simple obvious things when trying to assist other people), but that's not the problem. The cable modem's been in the 'Internet' port every time.

As before, after leaving the router for a while the wireless signal has returned, and I can connect to it again.

I really am starting to think it's just faulty router, but I'll be seething if I buy a new router and still have the same problem. Thanks for the help so far guys, any further suggestions greatly appreciated.

[Big Mac]

I think you're right, Thorin - it sounds like your router's malfunctioning. If your hostname is getting changed to an ISP address, that certainly indicates that the computer is getting its address directly from the ISP. Routers don't last forever. You may want to consider a different brand, btw - I'll always recommend against Linksys unless and until they acknowledge the Mac.

[Thorin]

Originally Posted by Big Mac

I think you're right, Thorin - it sounds like your router's malfunctioning. If your hostname is getting changed to an ISP address, that certainly indicates that the computer is getting its address directly from the ISP. Routers don't last forever. You may want to consider a different brand, btw - I'll always recommend against Linksys unless and until they acknowledge the Mac.

Looks like it's time to go router shopping then. What would your recommendation be then? I did post in here asking for suggestions for WRT54G replacements before when I couldn't get it working at all!

[ghporter]

To replace a WRT54G that you've been happy with, I'd say go for a WRT54GS. It has more RAM and ROM so it can handle more traffic throughput, and bigger third party firmwares (which can give you some "interesting" new configuration choices). And they're coming down in price all the time.

The problem is that I can figure about a dozen ways for the router portion of your router to fail and stop all traffic, but only ONE way it could give you straight-through traffic; have you gone through the configuration and made sure your computer isn't set up in a DMZ or something?

[tooki]

OK, well if it's all plugged in right, I have one other suggestion: In the "Advanced Routing" tab of Setup in the router, what is the Operating Mode set to? It should be set to "gateway".

tooki

[Thorin]

Again, thanks for all the help peeps.

It is set to Gateway, and the DMZ setting is disabled .

Can I just confirm that nobody thinks this is likely to be being caused by changes the ISP software made to my laptop?

Thanks for the WRT54GS recommendation ghporter .

[ghporter]

Woah! I didn't see anything about ISP software... Please give details! It's quite possible that their software DID do something to your laptop that keeps it from getting an IP from the router.

[budster101]

Unplug the router, modem etc...

Plug the computer directly back into the modem, and then turn them both on again.
Get the IP, and now go through the procedure of connecting the router.

Everything in your settings should be set to automatic.
Also, there should be no software on your computer from the ISP. It isn't necessary. None.
Whoever set your system up had no clue.

[Thorin]

I set my system up! I couldn't register my new cable account without running their software.

ghporter, I've described the ISP software in the original post. In the last paragraph.

I've found a log file from the setup software (which I really did not want to run on my Mac, but I had to to register my account with my ISP), here it is with anything too sensitive edited out:

Code:
[VirtualTruck]
MainAppVersion=1.8.4d4
VTID=501377
trail=1,37,38,88,89,55,56,39,40,41,42,43,44,45,46,71,72,53,54,0
trail_times=4,10,14,16,17,2106,2106,2106,2111,2111,2122,2122,2122,2122,2122,2122,2122,2122,2146,2146
num_executions=2
trail_history=1,37,38,88,89,55,56,39,40,41,42,43,44,45,11,11,1,37,38,88,89,55,56,39,40,41,42,43,44,45,46,71,72,53,54,0
trail_times_history=4,159,169,198,232,461,461,461,476,476,500,500,501,501,511,555,1878,1884,1889,1890,1891,3981,3981,3981,3985,3986,3996,3996,3997,3997,3997,3997,3997,3997,4020,4020

[ImportantTimes]
BeginSetup=09/20/2005 09:54:09

[OperatingSystem]
OsType=Mac OS
Version=10.4.2

[RAM]
NumMegs=512

[HardDriveSpace]
VolumeName=Int HD
DriveSize=76311 MB
DriveFreeSpace=24668 MB

[Drives]
has_floppy=0
has_cdrom=1

[NIC]
MacAddress=[my NIC's MAC address]
DHCPEnabled=1
IPAddress=0.0.0.0
SubnetMask=0.0.0.0
DefaultGateway=0.0.0.0
DNSEnabled=0
Domain=

[CPU]
num=1
speed=999
family=274
product_name=

[USB]
present=1

[CustomUserInput]
CustomScreen0_PIN:=[my broadband PIN]

[UserInput]
techid=Self Install
FirstName=Graeme
LastName=Shaw

[EmailConfiguration]
display_name=Graeme Shaw
pop_server=pop.ntlworld.com
smtp_server=smtp.ntlworld.com
email_address=[my email address]
email_domain=ntlworld.com
num_new_email_accounts=1
email_address0=[my email address]
display_name0=Graeme Shaw

[NewsConfiguration]
server=news.cable.ntlworld.com
user_name=[my username]
username0=[my username]

[WebBrowserConfiguration]
default_web_page=www.ntlworld.com/broadband/broadband.htm

[InternetConnectionTestResults]
num_ping_tests=2
default_gateway=81.111.68.254
gateway_ping=100
ping_server0=62.253.162.237
ping_test_result0=100
ping_server1=216.142.26.253
ping_test_result1=100
num_dns_tests=1
dns_test_result0=passed
domain_name0=cache1.ntli.net
num_dns_strict=0
num_tcpip_tests=1
tcpip_server0=pop.ntlworld.com
tcpip_port0=110
tcpip_test_result0=passed

[LoginInfo]
Username=[my username]

[DownloadClientInstaller]
Installer_Source=local

[GoldenKeys]
domain=ntlworld.com

Does "domain=ntlworld.com" mean the setup software has added me to the ntlworld.com domain? How would I change that?

Budster: that's exactly what I've done both times I've tried to set this up, the outcome is described above. As far as I can tell there is no software remaining on my computer from the ISP setup, but looking at the log it does look like it's changed some of my system settings.

[ghporter]

Thorin, I missed that in my original read. Sorry, because I think what's going on has a lot to do with what the software did. From the log it looks like it did a number of things, particularly setting your browser's home page, and establishing a lot of email settings.

What I think is happening is that your WRT56G now needs to have a new setting: it needs to know it's part of the provider's domain. On the first page of the router's setup there's a set of boxes that let you set the router's name (default is WRT54G) and such. The third box is for the domain name-you should put "ntlworld.com" in that box. (You should also make sure the MTU is set to automatic if it isn't already.) Of course your user name and password should go in the appropriate boxes as well, as it seems this cable provider does some sort of authentication.

[Thorin]

Before I moved house I didn't have any of those settings in (though I will try as you've suggested). I knew it set up an email account in mail, which I've left because it's actually useful, and it changed Safari's homepage, but I just changed that back to my normal homepage.

I'm in the middle of something at the moment, but I'll try your suggestion later this evening (UK time) and let you know how it turns out.

Again, thanks for all the help and suggestions folks.

[Thorin]

Just to clarify, things like my 'broadband PIN' were just used to match my account/billing details to this installation, it's not stored anywhere on my computer in any settings. I really don't think my laptop is authenticating onto the NTL network all the time. If anything I think I need to remove my laptop from the NTL domain rather than add the router.

As I said though I will try your suggestions.

[budster101]

Never let the cable guy touch your mac. They only lay cable.. most don't know anything about setting up a mac.

[Thorin]

Fixed it.

I'd tried it with another powerbook, and encountered the same problem. Whichever book connected first got the external IP address from the router, the next to connect got a router assigned IP address, but had no internet access. A new WRT54GS came this morning and it worked straight away, so it looks like my WRT54G had developed some strange fault.

Thanks to everyone who gave advice and suggestions.

[ghporter]

Stuff breaks, wears out and dies. This is life. Getting the stuff replaced and having it work right away is cool. Congrats!

[Thorin]

The WRT54G had been on 24/7 for over two years, then had been unplugged, stuffed in a box and stuck in a garage for a month. The last piece of networking kit to break on me was an intel 8 port switch that worked fine for two years until one day it was unplugged and just wouldn't fire back up again. Don't unplug stuff!

Was a relief that the WRT54GS worked straight out of the box though, as I still wasn't certain that the other router was the problem.

[John Strung]

I think you have to use the MAC address cloning feature of the LinkSys to clone the MAC address of your PB.

When you first connect your PB to the modem and ran the setup software, it probably recorded the MAC address (also known as the hardware address or the internet address) of your PB. The MAC address is a 12 character hex number, something like 00:0A:AB:6F:5E:FF using numbers 0 to 9 and letters A to F. Thereafter, the modem won't connect to any device with a different MAC address.

The Linksys, somewhere in its web based administrative utility, has the ability to "spoof" you Mac's MAC address. Get the MAC address from your PB and enter it into the appropriate box in you LinkSys and you should be back in business.

[John Strung]

I think you have to use the MAC address cloning feature of the LinkSys to clone the MAC address of your PB.

When you first connect your PB to the modem and ran the setup software, it probably recorded the MAC address (also known as the hardware address or the internet address) of your PB. The MAC address is a 12 character hex number, something like 00:0A:AB:6F:5E:FF using numbers 0 to 9 and letters A to F. Thereafter, the modem won't connect to any device with a different MAC address.

The Linksys, somewhere in its web based administrative utility, has the ability to "spoof" you Mac's MAC address. Get the MAC address from your PB and enter it into the appropriate box in your LinkSys and you should be back in business.

[Thorin]

Yeah I'd already tried MAC address cloning. I also went away for a week and left both the router and the modem switched off, which should have cured that problem were that the case. It didn't.

The new router worked straight out of the box without MAC address cloning, so I don't think that was the problem. Pretty certain it's just a router in its death throes now, but thanks for the suggestion.

[John Strung]

Have you tried updating the router firmware? If the old firmware is corrupted, that might solve the problem.