Problem with DHCP on linux with NTL STB

[prop90]

Hi all,

I've been recently upgraded to NTL 2Mb Broadband ( from 512k). I've a machine with Windows/Linux dual boot setup. When I had 512k, both windows and linux used to work perfectly. After the upgrade I can only connect using Windows.

On Linux, I've set up the connection to be DHCP and the DHCP server to 10.185.6.139 (which I got from Windows). All I'm getting is time-out errors by dhclient (Mandrake 10.1). Is there any extra setting I need to be aware of on the NTL STB. Any help is greatly appreciated.

cheers

PS: I dont have any router in between. It is a straight connection from STB to PC.
PPS: I've originally posted this thread on NTL forum as this problem is specific to NTL and the good moderator there locked it! I can see the moderators are busy, but if they take a minute to read the content before locking threads, that would be very helpful.

[Paul K]

Originally Posted by prop90

Hi all,

I've been recently upgraded to NTL 2Mb Broadband ( from 512k). I've a machine with Windows/Linux dual boot setup. When I had 512k, both windows and linux used to work perfectly. After the upgrade I can only connect using Windows.

On Linux, I've set up the connection to be DHCP and the DHCP server to 10.185.6.139 (which I got from Windows). All I'm getting is time-out errors by dhclient (Mandrake 10.1). Is there any extra setting I need to be aware of on the NTL STB. Any help is greatly appreciated.

cheers

PS: I dont have any router in between. It is a straight connection from STB to PC.
PPS: I've originally posted this thread on NTL forum as this problem is specific to NTL and the good moderator there locked it! I can see the moderators are busy, but if they take a minute to read the content before locking threads, that would be very helpful.

Sorry The thread was locked as it's a setup issue and not an NTL issue, personally I would have prefered it if the thread had been moved here but it wasn't. I'll go grab a link to the thread so people can read the full story so far and not go over things you have already tried.
Ok the original thread was here
http://www.cableforum.co.uk/board/sh...ad.php?t=32512

[prop90]

Originally Posted by Paul

Sorry The thread was locked as it's a setup issue and not an NTL issue, personally I would have prefered it if the thread had been moved here but it wasn't. I'll go grab a link to the thread so people can read the full story so far and not go over things you have already tried.
Ok the original thread was here
http://www.cableforum.co.uk/board/sh...ad.php?t=32512

Thanks for that Paul. Much appreciated.

cheers

[Paul K]

I take it this information matches the information you get when in windows. From your post on the thread

Thanks for quick reply. The address I've given above is the NTL's DHCP server's address. Here are the full details from windows.

WINS Proxy Enabled IP Address. . . . . . . . . . . . : 80.2.188.xxx
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 80.2.188.1
DHCP Server . . . . . . . . . . . : 10.185.6.139
DNS Servers . . . . . . . . . . . : 194.168.4.100
194.168.8.100
Lease Obtained. . . . . . . . . . : 26 July 2005 17:04:09
Lease Expires . . . . . . . . . . : 05 August 2005 07:50:13
I've tried restarting STB and also the PC.

So the last post before closure was

Is that IP address automatically assigned or manually set? Was the STB changed out during the upgrade or are you still using the original one?
Have you tried pinging an address or IP address at all to see if you have any connection at all through the STB?

[prop90]

Originally Posted by Paul

Is that IP address automatically assigned or manually set? Was the STB changed out during the upgrade or are you still using the original one?
Have you tried pinging an address or IP address at all to see if you have any connection at all through the STB?

Oh yes! I typed the reply and lost it..which is why I was a bit irked.

Yes. The detials are from windows. The IP address is automatically assigned. Yes, the STB was changed during the upgrade. I tried pinging couple of IP addresses including DNS servers, but invain. In Linux, the PC is not getting an IP address at all. Log shows a 'time-out' error from dhclient (which negotiates with DHCP server for an IP address). I'm just wondering if NTL's DHCP server is Windows only or something like that.

thanks.

[Paul K]

In linux does it store the settings? Your set-top box has been changed so the IP address has changed. Did you have to re-provision or re-register the STB against your account?
Have you tried transfering the connection details that Windows is working with into Linux?

[jaycee]

Which dhcp client are you using with linux ?

You should not be giving DHCP *any* IP details, certainly not the IP of the DHCP server. This should be automatically discovered by the DHCP protocol, and manually assigning it will cause trouble.

edit: I have a feeling Mandrake will be using the "pump" dhcp client. Apparently, this is rubbish. I would look into using dhcpcd or dhclient, both of which work perfectly with NTL.

WINS proxy is unneccesary - this is a Windows file sharing thing. As such your Linux box will ignore it.

edit 2: i should read before posting, you are using dhclient. Check ports 67 and 68 are allowed through your firewall. I use dhclient on FreeBSD and it works perfectly with my NTL setup (I am using a cable modem, but it makes no difference)

edit 3: are you aware you have to cold boot the STB every time you change the NIC it is connected to ? It's possible the STB is simply ignoring the Linux box because of this.

[prop90]

Jaycee,

Originally Posted by jaycee

edit 2: i should read before posting, you are using dhclient. Check ports 67 and 68 are allowed through your firewall. I use dhclient on FreeBSD and it works perfectly with my NTL setup (I am using a cable modem, but it makes no difference)

I've not started the firewall (shorewall) yet as I cant make a connection with Linux. However, I've checked with 'iptables -L' to make sure no traffic is blocked.

Originally Posted by jaycee

edit 3: are you aware you have to cold boot the STB every time you change the NIC it is connected to ? It's possible the STB is simply ignoring the Linux box because of this.

It is the same NIC I'm using with both Linux & Windows. I believe the MAC address would be same irrespective of which OS I'm using?

Here's something I did trying to outsmart the NTL's dhcp server.
1. Boot into windows and get a lease.
2. Re-boot into linux and set the same config manually (giving same IP address etc.)

still the damn thing doesnt work.
I can see network packets going out but nothing coming back when dhclient is negotiating.

[jaycee]

This would point to it being a problem with the NIC driver on Linux. What kind of NIC is it and what driver is it using?

Try forcing a duplex setting instead of allowing auto negotiation. 10mbit half duplex should work. My guess is the old PACE box allowed successful auto negotiation, but for some reason the new Samsung one does not seem to work correctly with the Linux driver.

The NTL DHCP server will have assigned you a lease for 24 hours, when you shut down windows this lease would still be kept, so if manually assigning the IP you got to your NIC in Linux doesn't work, the problem is with the NIC in Linux. Also be aware that you would have to set the default route to the default gateway IP, as well as the NIC's IP to the leased IP. I dont know if it's the same for linux as freebsd but this means typing "route add default <default gateway ip>" at a shell. You'd also have to add the DNS servers to /etc/resolv.conf (you can safely do this - they won't change - dhclient may have already written them there anyway)

[BBKing]

I'm just wondering if NTL's DHCP server is Windows only or something like that.

Nope, it's Solaris and run by guys who are pure Unix geeks, trust me on this!

I've used dhclient on Debian (and FreeBSD) to connect to STB broadband in the testlab with no problem (via a Pace box). If your box is a Samsung (presumably, as it is 2Mb) it does help to force the interface to 10Mb/half duplex (this is the most conservative setting and well capable of 2Mb/s traffic. One thing you rapidly learn in networking is that autonegotation is no substitute for knowing what you're doing.

P.S.
It's
route add default gw <gateway>
isn't it? I have to switch between Solaris and Linux at work all the time and it always throws me how different the syntax is! In this case the gateway is 80.2.188.1, presuming you get your usual 80.2.188.x address.

[prop90]

Finally managed to solve this problem. As Jaycee mentioned, I had to change the network card settings to use 10Mbps/half duplex mode. This is done by using 'ethtool' available on linux. The command I used is
ethtool -s eth0 speed 10 duplex half autoneg off

It's working perfectly since then. Many thanks to Paul, Jaycee and BBKing.

cheers
prop90.