Funny NTL 200 DHCP problem

[damanc]

First of all, Hi! I have been a CF lurker for a while now but have not needed to sign up until today.

I have a VM engineer due to visit tomorrow but wondered if you guys can shed any light on the problem. I have been in the trade 10 years now and have never seen anything like it, althou to be fair, the only Cable connection I have anything to do with is my current faulty one!

The problem started the night before last. Internet connection droped and my Linksys wrt54GL flashed with tomato was unable to obtain a WAN address from the NTL 200 Modem. Anoyingly enough It wasnt able to gain an address when it was reset/shutdown or used with no less than 5 different network cables. Firmware reset didnt solve the problem either. Out came the old router that was working fine a couple of weeks ago to no avail, as too a couple more cable modems which are brand new, guess what? Same problem.

Ok so what happens if I plug my modem directly into one of my machines. It works! a valid local DHCP address is assigned and I have internet access. So I tried another machine, this time it failed. I was getting 169 assigned address's. Up comes the next PC which was also a fail. Finally a laptop which worked straight away and then since I had it first working, its since gone down the road of 169 address's. Strange......

I spoke many a hour on the phone to VM last night, we were simply going over old ground as well as explaining that my 4 PC's and 4 Routers were up the spout. Yeah ok then ;) The best bit was when they explained to get my routers and PC's checked out by a local I.T. company. I took great pleasure in explaining to them I am an I.T. Support company. :D

I continued having a Play and noticed that the modem would give a directly connected PC an address with the COAX cable unplugged from the modem. Once I had the address I simply screwed in the COAX cable, it sync'ed and there was the internet. This worked on all the PC's that were unable to get an address in the first place and on my orginal router.

VM are now aware of this and have finally agreed to pay an interest to my support call with, as mentioned earlier, a engineer due on site tomorrow.

My question is to know if this is a common fault and to shed any background knowledge, if there is any?

Thanks

[whydoIneedatech]

First of all, Hi! I have been a CF lurker for a while now but have not needed to sign up until today.

I have a VM engineer due to visit tomorrow but wondered if you guys can shed any light on the problem. I have been in the trade 10 years now and have never seen anything like it, althou to be fair, the only Cable connection I have anything to do with is my current faulty one!

The problem started the night before last. Internet connection droped and my Linksys wrt54GL flashed with tomato was unable to obtain a WAN address from the NTL 200 Modem. Anoyingly enough It wasnt able to gain an address when it was reset/shutdown or used with no less than 5 different network cables. Firmware reset didnt solve the problem either. Out came the old router that was working fine a couple of weeks ago to no avail, as too a couple more cable modems which are brand new, guess what? Same problem.

Ok so what happens if I plug my modem directly into one of my machines. It works! a valid local DHCP address is assigned and I have internet access. So I tried another machine, this time it failed. I was getting 169 assigned address's. Up comes the next PC which was also a fail. Finally a laptop which worked straight away and then since I had it first working, its since gone down the road of 169 address's. Strange......

I spoke many a hour on the phone to VM last night, we were simply going over old ground as well as explaining that my 4 PC's and 4 Routers were up the spout. Yeah ok then ;) The best bit was when they explained to get my routers and PC's checked out by a local I.T. company. I took great pleasure in explaining to them I am an I.T. Support company. :D

I continued having a Play and noticed that the modem would give a directly connected PC an address with the COAX cable unplugged from the modem. Once I had the address I simply screwed in the COAX cable, it sync'ed and there was the internet. This worked on all the PC's that were unable to get an address in the first place and on my orginal router.

VM are now aware of this and have finally agreed to pay an interest to my support call with, as mentioned earlier, a engineer due on site tomorrow.

My question is to know if this is a common fault and to shed any background knowledge, if there is any?

Thanks

Soundslike the modem has a fault, explain to the engineer as above and he should replace your modem.

[mikey]

Sounds to me like the network DHCP has a dislike for a multitude of MACs connected to it.
Try cloning the MAC from the PC that works, on to the router. This may work.

[whydoIneedatech]

I have just re-read your post, you say you have 4 PCs and a router that is 5 separate MAC addresses, and you have tried connecting other devices also to the internet as well, the Host Table on the UBR can only accept a Maximum of 5 devices per property, so your first 5 devices are probably registered on the UBR so no others can get onto the Host Table.
You need to call Tech Support and get their 2nd Line Techs to clear your Host Table and you may be back to normal.

[damanc]

Cheers for the pointers guys. The Engineer came out today and after repeating what I have already done, swapped the modem out. All is well :)

[mikey]

Nice 1.
But remember to keep in mind the comments about moving from one MAC to another or you will have the same problem.