Cable modem (co-ax) and wireless router problem, PLEASE HELP!

[FuerteStuart]

Hello all, and thanks in advance!

Im pretty good normally with PCs and networking, but im :bang head and :mad: and :confused:
I am living in a UK house that has a cable broadband modem plugged directly into PC via ethernet. its an old PC and slow, and I have a laptop and 2 other PCs dotted around the house that are way newer and better. I also have an old ADSL wireless router not doing anything so i thought i would connect the cable modem up to the router and try and get the other 2 PCs and laptop onto a wireless connection!

Not so simple, the cable modem wont let me do anything with it. Ive played around a bit but cant get anything going really. HELP:bang head

Ideally i would like this setup here...

http://img254.imageshack.us/img254/5186/setupgt4.png (http://imageshack.us)

The Wireless Router is an ADSL router but I could get it working as an AP couldnt I?
The old PC is slow and isnt on all the time. but i still need it net connected for the MIL (mother in law).
The other 2 PCs and the Laptop were running great on wireless in the last place I was in, but that was ADSL straight into a phone line. PLEASE, i though it would be quite simple just to tell the router to look to the cable modem for its connection, but i am really, REALLY struggling!!!!!!!!!!!!


:santa2: Thanks all:beer:

[FuerteStuart]

P.S.

The ADSL router is a ZyXEL P660HW-D1
The Cable Modem is a Scientific Atlanta EPC2100
The Cable Provider is Virgin Media
My shoe size is 9 (uk)

[ppe1700]

hi! i have friends who live in tenerife, christmas there one year was really good..

anyway,
the thing about cable modems, is that they will only issue one IP address. and the thing about adsl routers is that they will only request an ip address on its ADSL interface.

so, what you will need to do is go and buy the cheapest "Cable router" you can - you do not need a wireless ready one as you can use your adsl one for the wireless.

cable modem will have a ethernet port on its own (may be labelled as WAN) and this is for the cable modem, unplug it from your pc and plug it into here.
then plug your pc and anything else into the other "switch" ports and then they will all get IP addresses leased by the new router you just bought.

now if you want to add wireless, you will need to setup the ADSL router first, so that DHCP is turned OFF, and you have set up wireless security. once you have done that, then plug the adsl into the cable router.

if you run out of ports on the cable router, you can plug devices into the free ports on the adsl, and as long as its connected to the cable router it should work.
make sure that when you connect the two together, that the corresponding Light for that port on both devices Illuminates!
- if it does not illuminate, you will need to use a crossover cable.

one final note for when you first plug everything together - leave the cable modem turned off so that it 'forgets what it was plugged into last'
you might need to reboot the cable modem to get it to issue an ip address to the new router, but once its setup you wont have to do that again.

nice drawing :)

[ppe1700]

P.S.

The ADSL router is a ZyXEL P660HW-D1
The Cable Modem is a Scientific Atlanta EPC2100
The Cable Provider is Virgin Media
My shoe size is 9 (uk)

thats absolutely terrible








size 9? :santa::beer::)

[FuerteStuart]

Hello, thanks for your reply.
Ive just moved back from Fuerteventura. Now in sunny ol UK.

had it all plugged in and was overcomplicating the whole thing... didnt try a reboot of all involved. just having the issue now of the wireless router not enabling by default, but dont know its IP to enable it as it has now changed!!

[ppe1700]

virgin wont issue you ip's so, virgin will see the mac address of the pc it issued previous as you have it all plugged up, and then that pc will get its ip again and work.
nothing else will though.

do a factory reset on the adsl router and look at the instructions.

the way you have it plugged up wont work. trust me, ive tried it.

fuertaventura - nice place. black sand and everything. :)

[FuerteStuart]

OK, ive got the old PC working fine, and enabled the WLAN on the ADSL router (ZyXEL), The laptop will now connect to the WLAN and gets 5 bars signal, but no net.

Its connecting fine, but I think that the ZyXEL is not forwarding from Wireless to thehardline connection any ideas???


Fuerteventura... nice place to visit, I lived there 5 years. Great friends, but glad I left.
Tourism has been killed off by incompetance in government, and the bad exchange rate. mostly a ghost island now, shame

[bz2klag]

Unless the ADSL router has a WAN side ethernet port you can plug the cable
modem into, it isn't going to work, or be a practical solution for connecting
multiple PCs to the internet, no matter how it's configured. You might be able
to use the ADSL router as an AP, but only if you can turn off its NAT and
DHCP server functions.

Sorry, it has do with WAN side ethernet ports and LAN side ethernet ports
being treated differently by a router (any router), and most ADSL routers
don't have a WAN side ethernet port exposed, as the DSL modem is already
built-in.

[FuerteStuart]

Unless the ADSL router has a WAN side ethernet port you can plug the cable
modem into, it isn't going to work, or be a practical solution for connecting
multiple PCs to the internet, no matter how it's configured..
No WAN side Ethernet, just 4 ethernet ports and a WAN RJ11 socket.

Ive plugged the cable modem and old PC into the router and the old PC is connecting through to the internet fine, but i cant link the wireless through.

You might be able
to use the ADSL router as an AP, but only if you can turn off its NAT and
DHCP server functions.
This is what i was hoping to do (i think) from the pic posted in the first opst.

Ill try disabling NAT and DHCP and see what happens, post more tommorrow.

[gangaskan]

i think you will need a Ethernet router really.


some ISP's provision your computers MAC so you would need to clone it in order for this to work properly.

[FuerteStuart]

i think you will need a Ethernet router really.

OK, where would I need to put it on the network?
I would have thought that the ADSL router was acting as that?

heres a pic of the back of the router...
http://img377.imageshack.us/img377/7827/pic0002xl3.jpg (http://imageshack.us)
The PC works perfect, but wireless connections to the router are not passing through to the cable modem... :bang head

some ISP's provision your computers MAC so you would need to clone it in order for this to work properly
I will try connecting the laptop via ethernet and see if it surfs ok. That should tell either way

[FuerteStuart]

Laptop connects fine via ethernet, so it cant be mac address related.
I had to reboot the cable modem for it to aquire an IP address though..
and i only have 2 ethernet cables at the mo, so the pc wasnt on at the same time.
It might be im only being issued one IP address. Ill find out tommorrow when i get another cable.

Is there anyway to assign the ADSL that IP and use let all connect through that? either static DHCP or just static IPs??

Thanks all, I know im a pain in the arse ;-)

[FuerteStuart]

Im on virgin media, i have a wirless access point (non virgin, d link), and the cable modem is connected via ethernet cable into the wireless access point, works fine with wireless alround the house, had a bit of a problem when the access point and cable modem each wanted to use there own MAC addresses(conflict), ended up having to clone the cable modems MAC onto the wireless access point.

Just found this on another webiste... anyone know how to clone the mac address of the modem to the router? :-)

[bz2klag]

Yes, you can get 1 PC working, because your ISP gives you one ip address.

If you want multiple PCs on the internet, however, you will either need additional ip
addresses, or you need a NAT router, which allows multiple PCs to share the internet over 1 ip address. NAT routers treat communication from one LAN port to another LAN port differently than they treat communications moving from LAN to the internet.

Right now your ADSL router is basically just a LAN switching hub with no ability to provide NAT from one LAN port to another for the purpose of putting multiple PCs onto the internet with a single ip address. That is why this will never work. The ADSL router was never intended to be used in this way. Yes, you can use it as a LAN switch, but that's all it will ever be.

[gangaskan]

Yes, you can get 1 PC working, because your ISP gives you one ip address.

If you want multiple PCs on the internet, however, you will either need additional ip
addresses, or you need a NAT router, which allows multiple PCs to share the internet over 1 ip address. NAT routers treat communication from one LAN port to another LAN port differently than they treat communications moving from LAN to the internet.

Right now your ADSL router is basically just a LAN switching hub with no ability to provide NAT from one LAN port to another for the purpose of putting multiple PCs onto the internet with a single ip address. That is why this will never work. The ADSL router was never intended to be used in this way. Yes, you can use it as a LAN switch, but that's all it will ever be.



yup, thats it :) you have to have a dedicated WAN port and be NATTED

a clone of your orig mac wont be useful here, go and grab yourself a one with a WAN port

[FuerteStuart]

okey dokey...
Got one ordered on Ebay!

Thanks to all who have commented. I trust we all learned a little something.
Me more than anyone else ;-)

[normjr143]

We have netgear modem, the problem we are having is to many computers on the modem there is 6 computers on this wireless modem .what I wanted to know if there is a cable modem out there that will support that many computers? thanks

[I.M.O.G.]

norm,

You should start your own thread in this forum to be helped. By posting in someone elses thread about your problem, it is unlikely you will get the help you need. You can do so by clicking here:
http://www.ocforums.com/newthread.php?do=newthread&f=16