boomer

Anyone use Virgin broadband via a cable modem (and is reasonably techy)?

I am trying to understand how it is all configured (for a friend), and the supplied docs and web-site FAQ are pretty much useless

As far as i can tell, the "cable" goes into the modem and ethernet comes out. Booting a PC on the LAN side allocates a DHCP IP address with a subnet of something like 255.255.252.0, so the DHCP server must be up the cable somewhere.

So what if i boot a second PC, and a third etc.? Will Virgin keep offering me IP addresses, or does it somehow lock them down to a given modem (and how)?

I also tried adding a Wireless Access Point (which also acted as a hub), but although the wireless authentication worked, Windows had problems "acquiring an IP address" - so is there only one IP address per modem?

Beardies FAQ simply suggests...



mb

Tidgy

not quite sure what your trying to do?

i run mine from the modem to a router (wireless and cable), wired connection to my desktop pc and then wireless to my GF laptop.

are you trying to go through a router?

HHxx

That was how it all worked when I was on cable. 1 IP address per modem (1 per modem mac address)

You will need a router connected to the modem to perform NAT first before hitting you internal network.

+Doc+

Im no expert buy here goes.
This article may help: Router IP Address - How to Find a Router's IP Address
They will all share the same IP as they are all connected through the same modem.

So your modem is also a wireless router? If so then whatever hardware is trying to connect to it, be is a wii, a lappy or an xbox, the router will need setting up with a password, if it is an open router then anyone in close vicinity can steal your connection.
The hardware connecting to it will use wifi to connect and find yours and others around you automatically.

boomer

Basically, i want to be able to connect multiple computers (via hardwired Ethernet and wireless) to the Interweb through the Virgin cable connection. Not currently using a router, 'cos it is a modem (provided by Virgin) that provides the cable connectivity.

What kind of router do you use? If the modem outputs via Ethernet, then presumably your router must have two separate Ethernet "subnets" to separate LAN and WAN traffic?

Cheers,

mb

boomer

I think that you are correct - one IP address available "per modem", even though the address is allocated directly to the computer getting it's DHCP address over the "ethernet". Thus i will need something to do the NAT side of things - normally using a router, but as mentioned above, tricky to connect via Ethernet on both sides.

Cheers,

mb

HHxx

You just need a cable router which has an ethernet interface for its wan port or a firewall doing the routing etc. The cable router would do exactly what a adsl one does but with an ethernet interface.

boomer

Just connecting a computer to the Ethernet output of the modem and booting comes up with a proper DHCP IP address (including Default Gateway etc.) - as if Virgin was connected directly via Ethernet. I'll do a test tomorrow to see whether a second IP address is served when booting a second computer (although it seems unlikely according to HHxx).

The modem is just that, a cable modem - cable, power and (single) Ethernet connections only.

The Wireless Access Point i mentioned is actually an old ADSL Router (D-Link), but configured just to be a WAP (and yup, i have enabled WPA security). As it has a four-port Ethernet hub, it would be a convenient way of connecting three hardwired computers, and indeed it works for a single computer (but probably not for more that one, as only one IP address will be available from Virgin).

Looks like the sensible way forward is to replace the modem with a cable wireless router - why o why couldn't Virgin not simply provide one in the first place

Cheers,

mb

HHxx

One more thing. When/if you go for a router, the modem may not give an ip address to the router immediately as it has already leased one out to your pc etc. Either unrelease it before connecting up you new kit or you have to wait till the lease expires. Could be a day, shorter or longer dependant on what they chose to be the lease time.

In other countries, you can purchase your own cable router that accepts a coax connection, DOCSIS routers, over here Virgin control access/throttling etc via the modem and don't like people playing around

boomer

Aha,

it is starting to make sense now!!!

So a cable router is actually connected to the WAN via Ethernet and not (as i assumed) cable

Time to see if Virgin will come up with the goods, namely "You'll need a wireless router (we'll give you one for free*)."

Cheers,

mb

boomer

Good point about lease expiration, thanks for that

As for the modem controlling/throttling things, that would suggest that if you were to connect your own "vanilla" modem, you could have all kinds of fun

Cheers,

mb

phoenixgold

iTrader: (2)

Yep - you need a cable router. Different to an ADSL as you correctly state it will have an ethernet port for the WAN side. Your OP said that they would give you one free, so I would give them a call and ask. I had one FOC when they upgraded me to 50mb. They are only about £30 from ebuyer or similar.

As regards the lease issue, you just need to restart the cable modem after you have moved the ethernet cable to the router.

bigsinky

you get a free netgear cable router with the 50Mbit connection. i am currently running via router and gigabit switch between 10 and 12 devices of my cable connection.

warrenm2

As has been mentioned - virgin give a wireless router out foc. Connect from cable modem to wireless router (WAN port) with ethernet cable. Connect pcs/laptops to wireless router either via an ethernet cable (it has 4 ports on the back) or via wireless. The wireless router has its own DHCP server inside and handles ip address allocation

boomer

Well i managed to have a play before i got too bladdered last night, and now have the cable router configured and connected to the cable modem with WPA2 wifi enabled (on the router that is ) and everything seems to be working OK (including a playstation).

No thanks to Virgin though, who provide pretty much zilch in the way of documentation and user guides, and who phone helpline is useless for a non-techy (which is why i ended up being involved) and whose 0845 number costs a small fortune when you call in the first place to get the phone line itself working.

But many thanks for all the help above - i have only be "doing computers" for thirty four years, and there is still a lot to learn

Cheers,

mb