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Sharing a connection with 8+ users (- newbie)


Sharing a connection with 8+ users (- newbie)


I am getting a home user 2mb connnection.
Using a US robotics wireless turbo router and access point. I will be connecting with other PC's using wireless. I will be using a Speedtouch 510 (initially) connected with the router/AP. The router/AP will be connected to my computer via LAN. Is this set up right?

You are only assigned 4 static IP addresses, yet I will be connecting wirelessly with about 10 or more computers.


1. Will more than 3 users be able to use the internet?

2. Does this mean that the host will only have controll over only 3 other users (or 3 groups of users)?

3. Can I use NAT (Network Address Translation) to assign each computer it's own network address regardless of the IP address limit? If so, does the host computer have controll over each individual?

controll = allowing connection to network

Thanks for reading,
excuse my stupidity in this issue Shockedops:

Sharing a connection with 8+ users (- newbie)

Not an expert but:

If using NAT all computers on your network should be able to connect to the internet, surf, mail and news with only a single "public" IP address. I have three computers connected through a router and all can be connected at the same time. I have only a single public IP address.

I think it gets more complicated if you wish to host websites on some of the connected computers.


Sharing a connection with 8+ users (- newbie)

First of all, understand how the 4 IP Address system is supposed to work: see "Figure 2 – A four IP (No-NAT) setup example" on the Networking with ADSL page. In reality, having been allocated 4 IP addresses, you have just two usable addresses, of which one goes to the router (used on both its network interfaces) leaving one for a PC. Other PCs in your network have to be given private IP addresses as shown in the diagram. The PC with the public IP address performs NAT processing at its interface which has the public address. This PC is required to be "up and running" for the other PCs to be able to access the Internet, for they route via this PC. So the No-NAT configuration builds in an additional single-point of failure.

As it says in the article, there's little you can do with this 4 IP address "No-NAT" setup that you can't do with the more common single IP address "NAT" setup, shown in the first diagram of the article. In this, the single public IP address is assigned to the router, which performs the NAT processing. There's no PC acting as a middle-man ("controlling host") so this point of failure is removed, and the PCs only need the router to be available for them to have Internet access -- they do not rely on any other PC.

So you might decide you don't need the 4 IP addresses, and one will serve your purposes equally well. As you see from the diagrams, both allow you to connect more than three PCs.

Coming on to your proposed network, I'm not sure from your description exactly how you intend connecting the various devices. You don't state, for example if the SpeedTouch 510 is a 4-port or single-port model. (And why do you say you will be using this "initially"Huh? As a SpeedTouch 510 user myself I find it incomprehensible that anyone would think of changing!)

If I was doing this myself, I wouldn't buy a wireless router -- a simple wireless access point (WAP) would be perfectly adequate.

I wouldn't use the No-NAT scheme, either. If the speedTouch is a single port model, I would either buy a WAP with a multi-port (say, 4 port) Ethernet switch built in, or I'd buy a WAP with a single Ethernet port and purchase a separate switch (I think you can buy 8 port switches for about £20 now). Even if you have the 4-port SpeedTouch, you may need some extra ports for connecting wired PCs, so a WAP with built-in Ethernet switch, or a separate switch, may still be useful.

So, with this kit, I'd connect the SpeedTouch to the WAP (if they each just have a single port, this may be via the separate switch). Further wired PCs may be connected via the switch or via any spare ports on the SpeedTouch and/or WAP. Wireless PCs would connect wirelessly (!) via the WAP.

If you insist on the No-NAT setup, the question is: which device will take the role of the PC (in that Figure 2) with the public IP address -- the "controlling host"? Your questions (2) and (3) refer to a "host" implying it will be a real PC taking this role. If this is the case, I'd still buy a Wireless Access Point rather than a wireless router or wireless gateway. Rather than a PC you could have a wireless device taking this role, in which case you would need a wireless gateway, and not a simple, straightforward wireless access point. (Many manufacturers refer to these as "Wireless Cable/DSL Routers" or some similar name.)

Let's assume you're sticking with No-NAT (you've been allocated a block of 4 public IP addresses) and you're going to use a real PC as the "controlling" host. So the PC will need two network interfaces, one of which could be wireless (a wired interface is required for connection to the SpeedTouch). A simple WAP is then appropriate for the wireless device, again perhaps with a built-in switch or with a separate switch for any wired PCs. The controlling host could then connect to the WAP either by wired connection (possibly via a separate switch, or direct to a port on the WAP) or wirelessly. Further wired PCs could connect via any remaining ports on the WAP or on the separate switch.

With this No-NAT configuration, these are the answers to your questions:[list=1]
  • Yes, more than 3 users will be able to use the Internet, but they will depend on the "controlling host" being up and running (as well as the SpeedTouch, of course, and possibly the WAP).

  • No, the "controlling" host will have control over all other users (as far as Internet access is concerned) for they all need to route their traffic via this host to gain Internet access. The "controlling host" will have no control over network traffic passing between other hosts on the LAN, however (ie traffic not going to the Internet).

  • There's a misunderstanding behind the question. You don't use Network Address Translation (NAT) to assign IP addresses to other computers, you use Dynamic Host Configuration Protocol (DHCP), and yes, the "controlling host" could be used to assign addresses (the wireless device may also have a DHCP server option). You would have already used all your available public IP addresses for the SpeedTouch and the "controlling host", so you'd have none to assign to other hosts -- therefore the other hosts must be assigned private IP addresses rather than public ones. This leads us on to NAT: since the other PCs are all using private IP adddresses rather than public ones, their addresses must not be used on the Internet (capital "I"), so it is necessary to translate them at the boundary between the public Internet and your private internet. This is the NAT function (it will also do port translation as well as address translation), and will be done at the "controlling host", since it is on the network boundary.[/listShocked]Clear as mud? If so, ask again!