Access point as DHCP server

Question

My level of knowledge on networking is moderate.

I have the following scenario:

1. Our internet connects to the LAN into a normal port (Dlink DS 1008D Switch)
2. Some of the computers in the office connect directly to above switch.
3. Running from the switch is a cable that connects a Wireless G access point with another 4 ports.
4. We realised that when more than 5 computers connect to the internet at the same time, a sixth computer cannot connect (we are assuming that our ISP has allocated only five IP's to us.)
5. We are trying to solve this by making the Wireless access point a DHCP server. The thought is that the accespoint occupies only 1 IP from the ISP, but that we can connect many more to the network and still access the shared internet connection as the IP's are then locally generated.

What I've done was activate the DHCP function on the access point, connected the cable coming from the switch to the WAN port. It reads the ISP and gets an IP address, it also assigns IP adresses to computers that connect to it, however, we cannot access the internet from those computers, and we can also not see any of the computers that are on the switch.

I'm thinking that the relationship between the switch and the accesspoint is the problem and that I should have the internet coming in straight to the accesspoint and from there to the switch instead of the other way round? Will try this in a while as I cannot disconnect the network right now, but is my thinking right?

Can anybody help by indicating if they think I'm doing something wrong?

Answer 1

You should really be liaising with your ISP to find out precisely what they have configured for you.

As Journeyman Geek's comment points out you may only have a set number of IPs from your ISP but (again, this is where contacting them will get your answers) you should be able to install a router between your ISP connection and your D-Link switch (and thus your AP also) which gives your network the ability to expand only using ONE of your ISP's IP addresses.

The router will perform NAT (https://en.wikipedia.org/wiki/Network_address_translation) which will allow almost any number of "internal" devices to communicate through the single IP your ISP provides. This is how home (and business) connections work to allow multiple devices to work down one line.

I can't stress enough, however, the importance of communicating with your ISP to find out if they can offer you a solution (or at least answers) to be able to install your own router. You can then use the router as your DHCP server and it will take care of your entire LAN's addressing and allow (almost) as many clients as your LAN requires. If you have another DHCP server on your LAN then you must disable all other DHCP servers to prevent conflicts.

Answer 2

Assign Manually IP Addresses, Default Gateway and DNS for all six computers. then all computers can connect to the network.