DHCP on wireless

[Juan Pablo]

This is not really a Linux issue but I thought somebody with more networking knowledge than me may be able to help me.

Bought an access point this morning, I connected it to my wired router which is connected to my cable modem, then I configured it and changed my SSID.

My network topology is like this

----- : Means wired
-*-*-*-*: Means wireless

Cable Modem --- Wired router --- Access Point (192.168.0.50) -*-*-* My laptop (DHCP)
| |
* *
| dad laptop (DHCP)
brother laptop (DHCP)

The DHCP server (my ISP) assigns me (my laptop) an IP, but it doesn't assign an IP to my dad or my brother laptops

My laptop can browse the internet without problems but the others (without an IP) can't

I also tried to copy the IP in my laptop and assign it to my dad laptop and it doesn't work either

I also tried to put an IP on the same range to all the laptops connected to the wireless access point, it worked flawlessly as a network without internet but once I try DHCP it doesn't work

I can even shut down my laptop and the other computers can't get an IP through DHCP

I have tried it on both, Linux and Windows and it fail miserably




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The graph doesn't show correctly, will post drawing later

[Dapper Dan]

Hi Juan Pablo,

Sorry to hear of your problems.

I hope I'm understanding the problem correctly but forgive me if I'm not addressing it in the right way. I have a similar situation at my radio station except all boxes within the network use static IP's. I think everything would be the same using DHCP though. I'll just tell you what I'm doing and hopefully it will help shed some light.

We use a DSL modem to a router then to the separate computers. DHCP could be setup to run inside the router so it would assign local IP addresses to all computers on the local network. The IP of each computer is assigned by the router, not the ISP. All boxes are provided with the router's IP ( the gateway) and that tells each where to find their way onto the Internet.

The access point, if it is like mine, should just make all traffic flow between the various computers and the router.

I feel like this hasn't helped much, but wanted to try anyway...

[framp]

Your pic looks strange: Your dad an brother are connected to the moden .... I think they are connected to the router...
I'm sure your labtop doesn't get an IP address from your ISP. Its the router who gets the IP address and you have a local IP address. Just use ifconfig/ipconfig on your labtop to get your local IP.
Which IPs do your dad and brother use?

Looks like your router has to be reconfigured.

[Juan Pablo]

The pic is really strange, vBulletin deleted the spaces I used to drwaw the graph, check this one



Accidentaly, while I was stressed and sleepy because of this problem I wrote Router instead of Switch
Do I need a router after/before the switch?


Let's make it basic


How can I share my cable internet connection through wireless? The IPs are usually assigned through DHCP, it works If I connect the computers directly to the switch

This makes me remember my first days with Linux

[dilbert]

I think you need only a router and you don't need the switch.

As the other posters already have said, your switch is getting ONE IP address from your ISP. That you can use for ONE computer or for a router.

The router stays with the ISP's IP address and builds up a local network where you can attach the computers.

Maybe it would be working with the switch if you would set up one of the computers as a router, with two NICs or wireless cards, and attach the other computers to your computer acting as a software router.

BTW:
I don't understand how can you attach the computers of your dad and brother directly to the cable modem.
What sort of cable modem is this? Does it have an integrated router?
How many network sockets does it have?

[antidrugue]

How can I share my cable internet connection through wireless? The IPs are usually assigned through DHCP, it works If I connect the computers directly to the switch

Can't your Access Point run a DHCP server of its own?

I mean, your ISP can only assign you one public IP address, there is no way around this.

Nevertheless you should be able to run a DHCP server from your Wireless Access Point (and essentially do NAT), so that all computers in your network are assigned private IP addresses.

[Juan Pablo]

Sorry for the delay, my internet connection was down

As the other posters already have said, your switch is getting ONE IP address from your ISP. That you can use for ONE computer or for a router.
The router stays with the ISP's IP address and builds up a local network where you can attach the computers.

This should explain everything

Maybe it would be working with the switch if you would set up one of the computers as a router, with two NICs or wireless cards, and attach the other computers to your computer acting as a software router.

I have my old desktop computer under my desk without use, I will set it up as a headless router

I don't understand how can you attach the computers of your dad and brother directly to the cable modem.

I can't, I use the switch for this

Can't your Access Point run a DHCP server of its own?

Yes (continued below)

Nevertheless you should be able to run a DHCP server from your Wireless Access Point (and essentially do NAT), so that all computers in your network are assigned private IP addresses.

I have tried this but the computers with the private IP addresses don't get internet this way

[MikeTbob]

I have tried this but the computers with the private IP addresses don't get internet this way

I know this is a dumb and simple question, but did you set up your resolv.conf file?

I agree with the other posts, remove the switch for now, just use the router and your wireless AP to assign IP's

[Juan Pablo]

I know this is a dumb and simple question, but did you set up your resolv.conf file?

Yes, of course, it can't even ping using internet IP addresses

[Juan Pablo]

I don't know, now everything worked magically ... it works! no routers! no switch! no DHCP server on the AP! Just the AP plugged to the modem, WPA and nothing else!!
All the computers work perfectly!

I don't know how it works in the US, but here ISPs can give you up to 5 public IP addresses