GL-AR300M - Exclude ports from DHCP

alexm2020 · 2020-07-08T13:36:40.029Z

Hi

I am trying to figure out how to exclude the wired lan ports (using wan as lan is set) from the DHCP but still have it active on the WiFi connection. The idea is that I can unplug a device, patch it into the GL-AR300M and reconnect the existing lan to the other port. This then allows me to connect to wifi and browse this entire network.

Can anyone help with this?

Alex

alzhao · 2020-07-08T14:44:41.299Z

I am sorry but can you say another way what you want to do?

EddieA · 2020-07-08T15:45:38.995Z

Set the device with a fixed IP, outside of the DHCP range, and turn off DHCP.

DHCP will only respond to devices that send a request.

Cheers.

alexm2020 · 2020-07-08T16:07:08.623Z

OK,
Overall Situation: I have a wired network that does not have a DHCP server on it. It must not under any circumstances have a DHCP server introduced. There are no direct connection points available so I need to patch the network through the two ports on the GL-AR300M without DHCP being allowed on them. Then I would like to be able to connect to the wifi to access the network so the wifi still needs to be allowed DHCP from the GL unit. I’ve been reading the openwrt forums and it may be something like the “dumb access point” configuration but then with DHCP enabled just for the WiFi port.

Hopefully a bit clearer with that description?

EddieA · 2020-07-08T17:37:42.464Z

alexm2020:

I have a wired network that does not have a DHCP server on it

So all the devices must have a fixed IP and will never ask for a DHCP address, so even if they are connected to a network with a DHCP server, it will never be contacted by those devices.

Cheers.

alexm2020 · 2020-07-08T17:43:54.114Z

Yes. The devices on the wired network all have static addresses. I specifically am not allowed to add a DHCP server to this network, even though as you say it will not issue addresses to devices already set as static.

alexm2020 · 2020-07-09T06:52:13.421Z

I think I have it working now.
Set in access point mode, use wan as lan I’ve set the “Ignore this interface” on the DHCP for the lan but added a static lease for my laptop. It still issues the static lease and ignores all other DHCP requests. I wish I’d thought to try that first, I really didn’t think static leases would be issues if ignore was selected…

sfx2000 · 2020-07-10T03:53:47.143Z

Have you tried AP mode?

That disables the DHCP server in AR300M

WiFi is layer 2, so is ethernet… so you’ll get IP’s from upstream

alexm2020 · 2020-07-10T08:31:59.689Z

It seems that static leases are still issued when ignore this interface is ticked. Which is perfect for my needs here. There is no upstream DHCP server to obtain addresses from. It’s a building automation network so not quite like your regular house or office setup.