Yep. But I did say a factory reset and re-load, not a reboot .

Edited by RobertoS (Sun 13-Jan-19 21:26:07)

In reply to a post by RobertoS:

Yep. But I did say a factory reset and re-load, not a reboot .

Potentially quite a lot of work depending on how many devices. Much easier to reduce the lease time.

I have seen DHCP servers in companies where they had a lot of mobile staff (laptops and phones/tablets coming and going) where they did not have enough IP addresses, so the lease time ended up at 10 minutes.

It worked.

Ah, we are at cross-purposes. I was thinking of a dedicated device setup for despatch router. Not a traffic routing one.

I assumed they�d need internet, but nothing to stop plugging a second into a first and using second as you described.

I just don�t think it would be needed to go to the effort you describe.

I've bought and installed a Draytek 2862 and so far all looks good.

On the lan side I've configured the network at 192.168.1.1/22 which allows for 1024 IP addresses ( less 0 and 3.255 ).

The Draytek DHCP server is running on the network up it seems to only want let me have a pool size of 752 rather than nearly 1024. 752 is fine for my needs. Also, I can set the lease time to 120 seconds which means the IP addresses will be freed up quickly.

Hope you still got sorted.

For others who visit this after:

It's poor practice to have massive subnets (e.g /16) with DHCP - hence it most likely will be difficult to find a router with a large subnet capable DHCP address size. Subnets like a /23 or /22 should be ok for a decent SOHO router.

I'd recommend a few things:

- Splitting up your networks into smaller subnets.

- Set your lease time a little above what you expect commissioning time of the devices you're setting up. e.g. If it takes your about an hour to commission a device then set lease timer to 4 hours or something. I'm not sure the rhythm you have on setting up the devices - but take that concept. Meaning, by the time a DHCP lease expires you'll be well finished commissioning the device(s).

- Clear ARP each morning when you come in - might be an option. Again depends on how you're chain commissioning devices.

- Investigate writing a script to automate refresh. Either - script on the device you're setting up.. OR a script to test IP ranges for ping response, and if failed response, runs a command on a router to clear that ARP entry.


I personally would see about adding/script to release its IP when done.

For example - if commissioning hundreds of laptops - I'd have a USB pen with all my software I was installing then a final batch script on it to run "ipconfig /release" in command prompt - which will tell the DHCP server that the IP is now available for another client.