[Dnsmasq-discuss] Lease duration for hosts without names

[Dan Schaper]

You can use --dhcp-host to tag or otherwise dispense with clients based 
on mac address. You can also specify mac addresses with a * wildcard 
byte, so you might be able to leverage the fact that randomized mac 
addresses follow a pattern.

Per https://www.rfc-editor.org/rfc/rfc7042.html#section-2.1 the local 
bit is set, meaning that the mac addresses will be in the form of 
x2:xx:xx:xx:xx:xx, x6:xx:xx:xx:xx:xx, xA:xx:xx:xx:xx:xx, 
xE:xx:xx:xx:xx:xx. What I'm not sure of, and would need testing, is if 
you can use wildcards for part, like *2:*:*:*:*:*

Apple's MAC randomization is _supposed_ to be per WiFi SSID, so each 
device _should_ only have one randomized mac address per SSID. I don't 
really think it works that way in the real world.

Dan

------ Original Message ------
>From "Jay Guerette" <jayguerette at gmail.com>
To donmuller22 at outlook.com; dnsmasq-discuss at lists.thekelleys.org.uk
Date 7/18/2025 8:16:21 PM
Subject Re: [Dnsmasq-discuss] Lease duration for hosts without names

>
>I should have been more explicit in my ask. I know how to fix it but I 
>want to prevent it in the future. When I'm not around I want my network 
>to work without intervention.
>
>Most people don't know what a MAC is, don't know where the setting is, 
>and may not react well to "you have to disable privacy if you want to 
>use my wifi". The smaller pool size & longer lease length could be 
>considered short-sighted or self-inflicted. I didn't anticipate guests 
>requiring 4+ IPs on my network each and constantly acquiring new ones 
>without releasing the old ones.
>
>I think that hosts that don't provide a name are either mis-configured, 
>poorly designed, or just privacy focused. We already have 
>'dhcp-generate-names' that identifies these hosts, I'm wondering if we 
>could extend the concept to allow you to add a tag to such hosts so 
>that specific policies could be applied.
>
>
>On 7/18/25 6:40 PM, Donald Muller wrote:
>>Have them turn off MAC randomization or modify your dnsmasq config to increase the pool or set a short lease time while they are guests.
>>________________________________
>>From: Dnsmasq-discuss
>><dnsmasq-discuss-bounces at lists.thekelleys.org.uk> <mailto:dnsmasq-discuss-bounces at lists.thekelleys.org.uk> on behalf of Jay Guerette <jayguerette at gmail.com> <mailto:jayguerette at gmail.com>
>>Sent: Friday, July 18, 2025 6:01 PM
>>To:
>>dnsmasq-discuss at lists.thekelleys.org.uk<dnsmasq-discuss at lists.thekelleys.org.uk> <mailto:dnsmasq-discuss at lists.thekelleys.org.uk>
>>Subject: [Dnsmasq-discuss] Lease duration for hosts without names
>>
>>
>>I have some house guests who brought devices that randomize their macs and don't provide host names. Due to their usage patterns they quickly exhausted my small DHCP pool.
>>
>>Is there a way that I can tag hosts that don't provide a name so that I can provide a custom/shorter lease time?
>
>
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