[Dnsmasq-discuss] dnsmasq not overriding leases for static assigments
Geert Stappers
stappers at stappers.nl
Sun May 16 14:06:58 UTC 2021
On Sun, May 16, 2021 at 02:13:37PM +0100, Jesus M Diaz wrote:
> On Sun, 16 May 2021 at 13:48, Kristof Burek wrote:
> > > ....
> > How do you know that the client is requesting the same IP address? (Have
> > you been able to sniff the packets?) Does the client "know" when its MAC
> > address has changed?
>
> That's an easy one,
Okay. Here other easy one: Reply below previous text.
> I have the 'old' lease, the dnsmasq config and logs,
> and tcpdump sniffing (see below). But the short story is:
>
> 1. device asked some time ago for an ip-addr, and as it is configured to
> get a static one, it got it (logged in the 'old' lease)
> 2. device disconnect from the router and connects to one AP, and after
> reconnecting, request the same ip-addr with a new mac-addr
a.k.a. DHCP renewal
> 3. dnsmasq sees the 'old', and before even checking anything else (I
> know this because there are no 'tags' assigned to the device), respond with
> 'address in use'
Actual "IPv4 address in use"
> 4. device requests for a new ip-addr with the new mac-addr
That new MAC address is the root cause of the "problem".
> 5. dnsmasq identify the client (assigns the tags 'known' -it is in the
> config file-, 'eth0' -interfaz-, 'mobile' -assigned to this device in the
> config file- and 'pasillo' assigned in the config file to all devices
> connected to that AP.
I don't understand that . I think it tries to explain "available IPv4
address in best fit dhcp-range".
> 6. dnsmasq, despite having identified the client,
And how did that identification happen???
> assigns a new ip-addr because the old one is in use.
Which is good.
Groeten
Geert Stappers
--
Silence is hard to parse
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