[Dnsmasq-discuss] DHCP packet received on enp6s0 which has no address

[Masin Al-Dujaili]

Hi Buck,

4. Januar 2024 13:09, "Buck Horn via Dnsmasq-discuss" <dnsmasq-discuss at lists.thekelleys.org.uk>
schrieb:

> That config is missing the suggested bind-interfaces option. ;)

Oh, you're right, thanks. But, alas, it still won't work. At least, dnsmasq launches now again:

> root at lan-basics:~# ss -tulpn | grep dnsmasq
> UNCONN 10.23.40.53:53 0.0.0.0:* users:(("dnsmasq"))
> UNCONN 0.0.0.0:67 0.0.0.0:* users:(("dnsmasq"))
> UNCONN 10.23.40.53:69 0.0.0.0:* users:(("dnsmasq"))
> UNCONN 0.0.0.0:4011 0.0.0.0:* users:(("dnsmasq"))
> UNCONN [fd00::2e2:69ff:fe61:fe9f]:53 [::]:* users:(("dnsmasq"))
> UNCONN [fd00::2e2:69ff:fe61:fe9f]:69 [::]:* users:(("dnsmasq"))
> LISTEN 10.23.40.53:53 0.0.0.0:* users:(("dnsmasq"))
> LISTEN [fd00::2e2:69ff:fe61:fe9f]:53 [::]:* users:(("dnsmasq"))

I tested with my tablet, which didn't get an IP address though. The log doesn't show anything like
before with "no address". Just to make sure that there are BOOTP/DHCP requests arriving at the
interface I ran "tcpdump -n -i enp6s0 portrange 67-69"

> tcpdump: verbose output suppressed, use -v[v]... for full protocol decode
> listening on enp6s0, link-type EN10MB (Ethernet), snapshot length 262144 bytes
> 13:40:50.851976 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fc:02:96:86:56:5c,
> length 304
> 13:40:51.937527 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fc:02:96:86:56:5c,
> length 304
> 13:40:53.971511 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fc:02:96:86:56:5c,
> length 304
> 13:40:58.027009 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fc:02:96:86:56:5c,
> length 302
> 13:41:03.084268 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from e0:94:67:ae:71:d0,
> length 282
> 13:41:06.185788 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fc:02:96:86:56:5c,
> length 302
> 13:41:10.843075 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fc:02:96:86:56:5c,
> length 304
> 13:41:11.928110 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fc:02:96:86:56:5c,
> length 304
> 13:41:14.132764 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fc:02:96:86:56:5c,
> length 304
> 13:41:18.427050 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fc:02:96:86:56:5c,
> length 302
> 
> As for DHCPv6:
> It's probably a good idea to concern yourself with IPv6 only once IPv4
> is working.
> Most clients won't use DHCPv6 anyway.
> […]
> You may even find out that you do not need DHCPv6 at all.

See, that's part of my problem: there's DHCPv6 and SLAAC and LLA and more :-).

But let's not digress. I'll get to IPv6 and its secrets after getting dnsmasq to work at all.

--
Besten Gruß
Masin Al-Dujaili