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

[Masin]

Hi Buck,

thanks for your hints. Sadly, they don't work.

3. Januar 2024 18:48, "Buck Horn via Dnsmasq-discuss" <dnsmasq-discuss at lists.thekelleys.org.uk>
schrieb:

> That could happen if dnsmasq was ready before the networking stack of
> your OS, or if indeed there would be no address proper assigned to enp6s0.

As I quite often restart the dnsmasq service by
> systemctl stop dnsmasq.service
> systemctl start dnsmasq.service

I think that's not the reason. I can even ssh into the container using that IP address dnsmasq is
refusing to bind to. But in the end the address is already assigned when dnsmasq starts.

> Just to make sure: You did configure a static IP address on the host
> running dnsmasq as DHCP server, didn't you?

Yes, the IP address 10.23.40.53 is statically configured in /etc/systemd/network/enp6s0.network:

root at lan-basics:~# cat /etc/systemd/network/enp6s0.network

> [Match]
> Virtualization=container
> MACAddress=00:e2:69:61:fe:9f
> 
> [Network]
> Description=Local network uplink interface
> LinkLocalAddressing=ipv6
> IPv6LinkLocalAddressGenerationMode=eui64
> LLDP=yes
> EmitLLDP=customer-bridge
> 
> [Address]
> Address=10.23.40.53/22
> Label=Service IPv4
> 
> [Route]
> Gateway=10.23.40.1
> Destination=0.0.0.0/0
> Scope=global
> Metric=2048
> PreferredSource=10.23.40.53
> 
> [DHCP]
> UseTimezone=yes
> 
> Regarding your configuration: Did you try a configuration with just> listen-address and
> bind-interfaces, without interface,
> no-dhcp-interface, and except-interface options?

I try to avoid that because I want dnsmasq to bin to whatevet IPv6 address the container receives.
I'm still new to IPv6 but I want to make it work in my local network. And as DHCPv6 seems to work
quite different I don't know what address to expect for the container.

But it's worth a try.

> root at lan-basics:~# systemctl start dnsmasq.service
> Job for dnsmasq.service failed because the control process exited with error code.
> See "systemctl status dnsmasq.service" and "journalctl -xeu dnsmasq.service" for details.
> root at lan-basics:~# cat /etc/dnsmasq.d/dns.conf
> domain-needed
> bogus-priv
> 
> listen-address=10.23.40.53,fd00::2e2:69ff:fe61:fe9f
> 
> log-queries=extra
> cache-size=1000
> dnssec
> 
> no-resolv
> #domain=wiedner.berlin
> expand-hosts
> no-negcache
> 
> servers-file=/etc/dnsmasq.d/google.dns
> #servers-file=/etc/dnsmasq.d/quad9.dns
> conf-file=/usr/share/dnsmasq-base/trust-anchors.conf

The log shows:

> Jan 04 09:25:53 lan-basics systemd[1]: Starting dnsmasq.service - dnsmasq - A lightweight DHCP and
> caching DNS server...
> Jan 04 09:25:53 lan-basics dnsmasq[446]: dnsmasq: failed to create listening socket for port 53:
> Address already in use
> Jan 04 09:25:53 lan-basics dnsmasq[446]: failed to create listening socket for port 53: Address
> already in use
> Jan 04 09:25:53 lan-basics dnsmasq[446]: FAILED to start up
> Jan 04 09:25:53 lan-basics systemd[1]: dnsmasq.service: Control process exited, code=exited,
> status=2/INVALIDARGUMENT
> Jan 04 09:25:53 lan-basics systemd[1]: dnsmasq.service: Failed with result 'exit-code'.
> Jan 04 09:25:53 lan-basics systemd[1]: Failed to start dnsmasq.service - dnsmasq - A lightweight
> DHCP and caching DNS server.

--
Besten Gruß
Masin Al-Dujaili