[systemd-devel] DHCP Server on multiple interfaces

[Martin Townsend]

On Thu, Oct 17, 2019 at 4:55 PM Martin Townsend <mtownsend1973 at gmail.com> wrote:
>
> Hi,
>
> Does systemd support the networkd DHCP Server on multiple network
> interfaces.  I ask as we have an embedded system running systemd 239
> and we want to configure a DHCP server on a bluetooth PAN and one of
> the Ethernet interfaces both of which are used for configuring the
> device.
>
> I've set up both the network files with
> [Network]
> ....
> DHCPServer=yes
>
> [DHCPServer]
> PoolOffset=10
> PoolSize=10
> DefaultLeaseTimeSec=12h
> MaxLeaseTimeSec=24h
>
> When trying to connect to the bluetooth PAN I get
> Oct 17 15:28:39 vasig-imx6ul-txul-emmc systemd-networkd[307]: Failed
> to determine timezone: Invalid argument
> Oct 17 15:28:39 vasig-imx6ul-txul-emmc systemd-networkd[307]: pan0:
> Could not start DHCPv4 server instance: Device or resource busy
> Oct 17 15:28:39 vasig-imx6ul-txul-emmc systemd-networkd[307]: pan0: Failed
>
> The message " pan0: Could not start DHCPv4 server instance: Device or
> resource busy" seems to suggest that only one server instance is
> allowed.  Weirdly the device connecting did get an ip address.  But if
> I look at the status of the pan0 I see:
>
> root at vasig-imx6ul-txul-emmc:~# networkctl status pan0
> ● 4: pan0
>        Link File: /lib/systemd/network/99-default.link
>     Network File: /etc/systemd/network/30-pan0-bridge.network
>             Type: bridge
>            State: routable (failed)
>           Driver: bridge
>       HW Address: 82:2f:45:2a:9c:5a
>          Address: 192.168.10.1
>
> eth0 is named such that it should be configured before the pan0.
>
> Best Regards,
> Martin.

I think I have hit this issue as the PAN does have
ConfigureWithoutCarrier=yes

https://github.com/systemd/systemd/issues/9479