I believe you want KeepConfiguration="static".
On Wed, Sep 13, 2023, at 18:32, Jeremy Friesner wrote: > Hi all, > > I apologize for this basic question, but I haven’t been able to figure it out > on my own. > > I’m working on an embedded device, which includes a little GUI that (among > other things) allows the user to specify a static IPv4 address (and netmask > and gateway) to be associated with a given Ethernet port on the device. > > The user enters the IPv4 settings-values he wants into the GUI, clicks > “Apply”, and the server runs a couple of simple shell commands: > > /sbin/ip -4 a add 192.168.2.88/24 dev eno1 label eno1:p0s0 > /bin/arping -c 3 -A -I eno1 192.168.2.88 > > … et voila, Ethernet device eno1 now uses the IP address 192.168.2.88 > (associated with the label eno1:p0s0), as shown in ifconfig: > > root@embedded-device:~# ifconfig > […] > > eno1:p0s0 Link encap:Ethernet HWaddr 00:07:32:95:93:7D > inet addr:192.168.2.88 Bcast:0.0.0.0 Mask:255.255.255.0 > UP BROADCAST MULTICAST MTU:1500 Metric:1 > Memory:a5b00000-a5b1ffff > > If the user later changes his mind and wants to clear his IPv4 settings, he > can do that and the server will run this shell command: > > /sbin/ip -4 addr flush label eno1:p0s0 > > This all works fine and has for a long time; the problem is that the new > version of the device is running systemd.networkd and networkd has some > functionality in it where it detects when an Ethernet device has lost its > carrier, and responds by removing all the IPv4 addresses associated with that > Ethernet device. > > The user-visible result of that behavior is that if the user unplugs his > Ethernet cable and then plugs it in again, his IPv4 settings are no longer in > effect (at least not until he goes and re-enters them into the GUI again to > re-establish them). > > The behavior I would like is that this manually-assigned IPv4 address is left > alone by systemd, and doesn’t change unless/until the user explicitly updates > it using the GUI. Is there some way to convince networkd to leave my > server’s IPv4 settings alone? > > I tried various permutations of config files, like the one shown below, but > they didn’t seem to have any effect on networkd's behavior. > > root@embedded-device:~# cat /etc/systemd/network/eno1.network > [Match] > Name=eno1 > > [Network] > DHCP=no > IgnoreCarrierLoss=yes > > [Link] > ActivationPolicy=always-up > > Thanks, > Jeremy > NOTICE: This email may contain confidential information. Please see > https://meyersound.com/legal/#email-policy for our complete policy.
