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+---
+title: "Adventures on server setup without a monitor"
+date: 2024-11-18T21:41:35-08:00
+tags: ["networking"]
+ShowToc: false
+---
+
+A story of frantically rescuing a deployed headless server, where I forget to statically assign an IP address. 
+It just won't have network connection. No SSH. No fixie.
+
+Except _there is nothing saying a DHCP server has to be running on the router or gateway_.
+So, just install and configure `kea` (or a DHCP server of your choice) on any other computer on the network, reboot the server in question, and voilà!
+SSH to your hearts content.
+
+---
+
+So the story goes like this.
+I recently got hands on a nice little old desktop tower, plenty of RAM and a good number of SATA ports for selfhosting: Seafile, Immich and what not.
+Now it _is_ rather old machine, with only VGA and DVI on the motherboard. This means my little trusty HDMI to USB video capture dongle won't be helpful!
+I also need to deploy this machine to my parent's house, for I plan on giving them access to a photo backup solution.
+I need to bring a monitor that has a VGA port on it.
+
+So I at the comfort of my home, I took some time to install Debian, as well as all other packages I could possibly need. Also configured a SSH key.
+
+And as all good stories go, the _one thing_ I was supposed to do was not done. I didn't assign a static IP to `eth0` beforehand.
+
+_Uh. oh._
+
+There is no proper DHCP in the lan, I had everything else setup with static IPs. I don't know its MAC, so no calculating SLAAC by hand to get a link local IPv6 either. In fact, if I remember correctly I don't even think the gateway was properly setup with IPv6 at all.
+
+No network, no SSH.
+
+No monitor, no way to see what's happening on screen to configure its WiFi connection properly.
+
+Quickly, I thought "what if I could just type out all the commands without a monitor?"
+Trying to open vim on `/etc/network/interfaces` and blindly modifying a complex configuration file obviously did not work so well.
+Although I did figure out one helpful tidbit: since this machine has a beeper, I can run things like `foobar && tput bel` in TTY to get an audio confirmation that something succeeded.
+
+After ten minutes of desparately trying various commands and questioning if I had been making typos all along, an enlightenment suddenly found its way into my mind: nothing is stopping me from running an ad-hoc DHCP server just for this purpose!
+As far as I know, all of the networking implementations shipped by various Linux distros default to DHCP. This includes `NetworkManager`, `systemd-networkd`, or even Debian's default networking setup.
+
+[Kea](https://www.isc.org/kea/) is apparently the recommended implementation, so I installed it on my laptop, and after some fiddling of configs per the [ArchWiki](https://wiki.archlinux.org/title/Kea) (because ArchWiki is the one wiki to rule them all), it did work. The server allocates the first address in the pool, so I just picked `192.168.233.1/16` and successfully SSH-ed in.
+
+No need to drive 30 minutes round trip to get my VGA monitor!