Linux Networking Software

NextDNS, EdgeOS and device names

Noticed that NextDNS was reporting old hostnames in the logs. For example old device names (devices that changed hostnames), devices that were definitely no longer on the network, or IPs that were matched to the wrong hostnames.

The culprit is how EdgeOS deals with its hosts file. Basically it just keeps all the old hosts added and just adds a new line at the end of the file.

NextDNS searches for the first valid entry in that file, which is always going to be an older record.

So the simplest solution I found was the turn off hostfile-update every so often. This clears the hosts file.

So ssh into the device, run configure, and then run these commands:

set service dhcp-server hostfile-update disable
set service dhcp-server hostfile-update enable
Linux Networking Software

Running WireGuard in a Docker container (RPi)

This follows the my two other posts about WireGuard.

Most of this can be copied from the amd64 post — with a minor change for making it work on RPi4. This is the full git repo (including both rpi and amd64).

The main difference is in the file. The installation is a bit different and we’ll need to install the Raspberry Pi kernel headers.

WireGuard is also installed from testing instead of Debian backports.

Note that for older RPi’s (ie gen 1) you’ll need to compile from scratch.

Hardware Linux Networking Software

Resilio Sync on Synology stuck?

The Resilio Sync package that’s provided on a Synology NAS’ Packager Center is out of date (2.6.2) and has a bug that causes big files to fail to sync (and that causes a loop of endless retries).

The solution is to manually update the package from 2.6.2 to 2.6.4. Find your NAS architecture and then download (bottom of the page) the right binary and manually install it.

Note that you need to stop the Resilio Sync service running (manually stop it via Package Center) before uploading the package and installing it.

Once done, don’t forget to manually start the service again.

Resilio Sync GUI will be at <NAS IP>:28888/gui/.

The howto guide to manually update the package can be found here.

Linux Networking Software

Error! Bad return status for module build on kernel: 4.19.0-8-amd64 (x86_64)

I was rebuilding my WireGuard Docker container today and this error started popping up:

Setting up dkms (2.6.1-4) ...
Setting up wireguard-dkms (1.0.20200429-1~bpo10+1) ...
Loading new wireguard-1.0.20200429 DKMS files...
It is likely that 4.19.0-8-cloud-amd64 belongs to a chroot's host
Building for 4.19.0-8-amd64 and 4.19.0-8-cloud-amd64
Building initial module for 4.19.0-8-amd64
Error! Bad return status for module build on kernel: 4.19.0-8-amd64 (x86_64)
Consult /var/lib/dkms/wireguard/1.0.20200429/build/make.log for more information.
dpkg: error processing package wireguard-dkms (--configure):
 installed wireguard-dkms package post-installation script subprocess returned error exit status 10
Setting up build-essential (12.6) ...
Setting up libalgorithm-diff-xs-perl (0.04-5+b1) ...
Setting up libalgorithm-merge-perl (0.08-3) ...
dpkg: dependency problems prevent configuration of wireguard:
 wireguard depends on wireguard-dkms (>= 0.0.20200121-2) | wireguard-modules (>= 0.0.20191219); however:
  Package wireguard-dkms is not configured yet.
  Package wireguard-modules is not installed.

dpkg: error processing package wireguard (--configure):
 dependency problems - leaving unconfigured
Processing triggers for systemd (241-7~deb10u3) ...
Processing triggers for libc-bin (2.28-10) ...
Errors were encountered while processing:
E: Sub-process /usr/bin/dpkg returned an error code (1)

The solution was to install bc. Seems like Debian is not pulling the right dependencies. I’ll be adding it to my Dockerfile.

Linux Networking Software

Running WireGuard in a Docker container (amd64)

This is the 2nd post about WireGuard.

So I am running two WireGuard servers — one on a Raspberry Pi 4, and one in an amd64 virtual machine. This post will be about getting WireGuard working on amd64 in a Docker container.

As this container rarely get rebuild, I am running unattended-upgrades inside the container to make sure security updates are applied.

I am also running Bind9 to act as a caching DNS server inside the container. Ideally this should be running from its dedicated container but that makes everything more complicated and not worth it for what I am trying.

I am also

The public repo that acts as a proof of concept can be found here. — this file starts (or restarts) and builds the container. It will also create the files as needed, set the forwarding DNS server, etc.

Dockerfile — the example will start a basic container based on debian-slim, set up the port forwarding, install the tools we need, and copy over the configs — this file will be executed after the container has been built. We need to install WireGuard from this file or it will fail due to the volume not being mounted and not having the right params.
This will also start the named (bind9) server.
I manually set ip address add dev wg0 because using Address in wg0.conf caused issues. I haven’t recently tested if that’s still the case.

named.conf.options — pretty standard bind9 config file; I want to be in control of my forwarding server because I am using NextDNS and want to apply a different config.

And of course your wg0.conf.

Running docker exec wireguard wg should give details about your connected hosts.