How to update OpenWRT while retaining existing configuration and all custom packages

OpenWRT upgrades itself by saving configuration files from known locations (plus manually defined files), overwriting the partition with the latest firmware and then restoring the saved configuration.

This usually works for the configuration itself, however the process doesn’t take care of any custom packages that were previously installed manually (either through LuCI or with opkg). These packages need to be noted down beforehand and then reinstalled.

How to serve custom DHCP configuration with OpenWRT’s dnsmasq

There are times when you need to filter out what some hosts in the network can or cannot do. When you have a router running OpenWRT this can be done at the firewall level.

But if you’re not much into advanced configuration and just want to completely block out some network hosts from reaching the internet (and hence phoning home) then it’s a lot simpler to do this directly from the DHCP and simply leave them without a DNS and gateway configuration.