Store the mesh ip in /etc/config/network. The point is that 'uci commit network' will store the generated ip address anyway. This also makes it consitent to store the ip in /etc/hosts. Also, we store the mac in /etc/config/network now - changing the mac would not change the ip anymore automatically. Btw., setting network.mesh.macaddr does not have an effect on it's own since it a bridge.