Zerotier one limit routes, here is a workround
If you know your zerotier one ip with a private subnet you can add a route:
sudo route add -net 10.0.0.0/24 gw 192.168.1.71
to delete:
sudo route add -net 10.90.90.0/26 gw 192.168.1.141
where 192.168.1.0/24 is a zerotier one subnet, to automate this you can create a systemd service with dependency of zerotier and delay for 10 sec for example
sudo systemctl edit --force --full 10.0.0.0-route.service
[Unit]
Description=10.0.0.0/24 route
After=zerotier-one.service
PartOf=zerotier-one.service
[Service]
RemainAfterExit=yes
Restart=on-failure
ExecStartPre=/usr/bin/sleep 10
ExecStart=/usr/sbin/route add -net 10.0.0.0/24 gw 192.168.1.141
ExecStop=/usr/sbin/route delete -net 10.0.0.0/24
[Install]
WantedBy=multi-user.target
sudo systemctl enable --now 10.90.90.0-route.service
RemainAfterExit=yes - without this option, the route is created and removed right after creation
PartOf=zerotier-one.service - with this option, the service will be restarted if the main service is restarted