Add Persistent Static Routes
For RHEL/CentOS/FedoraEdit file /etc/sysconfig/network-scripts/route-eth0 (eth0 is the device name) and add the following lines and save and exist.
By default route-eth0 file will not be there, need to be created.
For Ubuntu/Debian/Linux Mint
If it is managed by NetworkManager, you can use nmtui to add the static route.
$ sudo systemctl restart NetworkManager