DGA0122 Static Routes
It is possible to add static routes, but only with IPv4.
Web interface
The engineer web user can add static routes on the WAN or WWAN under the Local Network tile, Extras tab.
SSH interface
The engineer SSH user can use the route command to add static routes.
route add --net 192.168.100.0 --netmask 255.255.255.0 --gw 81.187.xx.yy
Any routes so added don't survive a power cycle. The apply command doesn't change this behavior.