DGA0122 CLI
This probably applies to most Technicolor routers.
There is a command line interface, which can be accessed from the LAN with ssh using the engineer username and the admin password.
The CLI is fairly minimal, there is no manual. The router's firmware is a customised version of OpenWRT, that project's documentation may help.
It is possible to mess up the router configuration in many ways if you don't know what you're doing!
N.B. If you choose to play with the CLI, the rtfd command will reset the router to factory default setting, without any warning or Y/N prompt.
Useful commands
The route command can be used to add static IPv4 routes:
route add --net 192.168.100.0 --netmask 255.255.255.0 --gw 81.187.xx.yy
Such routes don't survive a reboot.
It's not clear whether the apply command is needed.
Variables
The router is configured using a vast number of config variables. You can get a full dump of the current config with
get InternetGatewayDevice.
(note the trailing dot). Variables can be written to, e.g.
set InternetGatewayDevice.LANDevice.1.LANHostConfigManagement.DHCPLeaseTime 3600
The changes are applied after a reboot.
Similarly the OpenWRT config variables are accessed from
get uci.
Don't expect much sympathy from AAISP staff when you've badly reconfigured your router.