Add default gateway while installing Debian

Question

I have in my virtual infrastructure static ip addresses and have to set the gateway which following commands:

post-up route add x.x.x.254 dev eth0
post-up route add default gw x.x.x.254
post-down route del x.x.x.254 dev eth0
post-down route del default gw x.x.x.254

Is there any possibility to set them with in the netinstaller?

Edit:
Press [Alt] + [F2] for the second terminal. To enable it, press [Enter] and add the routes with following commands:

route add x.x.x.254 dev eth0
route add default gw x.x.x.254

Answer 1

Open a shell from the installer main menu and do the networking setup by hand. Then continue with the next installer step after the network setup.