Default Route on OpenWRT

When I create a new linux virtual system and use OpenWRT at home to route out to the internet, I need to add a default route so that I can get out to the Internet. For some versions of linux, it doesn't do it automatically for me (or maybe it's the OpenWRT router and something I've misconfigured as it works for some systems, but not others?). The command to do this is:

route add default gw 192.168.8.8

Then to delete the route on one of the Virtual Machines, like pc036, I can use the command route delete, like this:

route delete default gw 192.168.230.11