From your post, it sounds like maybe the network interface is not being configured automatically when you boot. Since you didn't mention it, the first suggestion is to create a file
/etc/ifconfig.rtk0. The bootup scripts should find this and provide the contained lines as parameters to the ifconfig command. E.g., the file might contain something like:
Code:
inet 198.168.2.x netmask 255.255.255.0 media autoselect
For more details, have a look at the man page
ifconfig.if(5)
Hope that helps.