IP Networking

I have a question concerning networking. Could any forum
members explain to me why I might be getting "no route
to host" messages when I try to connect through ftp and
http protocols?

I have went to my etc/hosts file and everything seems to be
configured properly. I can connect within my own network.
but cannot connect outside my network.

I am using Sco openserver 5.0.6.

the etc/hosts files defines ip address and associates hostnames with those addresses, essentially the hosts file is like a small name server, or more correctly a name database. the first thing your computer looks at when you try to connect to a website or anything on the net with a name, the computer looks at the /etc/hosts file first. so this is not the file where you set up your routing. without that default gateway you cannot connect to the internet. now, to set that up first you must find out what your default gateway is, you have to contact your isp. if you have broadband like dsl or cable, and you are using a router, your default gateway probably is 192.168.1.1 or 192.168.0.1. to set this up you will need to visit the man pages for ifconfig, and route.
man ifconfig
man route
now to set your default gateway, you do that with route. the man page for route does a good job of telling you how to do that. make sure you include the GW parameter when you figure our how to use route, this parameter tells your system that the ip address you supply will be the current default gateway. after that, you should be up and running!