What do you mean by "can't get out on a consistent basis"?
For example: take a site like yahoo. Chances are yahoo.com is not going to be offline or be taken down for maintenance. If you don't change anything in the server, and you can ping hit yahoo.com sometimes and sometimes it times out, chances are there's nothing wrong with your server configuration, and you will need to look at other things like the NIC, cable, internal network traffic, firewall, etc.