Intermittent internet connectivity

Hello,

I am a relative UNIX newbie and we are unable to get out to the internet past the router. I can ping everything within the network but can't get out on a consistent basis. The UNIX DBA was let go recently and I have had to step in and assume his duties. Unfortunately, I am not quite up to snuff on UNIX and am having a problem determining what is causing the intermittent connectivity issue. From what I can tell, there have been no changes within UNIX or on the Solaris box and I was hoping to solicit some suggestion from anyone that may have had a similar issue.

There is probably system or ip information you may need to help diagnose the problem so just let me know what would be helpful and I'll provide the information.

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.