Troubleshooting
If you cannot access the Internet through the firewall, start the troubleshooting process:
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Make sure that you've restarted all of the processes on the firewall computer after making the configuration changes, or that you've restarted the computer, which will also restart the processes.
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Make sure that you can ping a server on the Internet from your firewall computer. If you can't, there is a problem with your connection to the Internet. Fix that problem first, and make sure that your firewall computer can properly connect to the Internet.
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Make sure that you can ping the firewall computer from a computer on your internal network. If you can't, there is a problem with your internal network setup.
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Check the network settings. Look at the IP address, gateway, and DNS settings on each computer that is connecting through the firewall.
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If you are using Ethernet wiring, make sure that all of the connections are good.
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Make sure that the hub is powered on and configured properly. Some hubs have an uplink button that is pressed on when the hubs are chained together and pressed off when it is being used as a single hub. Check the lights on the hub—an LED light usually glows if the link is active.
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Check the rc.ipchains file in the /etc/rc.d directory to make sure that it matches the sample file. Look for missing characters or punctuation; a misplaced comma or a missing hyphen can break ipchains.
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Check the logs in /var/log/messages or /var/adm/messages for any firewall errors. This can tell you what needs to be fixed.