OS X merely relies on the servers it has been configured to use (e.g. the DHCP server) to work properly. When the DHCP server assigns your Mac an IP address, OS X doesn't second-guess the DHCP server by saying - no I don't like that one, give me another. That would be like someone asking the Motor Vehicle registration board for a different licence number than the one they have been assigned.
So if the IP address assigned doesn't work to provide a working Internet connection, OS X just assumes that there is something wrong with the Internet connection.

yeah, i understand that is how it works, and that it makes sense...

but, I cannot help wanting the motor vehicle department to issue a new license number to a good working car, when the car with the old license gets a flat tire! :D

P.S. and without waiting in line at the motor vehicle department! ;)

:confused: I don't understand why you're so set against calling your cable provider.

long story, lots of reasons.

outages are only momentary, sporadic, intermittent and infrequent. the downtime would be difficult to diagnose, and even if is quite clear the cable provider is at fault, here the uptime is well above their contractual obligations.

as anyone knows who has had to fight their internet service provider or cable company to provide reasonable service quality even when problems are severe, it is a time-consuming, aggravating, frustrating process.

in recent months i have seen an outage once every couple of weeks or so. even when the problem arose several times a day at its peak, connectivity was always present after re-establishing the connection using the manual steps described above in the thread.

one must choose their battles, thus this is not one i choose to fight the cable provider. i have made several inquiries, receiving the expected denial by the provider of problems on their end.

lastly, and most importantly, it remains desirable to find a solution within my control that can be applied anytime anyone might be confronted with this situation, which i imagine is not uncommon.

imagine unplugging your internet connection for a moment, all your network devices react, you re-plug your internet connection, but your internet services are not automatically utilized by your network until after you manually intervene.

that may be the expected and proper behavior under the circumstances, or even under the definitions and standards and requirements of networking protocols and technology, but it is nevertheless annoying, aggravating and time-consuming each time.

So, it would be ideal to find a technical solution that one can implement to avoid the problem entirely, given the fact of life that no internet connection will ever have 100% uptime reliability.

Unix also depends on BIND and DNS a lot and if it is taking a long time to reverse look up the DNS it could cause a delay in the time it takes to get a valid connection.

Does this problem repeat with Windows? Since it is not as DNS dependent as Unix or Linux, that is if you have access to a windows box.

Well, you could check for signal leaks yourself. Coaxial cable plugged into the wall socket, but not connected to a TV or cable modem on the other end could cause a problem. Anywhere that the wire in the center is exposed or the braided shield is frayed can cause signal leak. If the exterior cable is old or in a spot that might allow for excessive wear, look for cracks or exposed wire. If you find physical problems, you could easily use that to get a technician sent out. Once they're there, it should be easy to get them to replace a cable or filter.

Try turning on the UNIX Name Service BIND (Berkeley Internet Name Domain) via root terminal. It's built into OSX (as OSX is UNIX based) but off by default (not sure about Leopard) for some odd reason, but it's the UNIX native DNS. Well it's actually a suite of UNIX based utilities including nslookup and dig but contains a very good DNS server that may fix your problem if it's DNS related.