Thanks to you all for the tips on ping (ICMP)! I don't understand it well enough but will be reading more about it. The problem here was solved (turned out to be a bind misconfig. that was not a syntactic error, thus hard to find with all the bind differences in doc. examples out there).
DSL with one IP is running servers here, now, so the documentation will begin. ...need to add the other machines here. Thanks again, for all the help, and send any questions about NAT for DSL access (for the Cisco 675) with one public IP my way. I'll be at the regular job intensely for the next three or four days but will try to answer any such questions or collaborate to find solutions as soon as possible. Art