Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!rpi!clarkson!grape.ecs.clarkson.edu!nelson From: nelson@sun.soe.clarkson.edu (Russ Nelson) Newsgroups: comp.protocols.tcp-ip Subject: Is the DNS "working"? Message-ID: Date: 19 Apr 91 04:06:37 GMT Sender: usenet@grape.ecs.clarkson.edu Reply-To: nelson@clutx.clarkson.edu (aka NELSON@CLUTX.BITNET) Organization: Clarkson University, Potsdam NY Lines: 66 In-Reply-To: someone's message of 16 Apr 91 In article <1234@foo.bar> name@changed.to.protect (The Guilty) writes: Hi, there, Could somebody mail me the common pc-ftp sites' IP address to me ? My computer cann't check the site's internet name. Thanks, Per the quoted message, I'd have to say "No, the Domain Name System (DNS) is not working". Requests like these are not uncommon. They would be even more common except for the fact that people publishing site names have learned to include the IP address. I run a well-used archive site (grape.ecs.clarkson.edu) that recently (Feb. 20th) changed its IP address. Since then, we have kept a "victim" PC running on the old IP address [128.153.13.196]. The home FTP directory on this PC has files that direct a user to the new IP address. In the past six days, we have had 287 FTP sessions initiated at the OLD IP address. This, to me, is evidence that users have learned to avoid using host names, preferring to use IP addresses. I suppose it's a little unfair to lay the blame at the feet of the DNS. After all, hosts using the DNS can simply FTP to grape. Or, if your host doesn't use the DNS, a moment with nslookup or dig will get you grape's IP address. But it is exactly this latter case that causes the problem. On these hosts, a user must use a program that prints the IP address, then they must reenter the IP address to the FTP client. Once you know the IP address of a machine, why look it up again? Fairness, then, would dictate laying part of the blame on those system administrators who use /etc/hosts in preference to the DNS. And for the sake of truth, both I (on grape) and the sysadmin of sun.soe.clarkson.edu refuse to use the DNS (consider this message a confession, and the TCP-IP list the confessional). For my part, the OS on grape.ecs.clarkson.edu experienced kernel crashes when using the DNS. I went back to /etc/hosts and the crashes went away. But I think that's a minor problem. A more serious problem is faced by servers on the Internet. On the one hand, the sysadmin would like users to be able to access any machine on the Internet, and that means using the DNS. On the other hand, the sysadmin MUST (at least this one must) keep the machine running even if access to the name server is cut off, even temporarily. A typical plaintive user cry is "Why can't we use sun.soe.clarkson.edu just because omnigate.clarkson.edu is down?" Perhaps there is a work-around. If there is, it's not well documented, because as I showed earlier, sun.soe.clarkson.edu is not the only machine relying on /etc/hosts. I think we need a hero to document the work-around. I don't think the grand Usenet tradition of volunteering the complaintant should apply in this case because I'm not the sysadmin on sun.soe.clarkson.edu. Besides, I don't *know* what the work-around is. I just want the person who DOES know to step forward, or at least to remain still while the rest of us step backwards. Thank you, you wonderful person, whoever you might turn out to be. -- --russ I'm proud to be a humble Quaker. It's better to get mugged than to live a life of fear -- Freeman Dyson I joined the League for Programming Freedom, and I hope you'll join too.