Brian.Chan@samba.acs.unc.edu (Brian Chan) (03/28/91)
I hope this is the right newsgroup for my question: how do you find out the host numeric addess (eg 128.x.x.x) if you only know its name like foo.bar.edu? Nicname and whois only work partially. If a site is not registered at some location, how can you find out this numeric address besides sending mail to root@foo.bar.edu? Thank you very much for your time, Brian Stuttgart, FRG -- ============================================================================= Extended Bulletin Board Service, Research & Development Office of Information Technology, University of North Carolina at Chapel Hill internet: bbs.acs.unc.edu or 128.109.157.30
jik@athena.mit.edu (Jonathan I. Kamens) (04/03/91)
In article <3131@beguine.UUCP>, Brian.Chan@samba.acs.unc.edu (Brian Chan) writes: |> how do you find out the host numeric addess (eg 128.x.x.x) if you only |> know its name like foo.bar.edu? I'm assuming that you're using a machine that uses Internet name service to resolve hostnames, rather than a large /etc/hosts table. If your site uses /etc/hosts, then go find your site admin, shoot him, and then replace him with a site admin who will upgrade your software so that it uses Internet name server (that's a joke, OK? :-). You can use the bindtest, nslookup or dig utilities to find out an Internet address given a host name. All of those utilities have sources floating around the net; if you can't find them and want to, let me know and I'll see what I can dig up. Alternatively, if you're not interested in the complexity of those utilities, you can just write a short C program to call gethostbyname() on the string you pass it, and then print out the address in the data that is returned using inet_ntoa. In fact, we've got a utility here to do that. I've shar'd the source file and the man page together into a shar file and put it in /pub/tmp/hostinfo.shar on pit-manager.mit.edu (18.72.1.58). It's also retrievable via E-mail by sending a message to "mail-server@pit-manager.mit.edu" with "send tmp/hostinfo.shar" in the subject or body of the message. It'll only stay there for a week, though, so make sure to grab it. A couple notes: First of all, you should know that a site can have more than one IP address. The hostinfo program I mentioned above deals with that properly. Second, you should know that a host that looks like an internet site can have no IP addresses at all. Most of those are Mail eXchange, or MX, addresses, which means that when mailers ask the name servers, "How do I send mail to this host?" the name server responds with, "You send the mail to this other host instead, and it'll take care of final delivery of the mail." -- Jonathan Kamens USnail: MIT Project Athena 11 Ashford Terrace jik@Athena.MIT.EDU Allston, MA 02134 Office: 617-253-8085 Home: 617-782-0710