Re: Dynamically Assigned IPs

Bill Woodland (wcw@bga.com)
Mon, 24 Feb 1997 22:21:30 -0600


At 09:59 AM 2/24/97 -0500, you wrote:
>I have both the White Pine and Cornell versions of the cuseeme software.
>I would like to use the Cornell version more before investing in White
>Pine to avoid the time-out problem. However, I seem to recall reading
>that the Cornell version requires a file be present at boot-up which
>contains, among other things, the IP address of the user machine. =20
>
>My ISP assigns IP addresses dynamically which would mean, as I
>understand it, my IP address could and probably would change each time I
>boot the system. How then can I create the file needed by the Cornell
>cuseeme program if I must then reboot for the program to recognize the
>IP address which, by virtue of the re-boot would likely have changed? =20
>Is the logic here correct or has something escaped me?
>
>Tom
>
>

Thanks to Mark L Bardenwerper for the kind "plug". Let me give you a short
answer, tho:

The short answer is that MOST people don't need one. If your ISP hasn't
setup a Reverse DNS, or if you are on a LAN and there is no host file setup
by the LAN administrator, then you will need one. Look at this line from
the header of your email message:

Received: from default (dyn126.usaor.net [206.148.135.126]) by=
gate.usaor.net=20

When you dialed in, you were assigned the IP address of 206.148.135.126,
which resolves to the name of dyn126.usaor.net and I used wshost to test the
name lookup from that IP, and vice versa. Both worked, which tells me that
your ISP has a reverse DNS setup, and you don't need a hosts file at all.

If you want to try this for yourself, just email yourself a message and look
at the header info. If you would like more info on this, refer to the
"GetHostName() Error Help" section on my web page.

Bill Woodland (Squeek =A9)
Email, PowWow, and ICQ: wcw@bga.com
URL:http://cu-seeme.cornell.edu/~WCW
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