Wireshark · Ethereal-users: Re: [Ethereal-users] Does it also make coffee?

[Guy Harris <guy@xxxxxxxxxx>]

On Tue, Feb 26, 2002 at 04:32:34PM -0600, Keith G. Murphy wrote:
> It comes up with the correct host names, without me having to do
> anything.  (Must be looking at NetBIOS, as well as DNS).

Ethereal doesn't itself look at either of them - it just calls the
"gethostbyaddr()" routine on the OS on which it's running.  On Windows,
that routine attempts to look up host names using NetBIOS, as well as
DNS; sometimes that's nice, and sometimes it's an irritation
(translating IP addresses to NetBIOS names involves sending to the IP
address a NetBIOS message and waiting either for

	1) the machine to reply

or

	2) no reply to come back within a timeout period

and the timeout period is a bit long, so if there *is* no DNS entry for
the IP address, and if NetBIOS isn't running on the machine with that IP
address, it may take a significant period of time for "gethostbyaddr()"
- whether it's Ethereal, or some other program, calling it - to return a
"sorry, I don't know the host name" indication).