[ILUG] Network programming question....

[Stephen Shirley]

Mornin' all,
	Here's the problem. I had a linux box (A), and a sun box (B). They
	are both connected to a 100mb switched private lan. They are the
	only boxen on this network. I have complete control over A, but none
	over B. I need to be able to write a program to run on A that will
	detect as fast as possible if B is up or down. Calling ping or any
	other external programs is out of the question - too much overhead.
	This might have to be done many times a second. My initial idea was
	to open a tcp connection to a port i know is closed on B, thereby
	getting a REJECT, and confirming it's up. This solution takes on
	average 509 usecs to say yay, and times out after 500 msecs
	(configurable) to say nay. 

	Now it's been suggested that I try some facny tcp half-connect
	modes, or maybe even arp. However, networks aren't my speciality. I
	was wondering if anyone had any suggestions/comments.

TIA,
Steve
P.s. I know that this is not strictly a linux question, but this is a
linux _users_ list, and i'm doing this using linux.
-- 
"My mom had Windows at work and it hurt her eyes real bad"