Path: utzoo!mnetor!uunet!lll-winken!lll-tis!ames!pasteur!ucbvax!SPAM.ISTC.SRI.COM!robert
From: robert@SPAM.ISTC.SRI.COM (Robert Allen)
Newsgroups: comp.protocols.tcp-ip
Subject: 4.3 TCP sockets revisited.
Message-ID: <8804192115.AA16635@milk10>
Date: 19 Apr 88 21:15:36 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 38


    Last year I asked some questions about TCP sockets under 4.2-4.3BSD
    UNIX, concerning a dynamic alternate routing capability.  Specifically
    I was concerned that under 4.2 routes are closely tied to the TCP
    sockets using that route, such that if the route dies then the TCP peers
    at the sockets also time out and die, forcing the application using
    the sockets to restart the sockets.  Rumor had it that 4.3 would solve
    some of these problems, because the TCP timers could last long enough
    for a new route to be obtained.  The part of the problem which was perhaps
    not addressed under 4.3 was the caching of only a single 'good' route at
    a time.

    Now I have heard that the Sun Internetwork Router (based on XNS) under
    the newer versions of SunOS supports load sharing, which leads me to
    believe that Sun must also support redundant routes in the routing tables.
    I have a need for highly responsive route switching under the socket layer
    in the work I'm doing, where the physical layer tends to be poor or non-
    existant on a per-route basis over time.  If the functionality has not been
    implemented yet I have an interest in trying it myself, but I don't want
    to re-invent the wheel, Sooo...

    My questions are:

	(a) Has Sun implemented what I call here "dynamic redundant routing"?
	    If so, under which releases of the OS?
	    If so, is it only for the Internetwork Router?

	(b) If Sun has not implemented it, has Berkeley, or someone else?

	(c) If Sun has not implemented it, how are they doing load sharing
	    over the I.R.?  Did I hear a wrong rumor?


    Please call, write or post to the net. 

    Thanks,

    Robert Allen,
    robert@spam.istc.sri.com	415-859-2143