Re: It's Alive

[Barry Margolin <barmar@THINK.COM>]

    Date: Thu, 21 Sep 89 16:25:41 EST
    From: bouma@cs.purdue.edu

    The symbolics' must keep trying to contact the gateway to see
    if it has come up. Why don't they just wait until I try sending something
    through the gateway?

The list you see in Peek is the Lispm's list of DEFAULT gateways.  When
you try to send something to a subnet that you've never used before, the
Lispm must choose one of the default gateways.  In order to narrow the
choice down to gateways that it believes are up, it periodically "pings"
all of them.  By doing this it doesn't have to waste your time by
pinging the gateways when you try sending something (the timeout is a
couple of seconds, so if there are several down gateways it could be a
long delay).

It's only one packet a minute per Lispm per gateway, not really that
much overhead.  Unix rwho is about the same overhead.

    Thanks for everyone's input. When does 7.4 get released?

7.4 was released early this year, but only for Ivory machines.  7.5 is
supposed to be released this winter.

                                                barmar