Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!decvax!decwrl!ucbvax!YALE.ARPA!LEICHTER-JERRY From: LEICHTER-JERRY@YALE.ARPA.UUCP Newsgroups: mod.computers.vax Subject: Re: DECnet information thru System Service calls Message-ID: <8606051000.AA08698@ucbvax.Berkeley.EDU> Date: Thu, 5-Jun-86 06:00:49 EDT Article-I.D.: ucbvax.8606051000.AA08698 Posted: Thu Jun 5 06:00:49 1986 Date-Received: Thu, 5-Jun-86 20:42:16 EDT Sender: daemon@ucbvax.BERKELEY.EDU Reply-To: Organization: The ARPA Internet Lines: 19 Approved: info-vax@sri-kl.arpa Does any one know the system service call.... Mark H. Granoff (mhg@mitre-bedford) There is no way to do this, at present. (In general, a node doesn't even KNOW what other nodes are reachable - non-routing nodes almost never know, and even routers know only about their own areas and - for area routers - other routers.) The quickest known approach is to use the following hack: Choose and reserve some DECnet object number, say 123. NEVER define an object numbered 123. The, to determine if node FOO is reachable, try to connect to FOO::"TASK=123". This will always fail, but a check of the error returned will tell you why. (The reason for using the non-existent object number hack is that it avoids ever creating a process on the remote system if you DO manage to reach it.) -- Jerry -------