Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!decvax!decwrl!ucbvax!RED.RUTGERS.EDU!HEDRICK From: HEDRICK@RED.RUTGERS.EDU.UUCP Newsgroups: mod.protocols.tcp-ip Subject: more interesting features of 4.2 Message-ID: <12211785351.33.HEDRICK@RED.RUTGERS.EDU> Date: Tue, 3-Jun-86 02:20:26 EDT Article-I.D.: RED.12211785351.33.HEDRICK Posted: Tue Jun 3 02:20:26 1986 Date-Received: Tue, 3-Jun-86 21:52:14 EDT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The ARPA Internet Lines: 31 Approved: tcp-ip@sri-nic.arpa I have finally found a mechanism that seems to work for getting Suns to route automatically. It turns out that you can specify routing entries that will cause a host to treat destinations on that network as local. I.e. it will issue ARP's for them, just as if they were on the local Ethernet. The correct form is route add 0 if you want to set this up as a default. It turns out that all of our diskless Sun 3's come up with such a default address automatically. We believe that this is due to a bug, but it is a fairly happy one, from my point of view. I have modified our gateway software to be able to handle a network where the hosts issue ARP's for everyone. The gateway responds to ARPs for hosts on the other side of the gateway. It also responds to ARPs for hosts on the other side of gateways that don't know about the convention (giving their Ethernet address, of course, not its own -- this is an ARP-level equivalent of an ICMP redirect). This strategy has a number of advantages from my point of view: - it requires no action on the part of the user, at least until Sun fixes their bug, if it is one. - the entry need not have wired-in knowledge of the gateway's address. If we change gateway configurations, this will continue to work. - if we have more than one gateway, and they talk to each other, we can take advantage of their redundancy, since we don't have specific routings built into the table. I'm sure the gateway committee will come up with a more elegant way to do things, but this looks like the best alternative to the problem I have been posing for some time. It involves no modification to Unix, does not depend upon hosts failing to validate ICMP redirects, etc. -------