bzs@bu-cs.UUCP (10/12/87)
From: george@tut.cis.ohio-state.edu (George Jones) >Does anyone know if it is possible to do subnetting with the software >provided with UMAX 4.2 R2.1.2 (or any later release that I don't know >about yet) Thus far none of the Umax releases support subnetting, they have indicated to us that it is forthcoming "real soon now". The real question is, what do you mean by "do subnetting". For example, we are subnetted here at BU across all networks and the four Multimaxes are surviving while waiting for more support. One important point is that none of the Multimaxes act as gateways (all use exactly one ethernet interface) which reduces one sort of demand. The other demand is routing to other parts of the subnet that need to be directed at gateways. I am using a proxy arp daemon I wrote for the Sun to assist with this, I could make the (3.4) binary available (it's based on Sun's rarpd so I couldn't distribute sources, it's also tied to the Sun by its use of their NIT protocol, basically you need some way to multiplex/demultiplex broadcast packets from the applications level.) Even without this you could at least get to the local subnet, but that might not be satisfactory (perfectly reasonable need.) The only problem I've seen is that the Encore (as well as other machines we have who are not up to subnetting) will arp at some rate for things like broadcast addresses (see, they think that an address like 128.197.2.0 is a HOST address), some of this sort of excess arping can be minimized by setting the kernel variable ip_forwarding to zero instead of it's default value of one (can be done with adb -w on the binary easily, can not be done if the system uses more than one interface and acts as a gateway, this is what ip_forwarding is for.) Anyhow, depending on your model and available resources you either have no problem at all or are totally sunk (until Encore releases a subnet version of the kernel, which I hope is soon.) -Barry Shein, Boston University