NETWORK@FRSAC11.BITNET (12/21/88)
I would like opinions and informations on the following problem : We have a large research campus, with potentially several thousands of connected computers (PC, workstations and mainframes). There is three main protocols to be run over Ethernet : TCP/IP, XNS and DECNet. (We run SNA, X25 and Hyperchannel, too) Currently there are some Fiber Optic links from the various buildings, to a passive star located in the Telecom unit. (We use Codenoll Fiber Optic transceiver (3310/3311) and 3Com Multiconnect star) Each Ethernet is linked to the star through a filter/repeater, to make an Extended Ethernet. (We use Micom IB30) The evolution is going toward a FDDI backbone, but in the mean time we need to have the network running. Now the questions : Is it reasonable to do a single network carrying the 3 protocols, i.e. a level 2 network ? (By level 2 I mean MAC level Ethernet frames, thus not building the network with IP gateways between subnets, and with mixing of the 3 protocols on the same media) Or is it better to do 3 parallel networks ? (DECnet is not so widespread, but may become so, and XNS is used only by the PCs doing administrativia, under 3Com system) (The PC networks were planned to exchange informations through X25 gateways, low level traffic, integrated into the general X25 net.) What kind of trouble can we expect from a level 2 network ? (For IP we would use a single class B network) Are the IB30 enough to isolate Ethernets from wild computers going bezerk on their network ? (We have the case of a uVax Ultrix making 3 suns crazy with burst of broadcast ARP packets, playing ping-pong, and literally stopping the sun 2/260 for several seconds every minute or so... a generalisation of this will can make the network unusable quite fast) Why all University campus network scheme I have seen do not seems to mix protocols ? The other possibility is to make a IP only network, with gateways between subnets. (what kind of hardware can we use as gateway is an other questions : PCs with the proper software and some Ethernet controler cards, or Suns with more than two Ethernet controller cards, or ...?) Is there any way to make a single physical gateway do the routing for the 3 protocols simultaneoulsly ? The latest, and more theoretical, question : Is it possible to have a class C network used as intermediate between subnets of a single class B network ? regards, Jean-Pierre H. Dumas network@frsac11 (bitnet) network%frsac11.bitnet@cunyvm.cuny.edu (arpanet) dumas@sumex-aim.stanford.edu (arpanet)
D1DSK@AKRONVM.BITNET (Debbie Keller) (12/28/88)
We are running XNS, DECnet, and TCP/IP simultaniously using a Proteon P4200 gateway. We have note had any trouble with it. Ohio State is using the same setup and also don't have any trouble. We are both using Proteon for our backbone, with Ethernet gateways, but this is not neccessary.