New Network System -- Problems to be solved

- Multiple Processors & network interfaces

	A backplane can have from 1 to 3 Lambda processors.  It can also have a
	3com board and/or an Excelan board (or neither).

	Desired Action:

	A single Lambda system with just an Excelan or just a 3com: works fine
	already.

	A single Lambda system with both Excelan and 3com: configures itself to
	use only the 3com *** Should configure itself to use both if more than
	one Chaos and/or Internet address is known for this system (gateway
	functions.)  If only one Chaos or Internet address is known, the Lambda
	is presumably only on one network, and doesn't really need more than one
	interface.

	Multiple Lambda system with just a 3com or an Excelan: works fine until
	ethernet owner crashes.  *** One of the other processors should then
	take over the card.

	Multiple Lambda system with both Excelan and 3com, the first processor
	takes the 3com, the second the Excelan, and the third accesses the
	network through the 3com owner.  *** If that processor crashes, should
	switch to Excelan owner or take over 3com card.

- Multiple Processors & share device.

	There are a few kludges wherein the SHARE device is explicitly known as
	the interface to other processors on the same bus.

	    arp.lisp: net:processor-without-network-interface determines if a
		network address is owned by a processor on the same bus with no
		network interface.  Currently looks specifically at
		ethernet:*3com-owner* and ethernet:*excelan-owner* arp.lisp:
		net:addr-res-packet-for-me-p uses this to determine if this
		processor should respond to ARP packets for that address

	    chsncp.lisp: chaos:transmit-int-pkt sends to
		hardware controller if not this processor

	    ip.lisp: ip:initialize-route-table sets up hardware
		controller as default gateway

- Site Configuration

	Default gateways must be listed including protocols forwarded by them:
		(:gateways ("aza" :internet :chaos)
			   ("lad" :internet :chaos))

		<AZA:> (:internet 192.1.2.2 192.2.3.12) (:chaos 6.9 7.12)
		<LAD:> (:internet 192.1.2.6 10.4.0.191) (:chaos 6.5)

	Thus: if a host knows it is on net 192.1.2.0, it has two gateways to
	pick from:
		AZA goes to 192.2.3.0 and LAD goes to 10.0.0.0

	The host will initialize its routing tables with this information.
	Either gateway can be used as a default for other networks;
	    if the default gateway goes down, the other gateway should be used
	    as the default gateway.

- Point to point links, serial lines, modems, etc.

- IP fixes
	ip: properly deal with ip-self-address (all zeros in host field).
	    This is needed to make ICMP info request work.

- ICMP fixes
	icmp: update routing-table when receive (net, host) unreachable
	icmp: log received parameter problem messages

- TCP fixes
     ***Proper window management -- receiver's silly window syndrome
	    fix, better delayed acks, etc.
 	TCP receives destination unreachable, time exceeded, and source quench
	    messages from ICMP.  Currently it passes them all to the user.
	    Some of them (Source quench?) should be handled by TCP itself.
	"It is a bad idea to delay an ACK more than 1/2 median
	    inter-packet-arrival-time"
	Tuning -- speed up algorithms, minimize packets
	:write-data has :start and :end keywords

- Loopback interface
	damage, delay, drop, duplicate