	PPP (Point-to-Point Procotol) Installation

1. Implementation Notes.

	ppp is intended replace Sun's ptp and runs on top of zss.  You will
	need to install the SunLink Internetwork Router except for the parts
	that pertain to ptp.

	Only the maximum receive unit LCP configuration option and compression
        type IPCP configuration option are supported for values other than the
	defaults. 

	This program does not yet support authentication, encryption,
	magic numbers, link quality monitoring, protocol field compression,
	address and control field compression or IP address negotiation.

	This program does support Van Jacobson Compressed TCP/IP.


2. Configuring the KERNEL.

	a) Put the following files in the directory /usr/sys/sunif.

		if_ppp.c
		slcompress.c
		slcompress.h


	b) Edit the file /usr/sys/sun4c/conf/files. Adding the following
	   line.

		sunif/if_ppp.c		optional ppp
		slcompress.c		optional ppp


	c) Edit the configuration file /usr/sys/sun4c/conf/HOSTNAME.  Adding
	   the following line.
	
		pseudo-device	ppp2 init ppp_init


	d) Make the new kernel. 

		# cd /usr/sys/sun4c/conf
		# config HOSTNAME
		# cd ../HOSTNAME
		# make


	e) Save the old kernel under a different name.

		# mv /vmunix /vmunix-
		

	f) Install the new kernel.

		# cp /usr/sys/sun4c/HOSTNAME/vmunix /vmunix


	g) Boot the new kernel.

		# halt
		>b vmunix


3. Configuring the PPP interface.

	a) Initialize the Port.

		# syncinit zss0 speed=19200 txc=txc rxc=rxc


	b) Establish Layering.

		# iflayer ppp0 zss0


	c) Turn on Van Jacobson TCP/IP compression.

		# pppconfig ppp0 +0x4000 

	   (pppconfig ppp0 -0x4000 turns off Van Jacabson TCP/IP compression.)
		

	d) Associate ppp Devices and Hosts.

		# ifconfig ppp0 inet 128.171.6.1 128.171.6.2 netmask 0xffffff00 up


	e) Check Protocol Status.

		# ifconfig ppp0

		ppp0: flags=c051<UP,POINTOPOINT,RUNNING,PRIVATE>
			inet 128.171.6.2 --> 128.171.6.1 netmask ffffff00 

	   If the words UP and RUNNING are displayed, the connection is intact.


	f) Check Network Addresses.

		# netstat -i

		Name  Mtu   Net/Dest    Address      Ipkts   Ierrs Opkts   Oerrs
		ie0   1500  128.171.1.  ceta         78802   0     53927   0    
		ppp0  4096  128.171.6.  128.171.6.2  141474  0     146594  0    
		lo0   1536  loopback    localhost    314     0     314     0    

	The link may be brought up automatically on reboot by putting steps a)
	through d) in /etc/rc.local.
