--- /dev/null
+
+PPP for Linux Version 0.2.8
+============= based on
+ ppp-2.1.0
+ May 1994
+
+Michael Callahan callahan@maths.ox.ac.uk
+Al Longyear longyear@netcom.com
+
+ Contents:
+ INTRODUCTION
+ CREDITS
+ FUTURE PLANS
+ INSTALLATION
+ GENERAL NETWORK CONFIGURATION
+ CONNECTING TO A PPP SERVER
+ IF IT WORKS
+ IF IT DOESN'T WORK
+ IF IT STILL DOESN'T WORK (OR, BUG REPORTS)
+ DYNAMIC ADDRESS ASSIGNMENT
+ SETTING UP A MACHINE FOR INCOMING PPP CONNECTIONS
+ ADDING MORE PPP CHANNELS
+ CHANGES FROM LINUX PPP 0.1.x
+ CONCLUSION
+
+
+INTRODUCTION
+
+This is a PPP driver for Linux. It has been used by many people and
+seems to be quite stable. It is capable of being used either as a
+'client'--for connecting a Linux machine to a local Internet provider,
+for example--or as a 'server'--allowing a Linux machine with a modem
+and an Ethernet connection to the Internet to provide dial-in PPP
+links. (In fact, the PPP protocol does not make the distinction
+between client and server, but this is the way people often think
+about it.)
+
+The PPP protocol consists of two parts. One is a scheme for framing
+and encoding packets, the other is a series of protocols called LCP,
+IPCP, UPAP and CHAP, for negotiating link options and for
+authentication. This package similarly consists of two parts: a
+kernel module which handles PPP's low-level framing protocol, and a
+user-level program called pppd which implements PPP's negotiation
+protocols.
+
+The kernel module assembles/disassembles PPP frames, handles error
+detection, and forwards packets between the serial port and either the
+kernel network code or the user-level program pppd. IP packets go
+directly to the kernel network code. So once pppd has negotiated the
+link, it in practice lies completely dormant until you want to take
+the link down, when it negotiates a graceful disconnect.
+
+CREDITS
+
+I (MJC) wrote the original kernel driver from scratch. Laurence
+Culhane and Fred van Kempen's slip.c was priceless as a model (a
+perusal of the files will reveal that I often mimicked what slip.c
+did). Otherwise I just implemented what pppd needs, using RFC1331 as
+a guide. For the most part, the Linux driver provides the same
+interface as the free 386BSD and SunOS drivers. The exception is that
+Linux has no support for asynchronous I/O, so I hacked an ioctl into
+the PPP kernel module that provides a signal when packets appear and
+made pppd use this instead.
+
+Al Longyear ported version 2.0.4 of pppd (from the free package
+ppp-2.0.4) to Linux. He also provided several enhancements to both
+the kernel driver and the OS-independent part of pppd. His
+contributions to Linux PPP have been immense, and so this release
+is being distributed over both our names.
+
+The pppd program comes from the free distribution of PPP for Suns and
+386BSD machines, maintained by Paul Mackerras. This package lists
+"thanks to" Brad Parker, Greg Christy, Drew D. Perkins, Rick Adams and
+Chris Torek.
+
+
+FUTURE PLANS
+
+The main missing feature is the ability to fire up a PPP connection
+automatically when a packet destined for the remote host is generated
+("demand-dialing"). Work is progressing on this, but it involves some
+nontrivial design issues.
+
+
+INSTALLATION
+
+This version of PPP has been tested on 1.0.x (x=0..9) and 1.1.x
+(x=0..14) kernels. It will probably not work on kernels much earlier
+than this due to a change in the routing code. If you have an earlier
+kernel, please upgrade.
+
+joining the PPP channel of linux-activists:
+
+ This isn't really part of installation, but if you DO use
+ Linux PPP you should do this. Send a message with the line
+ X-Mn-Admin: join PPP
+ contained in the body to linux-activists-request@niksula.hut.fi
+ You can send to the list by mailing to
+ linux-activists@niksula.hut.fi and putting the line
+ X-Mn-Key: PPP
+ at the start of your message.
+
+ The advantage of subscribing is that you'll be informed of
+ updates and patches, and you'll be able to draw on the
+ experience of many PPP users. If you have a problem, I may not
+ be able to diagnose it, but someone else may have solved it
+ already.
+
+ Note also that I do not read the linux Usenet newsgroups
+ regularly enough to catch any discussions of PPP; if you want to
+ reach the PPP audience you should join the linux-activists
+ channel.
+
+ To leave the PPP mailing list :-(, send a message with the line
+ X-Mn-Admin: leave PPP
+ to linux-activists-request.
+
+kernel driver installation:
+
+ This depends on the kernel version you're using.
+
+ Since 1.1.14, Linux kernels have had built-in support for PPP.
+ You'll be asked whether you want PPP when you run "make config".
+ It's as easy as that.
+
+ In 1.1.13, PPP is there but the PPP line in config.in is
+ commented out. If you have 1.1.13, you probably should just
+ upgrade anyway.
+
+ Kernel versions prior to 1.1.13 (including all 1.0.x kernels)
+ have had (hidden) support for PPP in the kernel configuration
+ setup for quite some time. Adding the PPP kernel driver is
+ easy:
+
+ 1) copy ppp.c from the linux subdirectory of the distribution
+ to drivers/net and ppp.h to include/linux
+ 2) uncomment the CONFIG_PPP line in config.in
+ 3) if you are using 1.1.3 or earlier (including 1.0.x):
+ uncomment the line in ppp.c that begins
+ /* #define NET02D
+ by removing the "/* " characters
+ 4) in the top level of the kernel source
+ make config
+ make dep
+ make
+
+ Reboot with the new kernel. At startup, you should see
+ something line this:
+
+ PPP: version 0.2.8 (4 channels)
+ TCP compression code copyright 1989 Regents of the University of California
+ PPP line discipline registered.
+
+ (If you want more than 4 channels, see the section "ADDING MORE
+ PPP CHANNELS" below.)
+
+ Now, try looking at the contents of /proc/net/dev. It should
+ look something like this:
+
+ Inter-| Receive | Transmit
+ face |packets errs drop fifo frame|packets errs drop fifo colls carrier
+ lo: 0 0 0 0 0 0 0 0 0 0 0
+ ppp0: 0 0 0 0 0 0 0 0 0 0 0
+ ppp1: 0 0 0 0 0 0 0 0 0 0 0
+ ppp2: 0 0 0 0 0 0 0 0 0 0 0
+ ppp3: 0 0 0 0 0 0 0 0 0 0 0
+
+ This indicates that the driver is successfully installed.
+
+ (Of course, you should keep a kernel without PPP around, in case
+ something goes wrong.)
+
+pppd installation:
+
+ First execute the following commands (in the ppp-2.2 directory):
+
+ ./configure
+ make
+
+ This will make the pppd and chat programs.
+
+ To install, type 'make install' (in the ppp-2.2 directory).
+ This will put chat and pppd binaries in /usr/etc
+ and the pppd.8 manual page in /usr/man/man8.
+
+ pppd needs to be run as root. You can either make it setuid
+ root or just use it when you are root. 'make install' will try
+ to install it setuid root. Making pppd setuid root is
+ convenient for a single-user machine, but has security
+ implications which you should investigate carefully before
+ making it available on a multiuser machine.
+
+GENERAL NETWORK CONFIGURATION
+
+Since many people don't use the Linux networking code at all until
+they get a PPP link, this section describes generally what's needed to
+get things running. In principle none of this is special to PPP. For
+more details, you should consult the relevant Linux HOWTOs. If you
+already understand network setup, you can skip this section.
+
+The first file that requires attention is the rc script that does
+network configuration at boot time, called /etc/rc.net or
+/etc/rc.d/rc.net.{1,2} or something similar, depending on your Linux
+distribution. This file should 'ifconfig' the loopback interface lo,
+and should add an interface route for it. These lines might look
+something like this:
+ $CONFIG lo 127.0.0.1
+ $ROUTE add loopback
+or
+ /sbin/ifconfig lo 127.0.0.1
+ /sbin/route add 127.0.0.1
+
+However, it should *not* config an ethernet card or install any other
+routes (unless you actually have an ethernet card, in which case I'll
+assume you know what to do). Many distributions will provide scripts
+that expect you to have an ethernet card.
+
+You also need to decide whether you want to allow incoming
+telnet/ftp/finger, etc. If so, you should have the rc startup script
+run the 'inetd' daemon.
+
+Next, you should set up /etc/hosts to have two lines. The first
+should just give the loopback or localhost address and the second
+should give your own host name and the IP address your PPP connection
+will use. For example:
+ 127.0.0.1 loopback localhost # useful aliases
+ 192.1.1.17 billpc.whitehouse.gov bill # my hostname
+where my IP address is 192.1.1.17 and my hostname is
+billpc.whitehouse.gov. (Not really, you understand.) If your PPP
+server does dynamic IP address assignment, give a guess as to an
+address you might get (see also "Dynamic Address Assignment" below).
+
+Finally, you need to configure the domain name system by putting
+appropriate lines in /etc/resolv.conf . It should look something like
+this:
+ domain whitehouse.gov
+ nameserver 192.1.2.1
+ nameserver 192.1.2.10
+Assuming there are nameservers at 192.1.2.1 and 192.1.2.10, then when
+you get connected with PPP, you can reach hosts whose full names are
+'hillarypc.whitehouse.gov' and 'chelseapc.whitehouse.gov' by the names
+'hillarypc' and 'chelseapc'. You can probably find out the right
+domain name to use and the IP numbers of nameservers from whoever's
+providing your PPP link.
+
+CONNECTING TO A PPP SERVER
+
+To use PPP, you invoke the pppd program with appropriate options.
+Everything you need to know is contained in the pppd(8) manual page.
+However, it's useful to see some examples:
+
+Example 1: A simple dial-up connection.
+
+Here's a command for connecting to a PPP server by modem.
+
+ pppd connect 'chat -v -f chat-script' \
+ /dev/cua1 38400 -detach debug crtscts modem defaultroute 192.1.1.17:
+
+where the file chat-script contains:
+
+ "" ATDT5551212 CONNECT "" ogin: ppp word: whitewater
+
+Going through pppd's options in order:
+ connect 'chat ...' This gives a command to run to contact the
+ PPP server. Here the supplied 'chat' program is used to dial a
+ remote computer. The whole command is enclosed in single quotes
+ because pppd expects a one-word argument for the 'connect' option.
+ The options to 'chat' itself are:
+ -v verbose mode; log what we do to syslog
+ -f chat-script expect-send strings are in the file chat-script
+ The strings for chat to look for and to send are stored in the
+ chat-script file. The strings can be put on the chat command line,
+ but this is not recommended because it makes your password visible
+ to anyone running ps while chat is running. The strings are:
+ "" don't wait for any prompt, but instead...
+ ATDT5551212 dial the modem, then
+ CONNECT wait for answer
+ "" send a return (null text followed by usual return)
+ ogin: ppp word: whitewater log in.
+ /dev/cua1 specify the callout serial port cua1
+ 38400 specify baud rate
+ -detach normally, pppd forks and puts itself in the background;
+ this option prevents this
+ debug log status in syslog
+ crtscts use hardware flow control between computer and modem
+ (at 38400 this is a must)
+ modem indicate that this is a modem device; pppd will hang up the
+ phone before and after making the call
+ defaultroute once the PPP link is established, make it the
+ default route; if you have a PPP link to the Internet this
+ is probably what you want
+ 192.1.1.17: this is a degenerate case of a general option
+ of the form x.x.x.x:y.y.y.y . Here x.x.x.x is the local IP
+ address and y.y.y.y is the IP address of the remote end of the
+ PPP connection. If this option is not specified, or if just
+ one side is specified, then x.x.x.x defaults to the IP address
+ associated with the local machine's hostname (in /etc/hosts),
+ and y.y.y.y is determined by the remote machine. So if this
+ example had been taken from the fictional machine 'billpc',
+ this option would actually be redundant.
+
+pppd will write error messages and debugging logs to the syslogd
+daemon using the facility name "daemon". (Verbose output from chat
+uses facility "local2".) These messages may already be logged to the
+console or to a file like /usr/adm/messages; consult your
+/etc/syslog.conf file to see. If you want to make all pppd and chat
+messages go to the console, add the line
+ daemon,local2.* /dev/console
+to syslog.conf; make sure to put one or more TAB characters between
+the two fields.
+
+Example 2: Connecting to PPP server over hard-wired link.
+
+This is a slightly more complicated example. This is the script I run
+to make my own PPP link, which is over a hard-wired Gandalf link to an
+Ultrix machine running Morningstar PPP.
+
+ pppd connect /etc/ppp/ppp-connect defaultroute noipdefault debug \
+ kdebug 2 /dev/cua0 9600
+
+Here /etc/ppp/ppp-connect is the following script:
+ #! /bin/sh
+ /etc/ppp/sendbreak
+ chat -v -t60 "" \; "service :" blackice ogin: callahan word: PASSWORD \
+ black% "stty -echo; ppp" "Starting PPP now" && sleep 5
+
+This sends a break to wake up my terminal server, sends a semicolon
+(which lets my terminal server do autobaud detection), then says we
+want the service "blackice". It logs in, waits for a shell prompt
+("black%"), then starts PPP. The -t60 argument sets the timeout to a
+minute, since things here are sometimes very slow. (Ideally the
+expect-send strings for chat should be in a file.)
+
+The "&& sleep 5" causes the script to pause for 5 seconds, unless chat
+fails in which case it exits immediately. This is just to give the
+PPP server time to start (it's very slow). Also, the "stty -echo"
+turned out to be very important for me; without it, my pppd would
+sometimes start to send negotiation packets before the remote PPP
+server had time to turn off echoing. The negotiation packets would
+then get sent back to my local machine, be rejected (PPP is able to
+detect loopback) and pppd would fail before the remote PPP server even
+got going. The "stty -echo" command prevents this confusion. This
+kind of problem should only ever affect a *very* few people who
+connect to a PPP server that runs as a command on a slow Unix machine,
+but I wanted to mention it because it took me several frustrating
+hours to figure out.
+
+The pppd options are mostly familiar. Two that are new are
+"noipdefault" and "kdebug 2". "noipdefault" tells pppd to ask the
+remote end for the IP address to use; this is necessary if the PPP
+server implements dynamic IP address assignment as mine does (i.e., I
+don't know what address I'll get ahead of time). "kdebug 2" sets the
+kernel debugging level to 2, enabling slightly chattier messages from
+the ppp kernel code.
+
+
+
+Anyway, assuming your connection is working, you should see chat dial
+the modem, then perhaps some messages from pppd (depending on your
+syslog.conf setup), then some kernel messages like this:
+
+ ppp: channel ppp0 mtu changed to 1500
+ ppp: channel ppp0 open
+ ppp: channel ppp0 going up for IP packets!
+
+(These messages will only appear if you gave the option "kdebug 2" and
+have kern.info messages directed to the screen.) Simultaneously, pppd
+is also writing interesting things to /usr/adm/messages (or other log
+file, depending on syslog.conf).
+
+IF IT WORKS
+
+If you think you've got a connection, there are a number of things you
+can do to test it.
+
+First, type
+ /sbin/ifconfig
+(ifconfig may live elsewhere, depending on your distribution.) This
+should show you all the network interfaces that are 'UP'. ppp0 should
+be one of them, and you should recognize the first IP address as your
+own and the "POINT-TO-POINT ADDR" as the address of your server.
+Here's what it looks like on my machine:
+
+lo Link encap Local Loopback
+ inet addr 127.0.0.1 Bcast 127.255.255.255 Mask 255.0.0.0
+ UP LOOPBACK RUNNING MTU 2000 Metric 1
+ RX packets 0 errors 0 dropped 0 overrun 0
+ TX packets 0 errors 0 dropped 0 overrun 0
+
+ppp0 Link encap Serial Line IP
+ inet addr 192.76.32.2 P-t-P 129.67.1.165 Mask 255.255.255.0
+ UP POINTOPOINT RUNNING MTU 1500 Metric 1
+ RX packets 33 errors 0 dropped 0 overrun 0
+ TX packets 42 errors 0 dropped 0 overrun 0
+
+Now, type
+ ping z.z.z.z
+where z.z.z.z is the address of your server. This should work.
+Here's what it looks like for me:
+ waddington:~$ ping 129.67.1.165
+ PING 129.67.1.165 (129.67.1.165): 56 data bytes
+ 64 bytes from 129.67.1.165: icmp_seq=0 ttl=255 time=268 ms
+ 64 bytes from 129.67.1.165: icmp_seq=1 ttl=255 time=247 ms
+ 64 bytes from 129.67.1.165: icmp_seq=2 ttl=255 time=266 ms
+ ^C
+ --- 129.67.1.165 ping statistics ---
+ 3 packets transmitted, 3 packets received, 0% packet loss
+ round-trip min/avg/max = 247/260/268 ms
+ waddington:~$
+
+Try typing:
+ netstat -nr
+This should show three routes, something like this:
+Kernel routing table
+Destination Gateway Genmask Flags Metric Ref Use Iface
+129.67.1.165 0.0.0.0 255.255.255.255 UH 0 0 6 ppp0
+127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
+0.0.0.0 129.67.1.165 0.0.0.0 UG 0 0 6298 ppp0
+
+If your output looks similar but doesn't have the destination 0.0.0.0
+line (which refers to the default route used for connections), you may
+have run pppd without the 'defaultroute' option.
+
+At this point you can try telnetting/ftping/fingering whereever you
+want, bearing in mind that you'll have to use numeric IP addresses
+unless you've set up your /etc/resolv.conf correctly.
+
+IF IT DOESN'T WORK
+
+If you don't seem to get a connection, the thing to do is to collect
+'debug' output from pppd. To do this, make sure you run pppd with the
+'debug' option, and put the following two lines in your
+/etc/syslog.conf file:
+ daemon,local2.* /dev/console
+ daemon,local2.* /usr/adm/ppplog
+This will cause pppd's messages to be written to the current virtual
+console and to the file /usr/adm/ppplog. Note that the left-hand
+field and the right-hand field must be separated by at least one TAB
+character. After modifying /etc/syslog.conf, you must execute the
+command 'kill -HUP <pid>' where <pid> is the process ID of the
+currently running syslogd process to cause it to re-read the
+configuration file.
+
+Some messages to look for:
+ - "pppd[NNN]: Connected..." means that the "connect" script has
+ completed successfully.
+ - "pppd[NNN]: sent [LCP ConfReq"... means that pppd has attempted to
+ begin negotiation with the remote end.
+ - "pppd[NNN]: recv [LCP ConfReq"... means that pppd has received a
+ negotiation frame from the remote end.
+ - "pppd[NNN]: ipcp up" means that pppd has reached the point where
+ it believes the link is ready for IP traffic to travel across it.
+
+If you never see a "recv" message then there may be serious problems
+with your link. (For example, the link may not be passing all 8
+bits.) If that's the case, it would be useful to collect a debug log
+which contains all the bytes being passed between your computer and
+the remote PPP server. To do this, alter your syslog.conf lines to
+look like this
+ local2.*,kern.* /dev/console
+ local2.*,kern.* /usr/adm/ppplog
+and HUP the syslog daemon as before. Then, run pppd with the option
+"kdebug 5". Whatever characters arrive over the PPP terminal line
+will appear in the debugging output.
+
+Occasionally you may see a message like
+ ppp_toss: tossing frame, reason = 4
+The PPP code is throwing away a packet ("frame") from the remote
+server because of a serial overrun. This means your CPU isn't able to
+read characters from the serial port as quickly as they arrive; the
+best solution is to get a 16550A serial chip, which gives the CPU some
+grace period. Reasons other than 4 indicate other kinds of serial
+errors, which should not occur.
+
+During the initial connection sequence, you may see one or more
+messages which indicate "bad fcs". This refers to a checksum error in
+a received PPP frame, and usually occurs at the start of a session
+when the peer system is sending some "text" messages, such as "hello
+this is the XYZ company". Messages of "bad fcs" once the link is
+established and the routes have been added are not normal and indicate
+transmssion errors or noise on the telephone line.
+
+IF IT STILL DOESN'T WORK (OR, BUG REPORTS)
+
+If you're still having difficulty, send the linux-activists PPP
+channel a bug report. It is extremely important to include as much
+information as possible; for example:
+ - the version number of the kernel you are using
+ - the version number of Linux PPP you are using
+ - the exact command you use to start the PPP session
+ - log output from a session run with the 'debug' option, captured
+ using local2.*,kern.* in your syslog.conf file
+ - the type of PPP peer that you are connecting to (eg, Xyzzy Corp
+ terminal server, Morningstar PPP software, etc)
+ - the kind of connection you use (modem, hardwired, etc...)
+
+DYNAMIC ADDRESS ASSIGNMENT
+
+You can use Linux PPP with a PPP server which assigns a different IP
+address every time you connect. You need to use the 'noipdefault'
+option to tell pppd to request the IP address from the remote host.
+
+Sometimes you may get an error message like "Cannot assign requested
+address" when you use a Linux client (for example, "talk"). This
+happens when the IP address given in /etc/hosts for our hostname
+differs from the IP address used by the PPP interface. The solution
+is to use ifconfig ppp0 to get the interface address and then edit
+/etc/hosts appropriately.
+
+SETTING UP A MACHINE FOR INCOMING PPP CONNECTIONS
+
+Suppose you want to permit another machine to call yours up and start
+a PPP session. This is possible using Linux PPP.
+
+One way is to create an account named, say, 'ppp', with the login
+shell being a short script that starts pppd. For example, the passwd
+entry might look like this:
+ ppp:(encrypted password):102:50:PPP client login:/tmp:/etc/ppp/ppplogin
+Here the file /etc/ppp/ppplogin would be an executable script
+containing something like:
+ #!/bin/sh
+ exec /usr/etc/pppd passive :192.1.2.23
+Here we will insist that the remote machine use IP address 192.1.2.23,
+while the local PPP interface will use the IP address associated with
+this machine's hostname in /etc/hosts. The 'passive' option (which is
+not required) just means that pppd will try to open negotiations when
+it starts, but if it receives no reply it will just wait silently.
+This is appropriate if the remote end might take some time before it's
+ready to negotiate. (Note that the meaning of the 'passive' option
+changed between ppp-1.3 and ppp-2.0.)
+
+This setup is sufficient if you just want to connect two machines so
+that they can talk to one another. If you want to use Linux PPP to
+connect a single machine to an entire network, or to connect two
+networks together, then you need to arrange for packets to be routed
+from the networks to the PPP link. Setting up a link between networks
+is beyond the scope of this document; you should examine the routing
+options in the manual page for pppd carefully and find out about
+routed, etc.
+
+Let's consider just the first case. Suppose you have a Linux machine
+attached to an Ethernet, and you want to allow its PPP peer to be able
+to communicate with hosts on that Ethernet. To do this, you should
+have the remote machine use an IP address that would normally appear
+to be on the local Ethernet segment and you should give the 'proxyarp'
+option to pppd on the server. Suppose, for example, we have this
+setup:
+
+ 192.1.2.23 192.1.2.17
++-----------+ PPP link +----------+
+| chelseapc | ------------------- | billpc |
++-----------+ +----------+
+ | Ethernet
+ ----------------------------------- 192.1.2.x
+
+Here the PPP and Ethernet interfaces of billpc will have IP address
+192.1.2.17. (It's OK for one or more PPP interfaces on a machine to
+share an IP address with an Ethernet interface.) There is an
+appropriate entry in /etc/passwd on billpc to allow chelseapc to call
+in, with the /etc/ppp/ppplogin script containing
+ #!/bin/sh
+ exec /usr/etc/pppd passive proxyarp :192.1.2.23
+When the link comes up, pppd will enter a "proxy arp" entry for
+chelseapc into the arp table on billpc. What this means effectively
+is that billpc will pretend to the other machines on the 192.1.2.x
+Ethernet that its Ethernet interface is ALSO the interface for
+chelseapc (192.1.2.23) as well as billpc (192.1.2.17). In practice
+this means that chelseapc can communicate just as if it was directly
+connected to the Ethernet.
+
+ADDING MORE PPP CHANNELS
+
+By default, Linux PPP comes with 4 kernel channels, which means that
+at most 4 simultaneous PPP sessions are possible. If you desire more
+such sessions (for example if you are serving many dialup lines), you
+can easily reconfigure the kernel to add new channels. There are two
+steps.
+
+First you need to edit the kernel file drivers/net/Space.c . As
+distributed, it contains a section that looks like this:
+
+#if defined(CONFIG_PPP)
+extern int ppp_init(struct device *);
+static struct device ppp3_dev = {
+ "ppp3", 0x0, 0x0, 0x0, 0x0, 3, 0, 0, 0, 0, NEXT_DEV, ppp_init, };
+static struct device ppp2_dev = {
+ "ppp2", 0x0, 0x0, 0x0, 0x0, 2, 0, 0, 0, 0, &ppp3_dev, ppp_init, };
+static struct device ppp1_dev = {
+ "ppp1", 0x0, 0x0, 0x0, 0x0, 1, 0, 0, 0, 0, &ppp2_dev, ppp_init, };
+static struct device ppp0_dev = {
+ "ppp0", 0x0, 0x0, 0x0, 0x0, 0, 0, 0, 0, 0, &ppp1_dev, ppp_init, };
+#undef NEXT_DEV
+#define NEXT_DEV (&ppp0_dev)
+#endif /* PPP */
+
+The pattern should be obvious. For more channels, you need to add
+more "static struct device pppN_dev" lines, changing the first, sixth
+and eleventh structure entries as appropriate. The highest numbered
+PPP device should have NEXT_DEV in its eleventh structure field, and
+you should change the ppp3_dev structure to have &ppp4_dev there
+instead.
+
+For example, to add 2 extra channels, you would have
+
+#if defined(CONFIG_PPP)
+extern int ppp_init(struct device *);
+static struct device ppp5_dev = {
+ "ppp5", 0x0, 0x0, 0x0, 0x0, 5, 0, 0, 0, 0, NEXT_DEV, ppp_init, };
+static struct device ppp4_dev = {
+ "ppp4", 0x0, 0x0, 0x0, 0x0, 4, 0, 0, 0, 0, &ppp5_dev, ppp_init, };
+static struct device ppp3_dev = {
+ "ppp3", 0x0, 0x0, 0x0, 0x0, 3, 0, 0, 0, 0, &ppp4_dev, ppp_init, };
+... etc.
+
+Second, you need to change the line in ppp.h (in include/linux) to
+change the line that reads
+
+#define PPP_NRUNIT 4
+
+to show the new number of channels; in our case it would become
+
+#define PPP_NRUNIT 6
+
+Finally, recompile and reboot. The bootup message and the contents of
+/proc/net/dev should show the correct number of channels.
+
+CHANGES FROM LINUX PPP 0.1.x
+
+Linux PPP 0.1.x was based on the free PPP package PPP-1.3. Linux PPP
+0.2.1 is based on PPP-2.0.4. There have been some changes to the pppd
+options along with significant enhancements. You should read
+"RELNOTES" in the pppd directory for a description of the changes.
+
+Also, some options which were added to PPP-1.3 for the Linux version
+have now changed names:
+ 'defroute' is now 'defaultroute'
+ 'kerndebug' is now 'kdebug'
+ 'dropdtr' is now 'modem'
+In addition, it is now necessary to use the 'noipdefault' option if
+you want to get the local IP address from the remote PPP server.
+
+CONCLUSION
+
+Good luck!
+
+Michael
projects / ppp.git / blobdiff