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diff --git a/mdk-stage1/ppp/README.linux b/mdk-stage1/ppp/README.linux new file mode 100644 index 000000000..62ed9ca7f --- /dev/null +++ b/mdk-stage1/ppp/README.linux @@ -0,0 +1,297 @@ + PPP for Linux + ------------- + + Paul Mackerras + 8 March 2001 + + for ppp-2.4.1 + +1. Introduction +--------------- + +The Linux PPP implementation includes both kernel and user-level +parts. This package contains the user-level part, which consists of +the PPP daemon (pppd) and associated utilities. In the past this +package has contained updated kernel drivers. This is no longer +necessary, as the current 2.2 and 2.4 kernel sources contain +up-to-date drivers. + +The Linux PPP implementation is capable of being used both for +initiating PPP connections (as a `client') or for handling incoming +PPP connections (as a `server'). Note that this is an operational +distinction, based on how the connection is created, rather than a +distinction that is made in the PPP protocols themselves. + +Mostly this package is used for PPP connections over modems connected +via asynchronous serial ports, so this guide concentrates on this +situation. + +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, PAP 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. + + +2. Installation +--------------- + +2.1 Kernel driver + +Assuming you are running a recent 2.2 or 2.4 (or later) series kernel, +the kernel source code will contain an up-to-date kernel PPP driver. +If the PPP driver was included in your kernel configuration when your +kernel was built, then you only need to install the user-level +programs. Otherwise you will need to get the source tree for your +kernel version, configure it with PPP included, and recompile. Most +Linux distribution vendors ship kernels with PPP included in the +configuration. + +The PPP driver can be either compiled into the kernel or compiled as a +kernel module. If it is compiled into the kernel, the PPP driver is +included in the kernel image which is loaded at boot time. If it is +compiled as a module, the PPP driver is present in one or more files +under /lib/modules and is loaded into the kernel when needed. + +The 2.2 series kernels contain an older version of the kernel PPP +driver, one which doesn't support multilink. If you want multilink, +you need to run the latest 2.4 series kernel. The kernel PPP driver +was completely rewritten for the 2.4 series kernels to support +multilink and to allow it to operate over diverse kinds of +communication medium (the 2.2 driver only operates over serial ports +and devices which look like serial ports, such as pseudo-ttys). + +Under the 2.2 kernels, if PPP is compiled as a module, the PPP driver +modules should be present in the /lib/modules/`uname -r`/net directory +(where `uname -r` represents the kernel version number). The PPP +driver module itself is called ppp.o, and there will usually be +compression modules there, ppp_deflate.o and bsd_comp.o, as well as +slhc.o, which handles TCP/IP header compression. If the PPP driver is +compiled into the kernel, the compression code will still be compiled +as modules, for kernels before 2.2.17pre12. For 2.2.17pre12 and later, +if the PPP driver is compiled in, the compression code will also. + +Under the 2.4 kernels, there are two PPP modules, ppp_generic.o and +ppp_async.o, plus the compression modules (ppp_deflate.o, bsd_comp.o +and slhc.o). If the PPP generic driver is compiled into the kernel, +the other four can then be present either as modules or compiled into +the kernel. There is a sixth module, ppp_synctty.o, which is used for +synchronous tty devices such as high-speed WAN adaptors. + + +2.2 User-level programs + +If you obtained this package in .rpm or .deb format, you simply follow +the usual procedure for installing the package. + +If you are using the .tar.gz form of this package, then cd into the +ppp-2.4.1b1 directory you obtained by unpacking the archive and issue +the following commands: + +$ ./configure +$ make +# make install + +The `make install' has to be done as root. This makes and installs +four programs and their man pages: pppd, chat, pppstats and pppdump. +If the /etc/ppp configuration directory doesn't exist, the `make +install' step will create it and install some default configuration +files. + + +2.3 System setup for 2.4 kernels + +Under the 2.4 series kernels, pppd needs to be able to open /dev/ppp, +character device (108,0). If you are using devfs (the device +filesystem), the /dev/ppp node will automagically appear when the +ppp_generic module is loaded, or at startup if ppp_generic is compiled +in. + +If you have ppp_generic as a module, and you are using devfsd (the +devfs daemon), you will need to add a line like this to your +/etc/devfsd.conf: + +LOOKUP ppp MODLOAD + +Otherwise you will need to create a /dev/ppp device node with the +commands: + +# mknod /dev/ppp c 108 0 +# chmod 600 /dev/ppp + +If you use module autoloading and have PPP as a module, you will need +to add the following to your /etc/modules.conf or /etc/conf.modules: + +alias /dev/ppp ppp_generic +alias char-major-108 ppp_generic +alias tty-ldisc-3 ppp_async +alias tty-ldisc-14 ppp_synctty +alias ppp-compress-21 bsd_comp +alias ppp-compress-24 ppp_deflate +alias ppp-compress-26 ppp_deflate + + +2.4 System setup under 2.2 series kernels + +Under the 2.2 series kernels, you should add the following to your +/etc/modules.conf or /etc/conf.modules: + +alias tty-ldisc-3 ppp +alias ppp-compress-21 bsd_comp +alias ppp-compress-24 ppp_deflate +alias ppp-compress-26 ppp_deflate + + +3. Getting help with problems +----------------------------- + +If you have problems with your PPP setup, or you just want to ask some +questions, or better yet if you can help others with their PPP +questions, then you should join the linux-ppp mailing list. Send an +email to majordomo@vger.kernel.org with a line in the body saying + +subscribe linux-ppp + +To leave the mailing list, send an email to majordomo@vger.kernel.org +with a line in the body saying + +unsubscribe linux-ppp + +To send a message to the list, email it to linux-ppp@vger.kernel.org. +You don't have to be subscribed to send messages to the list. + +You can also email me (paulus@linuxcare.com.au) but I am overloaded +with email and I can't respond to most messages I get in a timely +fashion. + +There are also several relevant news groups, such as comp.protocols.ppp, +comp.os.linux.networking, or comp.os.linux.setup. + + +4. Configuring your dial-out PPP connections +-------------------------------------------- + +Some Linux distribution makers include tools in their distributions +for setting up PPP connections. For example, for Red Hat Linux and +derivatives, you should probably use linuxconf or netcfg to set up +your PPP connections. + +The two main windowing environments for Linux, KDE and Gnome, both +come with GUI utilities for configuring and controlling PPP dial-out +connections. They are convenient and relatively easy to configure. + +A third alternative is to use a PPP front-end package such as wvdial +or ezppp. These also will handle most of the details of talking to +the modem and setting up the PPP connection for you. + +Assuming that you don't want to use any of these tools, you want to +set up the configuration manually yourself, then read on. This +document gives a brief description and example. More details can be +found by reading the pppd and chat man pages and the PPP-HOWTO. + +We assume that you have a modem that uses the Hayes-compatible AT +command set connected to an async serial port (e.g. /dev/ttyS0) and +that you are dialling out to an ISP. + +The trickiest and most variable part of setting up a dial-out PPP +connection is the part which involves getting the modem to dial and +then invoking PPP service at the far end. Generally, once both ends +are talking PPP the rest is relatively straightforward. + +Now in fact pppd doesn't know anything about how to get modems to dial +or what you have to say to the system at the far end to get it to talk +PPP. That's handled by an external program such as chat, specified +with the connect option to pppd. Chat takes a series of strings to +expect from the modem interleaved with a series of strings to send to +the modem. See the chat man page for more information. Here is a +simple example for connecting to an ISP, assuming that the ISP's +system starts talking PPP as soon as it answers the phone: + +pppd connect 'chat -v "" AT OK ATDT5551212 ~' \ + /dev/ttyS0 57600 crtscts debug defaultroute + +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 + "" don't wait for any prompt, but instead... + AT send the string "AT" + OK expect the response "OK", then + ATDT5551212 dial the modem, then + ~ wait for a ~ character, indicating the start + of a PPP frame from the server + + /dev/ttyS0 specifies which serial port the modem is connected to + 57600 specifies the baud rate to use + crtscts use hardware flow control using the RTS & CTS signals + debug log the PPP negotiation with syslog + defaultroute add default network route via the PPP link + +Pppd will write error messages and debugging logs to the syslogd +daemon using the facility name "daemon". These messages may already +be logged to the console or to a file like /var/log/messages; consult +your /etc/syslog.conf file to see. If you want to make all pppd +messages go to a file such as /var/log/ppp-debug, add the line + +daemon.* /var/log/ppp-debug + ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + This is one or more tabs. Do not use spaces. + +to syslog.conf; make sure to put one or more TAB characters (not +spaces!) between the two fields. Then you need to create an empty +/var/log/ppp-debug file with a command such as + + touch /var/log/ppp-debug + +and then restart syslogd, usually by sending it a SIGHUP signal with a +command like this: + + killall -HUP syslogd + + +4.1 Is the link up? + +The main way to tell if your PPP link is up and operational is the +ifconfig ("interface configuration") command. Type + + /sbin/ifconfig + +at a shell prompt. It should print a list of interfaces including one +like this example: + +ppp0 Link encap Point-to-Point Protocol + inet addr 192.76.32.3 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 + +Assuming that ifconfig shows the ppp network interface, you can test +the link using the ping command like this: + + /sbin/ping -c 3 129.67.1.165 + +where the address you give is the address shown as the P-t-P address +in the ifconfig output. If the link is operating correctly, you +should see output like this: + + 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 + --- 129.67.1.165 ping statistics --- + 3 packets transmitted, 3 packets received, 0% packet loss + round-trip min/avg/max = 247/260/268 ms + |