UNIX Serial Port Resources – SLIP, PPP, & PPPoE

This content was originally created, collected, and maintained by Stokely Consulting.
It has moved to SunHELP as of May 2005, and all further updates are done by Bill Bradford.


PPP & PPPoE

PPP FAQs & Info by Operating System:
Sun |SGI |Tadpole |Linux |Tru64 |SCO | AIX |BSD | PPP Books |PPP RFCs & General Information | PPP Tools | Public Domain/Free/Shareware PPP | Commercial PPP | PPPoE


PPP FAQs & Info – Sun:

There are lots of Sun PPP FAQs now, each with different strengths, each with a different writing style. Pick the one that sounds like it’s for your setup,
but don’t be afraid to try more than one. They’re all “correct”.

Before you set up PPP, you have to set up your modem and serial port. For Suns, learn how to set up the port and modem from
Celeste’s Tutorials on Solaris 2.x or SunOS 4.1.x Modems and Terminals.

General PPP-on-Solaris notes:

Does your Solaris PPP connection dial out too often? Try this tip from the Solaris 2 FAQ:

Q: My dial-on-demand link keeps dialing out, seems DNS related.
A: The nscd (name service cache daemon) tries to keep a hotlist of hosts; these hosts are refreshed regularly so they won't get removed from the cache. This feature should be disabled on systems with dial-on-demand links. Edit /etc/nscd.conf and change the hot-count line for hosts to:

keep-hot-count hosts 0

Thinkpad and COM1 configuration shows the steps needed to untangle the IBM Thinkpad’s IR interface from COM1, so that you can run a null modem interface from COM1 under Solaris. Written by David Henry.



Go to information specifically for: Solaris 9 PPP 4.0 | Solaris 7/8 Bundled PPP | Solaris 2.x Solstice 3.x PPP | Solaris 2.6 Bundled PPP | Solaris 2.0-2.5.1 Bundled PPP |Suns with unbundled, 3rd-party, or public domain PPPs


Solaris 9 PPP 4.0:

Sun Server (dial-in) and client (dial-out) PPP:

Solaris 9 PPP 4.0 is a version of ANU 2.4 PPP. (asppp is no longer provided in Solaris 9.) PPP 4.0 supports asynchronous and synchronous communications, is configured with either files or options to the pppd command (or both), supports PAP and CHAP (v1 and v2), PPPoE, PAM authentication, and IPv6. Sun provides a translation script to convert an existing asppp configuration to Solaris PPP 4.0.

Getting started with the latest PPP software from Sun Microsystems is a great cookbook for understanding and setting up PPP and PPPoE built into Solaris 8 update 6 and later. Covers client and server PPP and PPPoE, with examples. Well written by Martha Starkey.

docs.sun.com Solaris 9 PPP 4.0 Sun’s documentation.


Solaris 7/8 Bundled PPP:

Sun Server (dial-in) PPP:

Configuring PPP dial-in on Solaris 7 and 8 gives detailed step-by-step instructions to configure Solaris 7 and 8 as a high-speed PPP server. Covers Sparc and Intel (x86), instructions on configuring Solaris and Win95/98 clients to dial into a Solaris system. Written by Mike Mann, as part of his excellent Solaris Resources at Kempton.

A Solaris Null-Modem PPP HOWTO contains quick and easy instructions for setting up PPP without a modem, using PPPv4 and IP forwarding. Written by Charles Homan.

Sun Client (dial-out) PPP:

Configuring PPP on Solaris 7 and Solaris 8 to connect to an ISP covers how to set up the bundled Solaris asppp, with links to specific instructions on connecting to Demon Internet, Netcom UK, U-Net and FreeServe. Written by Mike Mann as part of his excellent Solaris Resources at Kempton.

configppp.sh is a shell script which configures built-in PPP for Solaris 2.5 and higher.
Also see the short PPP guide and PPP PAP dial-in under Solaris on the site. Part of the Solaris hints at bolthole.com, also known as the home of “Phil’s Software”.


Solaris 2.x Solstice 3.x PPP:

Sun Server (dial-in)/ Client (dial-out) PPP:

You can find Solstice PPP 3.0.1 on the “Easy Access Server 3.0″ CDROM. It has support for SecureKey-style challenge and response login procedures.
Be sure to uninstall asppp before you install Solstice PPP. They don’t coexist well. Remove asppp with:

pkgrm SUNWapppu;pkgrm SUNWapppr;pkgrm SUNWpppkx;pkgrm SUNWpppk

Solstice PPP 3.0.1 client free download for Sun Solaris 2.6 and 2.7, Sparc and Intel Edition.


Solaris 2.6 Bundled PPP:

Sun Server (dial-in) PPP: [no known writeups]

Sun Client (dial-out) PPP:

Connecting to any ISP with Solaris 7 and Solaris 8 (also works for Solaris 2.6)

Covers how to set up the bundled Solaris 7/8/2.6 asppp, with links to specific instructions on connecting to Demon Internet, Netcom UK, U-Net and
FreeServe. Written by Mike Mann as part of his excellent Solaris Resources at Kempton.

Dennis Friedel’s great Hints to get Solaris 2.4/2.5/2.6 x86 working with PPP. Also contains information on how to get POP mail working and how to connect via PPP to a Windows NT server.

configppp.sh is a shell script which configures built-in PPP for Solaris 2.5 and higher.
Also see the short PPP guide on the site. Part of the Solaris hints at bolthole.com, also known as the home of “Phil’s Software”.

Dial-out PPP Setup is a great PPP how-to for Solaris, Linux, Windows 95/98/NT. It’s a sample chapter from Using & Managing PPP by Andrew Sun. The book provides an in-depth coverage of PPP for administrators. The book covers PPP for Solaris, Linux, Windows 95/98/NT, authentication, virtual networks and tunnels (including PPTP), modems, DNS, ARP, and debugging. Published by O’Reilly and Associates, available for order online.


Solaris 2.0 – 2.5.1 Bundled PPP:

Sun Server (dial-in) PPP:

Dave Brillhart’s PPP cookbook describes how to get PPP running between a PC with Windows and a Sun running Solaris 2.x.

Sun Client (dial-out) PPP:

Overview of Configuring Solaris 2.5 PPP, includes dynamic IP address assignment, contributed by Bob Friesenhahn.

Setting up Sun ISDN with PPP dial-on-demand with Solaris 2.5.1 by Martin Hargreaves. (Hargreaves’ title for this document is "Connecting to Demon Internet using SUN’s ISDN"

Solaris x86 2.5 Dialup PPP Configs shows specific modifications made to PPP files to set up a dial-up PPP session from Solaris x86 2.5 with a USR Sportster 28.8 modem. Great explanation of file syntax, shows modem register settings. By Bruce Riddle.

Dennis Friedel’s great Hints to get Solaris 2.4/2.5/2.6 x86 working with PPP. Also contains information on how to get POP mail working and how to connect via PPP to a Windows NT server.

configppp.sh is a shell script which configures built-in PPP for Solaris 2.5 and higher.
Also see the short PPP guide on the site. Part of the Solaris hints at bolthole.com, also known as the home of “Phil’s Software”.

How to setup Solaris 2.x dial-out PPP or Yet another Solaris 2.x PPP guide
includes step-by-step instructions for setting up dial-out PPP. Wonderfully irreverent. Good routing info. Written by Andy Polyakov.

Setting Up Solaris as PPP Client for Solaris 2.4 and 2.5, includes Zoom V.32bis modem strings and useful scripts to control PPP with locking for connecting to more than one PPP server using the same modem. Written by Khalid Aziz and Shuah Khan.

SunService PPP Tip Sheet: SunService Tip Sheets are available to Sun contract customers at http://sunsolve.sun.com.


Suns with unbundled, 3rd-party, or public domain PPPs:

Sun Server (dial-in) PPP: No how-tos found.

Sun Client (dial-out) PPP:

Connecting a Private Network to an ISP on Solaris uses IP-Filter to do NAT (network address translation) and DP package. Good, very-detailed information. Written by Doug Palmer.

Dial Up Modem Setup with PPPD for Solaris 2.6 x86 on com2. Shows the changes to all the necessary files. Written by Dave England.

PPP + Slirp contains a recipe to build and run PPP-2.2 on SunOS 4.1.1 to communicate with a remote host running Slirp. Also includes slirp help files, and scripts to bring ppp-2.2 up and down. Written by Eric De Mund.

Setting Up Solaris on Intel Platforms covers setting up internal, external, and PCMCIA modems as well as pppd for Solaris x86 2.6 and 2.7. Links to pre-compiled pppd. Well-written by Gregory A. Lazzaro.

See also our PPP Tools section for the X-ISP tool for Linux pppd, and our Public Domain, Free & Shareware PPP section for links to the public-domain PPP software packages.

PPP FAQs & Info – Tru64:

PPP on Tru64 5.1 is a mini howto on configuring a Tru64 machine with external modem to Earthlink.


PPP FAQs & Info – Linux:

Callback PPP: One Way It Works shows you how to set up callback PPP on Red Hat Linux 5.0 server, with Solaris, Linux or Win95 clients. Uses mgetty, ppp-2.3.3, icmake, and callback. Written by Brent Martin.

Red Hat Product Support has several PPP tips to use when all else fails.

Dial-out PPP Setup is a great PPP how-to for Solaris, Linux, Windows 95/98/NT. It’s a sample chapter from Using & Managing PPP by Andrew Sun. The book provides an in-depth coverage of PPP for administrators. The book covers PPP for Solaris, Linux, Windows 95/98/NT, authentication, virtual networks and tunnels (including PPTP), modems, DNS, ARP, and debugging. Published by O’Reilly and Associates, available for order online.

How to hook up PPP in Linux is a straightforward and detailed how-to for 2.0 – 2.2.x Linux kernels. Good PAP/CHAP coverage. Written by Bill Unruh. Bill has another fine article, Initial PPP Setup, for Linux 2.0-2.2.x kernels and pppd 2.3.3 and greater.

Linux Dialin Server Setup is a step-by-step guide to setting up a PPP and SLIP Linux server. Written by Josh Gentry.

Linux PPP Howto describes how to connect a Linux PC to a PPP server, how to use PPP to link two LANS together, and provides one method of setting up your Linux computer as a PPP Server.

MetaLab/ibiblio’s Linux Archivecontains documents on setting up SLIP, PPP, NFS, IPX, NIS, Token Ring, Appletalk, ISDN, firewalling, IP tunnelling and more.


PPP FAQs & Info – SCO:

Configuring Facet TA PPP on SCO Unix OpenServer 5.0.X covers the setup of dynamic incoming connections.

Quick PPP Setup describes how to get PPP into the SCO kernel then set it up to connect to your ISP. Written by Anthony Lawrence.


PPP FAQs & Info – Tadpole Sparcbook:

Tadpole – search the site for the SPARCBOOK PPP Installation and Setup, Tadpole SPARCBOOK Modem Setup to learn to configure auto-answer and dialout.


PPP FAQs & Info – Silicon Graphics:

Guide to setting up PPP under Irix 6.2 uses a Hayes Smartmodem Optima 28800 V.34/V.FC + FAX on an SGI Indy.

Silicon Graphics – search for Connecting to an ISP using PPP under Irix 5.3.

SGI Indy on the Internet for Irix 6.5.6 and 6.2. Detailed instructions include making your own modem cable.


PPP FAQs & Info – AIX:

Basic PPP Setup Guide for AIX 4.1.4, 4.1.5, and 4.2 covers setting up AIX as a PPP Client and Server, PAP and CHAP authentication.


PPP FAQs & Info – BSD:

Adventures in dial-up covers basic dial-up server setup in BSD systems.

Dial Out Connection in FreeBSD explains how to configure a PPP connection in FreeBSD.

Point to Point Protocol contains set up information for FreeBSD user-level PPP. Sources, man pages, links and examples.

ppp-setup is a script to automatically setup user PPP in FreeBSD.


PPP Books:

PPP Design and Debugging, written by James D. Carlson, is useful in understanding and debugging PPP. Published by
Addison Wesley Longman Computer & Engineering Publishing Group.

Using & Managing PPP by Andrew Sun, provides an in-depth coverage of PPP for administrators. The book covers PPP for Solaris, Linux, Windows 95/98/NT, authentication, virtual networks and tunnels (including PPTP), modems, DNS,
ARP, and debugging. The sample chapter Dial-out PPP Setup is a great PPP how-to, available online. Published by O’Reilly and Associates, available for order online.


PPP RFCs & General Information:

groups.google.com search of comp.protocols.ppp: Search or browse the comp.protocols.ppp newsgroup at groups.google.com.

PPP Documentation is an excellent short description of PPP’s background, components, operation, physical layer requirements, link layer and link-control protocol. From Cisco.


PPP RFCs:

RFC1661: PPP core protocol
RFC2153: PPP Vendor Extensions
RFC1331: The PPP for the Transmission of Multi-protocol Datagrams over PPP Links RFC
RFC2023: IP Version 6 over PPP
RFC1994: PPP Challenge Handshake Authentication Protocol (CHAP)

There are about 79 RFCs which address some aspect of PPP. Get the index of all RFCs from the Internet Engineering Task Force (IETF) and search the page for PPP. You can also use the RFC Editor‘s
search page.

Comp.protocols.ppp FAQ contains excellent information.


PPP Tools:

configppp.sh is a shell script which configures built-in PPP for Solaris 2.5 and higher. Also see the short PPP guide on the site. Part of the Solaris hints at bolthole.com, also known as the home of “Phil’s Software”.

EzPPP for Linux is a graphical interface for pppd-2.x and frees you from having to deal with chat scripts. Uses and includes the Qt library.

PPP Configurator for Linux PPP connections asks you questions and generates your connection scripts for you.

SerialView is a commercial DOS based async protocol analyzer that supports capture and decode of async SLIP, PPP and NRN (Novell Remote Node) protocols. SerialView decodes LCP, PAP, CHAP, IPCP, IPXCP, ATCP and NBFCP, TCP/UDP/IP, SNMP, IPX/SPX/NCP and more. From Klos Technologies, Inc.

X-ISP is a free, visual, X11/XForms-based, user-friendly interface to pppd/chat for Linux. It may compile on other Unix versions.


Public Domain, Free & Shareware PPP:

iij-ppp for HP/UX: It seems that HP does not support PPP on their workstations, only SLIP. But, iij-ppp has been ported to HP/UX 9.x and 10.x. This site has the source, example configurations, and documentation for iij-ppp.

Solstice PPP 3.0.1 client free download for Sun Solaris 2.6 and 2.7, Sparc and Intel Edition.

ppp(d) 2.x:

ppp-2.3.11 through ppp-2.4.1 sources from Paul Mackerras. This free software source code is implemented using STREAMS modules on Solaris 2.x, SunOS 4.x, AIX 4.1 and OSF/1, and as a line discipline under Ultrix, NeXT, NetBSD, FreeBSD, and linux. It accepts dynamic IP address allocation from your ISP, but has only limited support for your machine assigning dynamic IP addresses to machines dialing in. Many different OSs supported. Supports packet compression.

pppd-2.2/2.3.*/2.4.* sources for Linux, Solaris, SunOS 4. From linuxcare.com.au.

pppd-2.3.5 and Solaris 7:

ppp-2.3.5 compiles on Solaris 2.6 x86, but has problems compiling on Solaris 7. To fix this, change table name u to something else like u1, on every line in which table name "u" is used in common/zlib.c

Example: change
inflate_huft *u[BMAX]
to
inflate_huft *u1[BMAX]

pppd 2.3.1 for Solaris x86 2.5.1 is a drop-in replacement for Solaris x86 2.5.1 asppp. Site contains pre-compiled source for Solaris x86 and instruction. From Peter Marelas of Phase One Interactive.

See also the PPP Tools section for several tools for pppd.

See also the Suns with unbundled, 3rd-party, or public domain PPPs section for how-tos about pppd on Suns.


Commercial PPP:

Solstice PPP 3.0.1 Server for Solaris 2.4 and up, Sparc and X86, available from Sun.

Solstice PPP 3.0.1 client free download for Sun Solaris 2.6 and 2.7, Sparc and Intel Edition.


PPPoE – PPP over Ethernet:

Point to Point Protocol over Ethernet (PPPoE – RFC2516) is a proposal specifying how a host personal computer interacts with a broadband modem (i.e. xDSL, cable, wireless, etc.) to achieve access to high-speed data networks. PPPoE is not a serial PPP connection, but we get a lot of mail from readers looking for information about PPPoE. The easiest way to connect a Unix machine via PPPoE is via a router that handles PPPoE for you, like a Netgear or a Linksys router. But, many of us Unix propeller-heads like to do it ourselves.

Getting started with the latest PPP software from Sun Microsystems is a great cookbook for understanding and setting up PPP and PPPoE built into Solaris 8 update 6 and later. Covers client and server PPP and PPPoE, with examples. Well written by ML Starkey.

A Step-by-Step Guide to Building an OpenBSD PPPoE Gateway, with Firewall for OpenBSD 2.9. Clearly written.

gpppoe-conf, the PPPoE Configurator, is a free Gtk2 tool for easily creating ppp accounts.
It also includes a tool for configurating Speedtouch modems.

How to configure the PPPoE on Solaris 8 10/01 (Maintenance Update 6): PPPoE is built in to Solaris 8 10/01 (update 6) and later as part of the PPPD 4.0 packages. This free InfoDoc 43092 from sunsolve.sun.com describes how to set up PPPoE on Solaris.

PPPoE FAQs links to PPoE FAQs for Linux, Windows, Mac, general xDSL FAQs and more. Provided by Carrick Solutions Ltd.

RFC2516, Method for Transmitting PPP Over Ethernet (PPPoE).

Roaring Penguin’s PPPoE Client is free software for Linux (2.0- or 2.2-series kernel)
using an ADSL modem. User-mode program which does not require kernel modifications.

Roaring Penguin RP-PPPoE Forum is a place for users to discuss issues with rp-pppoe.

Solaris x86: Connecting to Sympatico High Speed Edition Service describes how to use Solaris
x86 with ADSL, Bell’s Sympatico HSE service, pppd-2.3.11 and PPPoE via rp-pppoe.


SLIP and other Serial IP Protocols

C-SLIP 2.7, available via anonymous ftp (202KB).

PPP + Slirp contains a recipe to build and run PPP-2.2 on SunOS 4.1.1 to communicate with a remote host running Slirp. Also includes slirp help files, and scripts to bring ppp-2.2 up and down. Written by Eric De Mund.

Also see the PPP section above for some of the PPP products which also speak SLIP.