Irix PPP Installation and Configuration Guide

Prior to IRIX-6.3, there is little GUI (visual tool) support for configuring modems, and much less configuring PPP. Even so, the tool does not adequately handle all cases. Therefore, this document will only discuss configuration using a shell, and these instructions presume at least limited familiarity with text editors, such as vi or jot. You need to be familiar with the shell method to do debugging, even with the GUI tool.

Verifying Software Installation Status

Type the following to verify software installation:

   % versions  eoe{1,2}.\*.{uucp,ppp}

I = Installed, R = Removed

   Name                 Date      Description

I  eoe2                 03/24/95  IRIX Execution Environment 2, 5.3 with XFS
I  eoe2.man             03/24/95  IRIX Execution Environment Man Pages
I  eoe2.man.ppp         03/24/95  Point-to-Point Protocol Man Pages
I  eoe2.man.uucp        03/24/95  UNIX-to-UNIX Copy Man Pages
I  eoe2.sw              03/24/95  IRIX Execution Environment Software
I  eoe2.sw.ppp          03/24/95  Point-to-Point Protocol Software
I  eoe2.sw.uucp         03/24/95  UUCP Utilities

Modem Selection and Installation

IP Address Selection

You must have an IP address before you can finish your PPP configuration. The page on IP address selection can help you determine how to assign (or request) an IP address, and how to determine how to route packets (on a server).

Terminology

Setting the Dialout Configuration

• Local hostname and IP address
• Remote hostname and IP address
• Modem type
• Phone number
• Login
• Password
• IP address of a nameserver, the DNS host

/etc/hosts

Really only needs 3 or 4 entries, since all others can be obtained from the nameserver after a connection is made. The hosts file could look like (with appropriate substitutions):

127.0.0.1   localhost loghost
xx.yy.zz.ww myname.sub.domain myname
aa.bb.cc.dd remote.sub.domain remote
224.0.0.0   multicast

~uucp/Devices (/usr/lib/uucp in IRIX-4, /etc/uucp in IRIX-5)

Common for all versions to allow the use of cu for debugging connection problems. Make all additions and changes at the bottom of the file to simplify future updates. Use this example for port tty2:

Direct ttyd2 - Any direct
Direct ttym2 - Any direct
Direct ttyf2 - Any direct

In order to use cu for testing or configuring your modem, you must (as root) change the ownership of the ports to uucp:

chown uucp.uucp /dev/tty[dmf]2

Note that if you do this on a host on the LAN (or WAN), that anyone who can rlogin to your machine can use cu to call out on your modem. Since these additions are only used for debugging connections, you can delete them once your connection is working.

~uucp/Devices (/etc/uucp/Devices in IRIX-5.x)

The file entries are based upon the modem type. This example assumes a ZyXEL U-1496E modem running at 38400bps on port tty2. Add the following to the bottom of the file for each dialout modem. If all modems are "equivalent" (any modem to any destination), then use the same label for each modem (ACUslip), otherwise you'll need to make different labels for each class of modem. Make sure that the last field (zy1496 in this example) is in your dialers file, or PPP will fail "mysteriously"!

ACUslip ttyf2 null 38400 212 x zy1496

~uucp/Systems (/etc/uucp/Systems in IRIX-5)

This is the "smarts" for dialing the modem and logging into the server (to start PPP). This is a "standard" chat script, modifications may be made in some circumstances. Put all entries at the end of the Systems file. There may be more than one line with the same remote name if you are using either a different modem or a different phone number (or both). Each entry should be made on a single line (this one is split to make it fit in the window better -- make sure that there is a space between the two joined parts):

Premote Any ACUslip 38400 phone_number "" \r\c \
     ogin:--ogin: login_name assword: password framing

Irix PPP sends out a message with the framing name ("starting PPP") before actually starting the protocol; adding a final match of "PPP" ensures that the login really succeeded. Other server systems send out a similar string when starting PPP (but you need to check!). It is a good idea to have the chat script match that informational string to ensure that the login succeeded. I make the convention or prefixing remote with "P" for PPP, followed by the hostname.

#!/bin/sh
# ppp boot startup script
case $1 in
   start)
       /etc/killall ppp
       if /etc/chkconfig ppp && test -x /usr/etc/ppp -a -s /etc/ppp.conf
       then
           /usr/etc/ppp -r rmt &
       fi
       ;;
   stop)
       /etc/killall -TERM ppp
       ;;
   *)
       echo "usage: $0 {start|stop}"
       ;;
esac

rmt quiet remotehost=rmt localhost=client
       uucp_name=Prmt active_timeout=300 inactive_timeout=30
       add_route

For any dynamically dialed setup (IRIX-5 or 6 PPP with "quiet" option), you can start a link via a ping or rlogin or almost anything that wants to go over the link. The connection times out and hangs up the phone after a programmable idle time, then re-dials when the traffic resumes. This can save a lot of money if you are connecting long distance! The idle times are configurable (see the ppp man page). Note that it takes about 30 seconds for the first packet to get through when starting an idle line, so active timeouts much less than a couple of minutes are more frustrating than useful.

Most ISPs want to use server-assigned IP addresses. This saves IP address numbers, and reduces routing problems for them. While you can do this in quiet mode, it is neither recommended nor reliable. You need to run in out mode, and PPP must be manually started and stopped each time. A typical /etc/ppp.conf entry might look like:

rmt out remotehost=0,0 localhost=0,0
        uucp_name=Prmt add_route

If the other machine you are connecting to is not an SGI machine, you may have to add the -mp -ccp keywords to get PPP to connect (you may also need to add this if one of the hosts is running IRIX-6.2). Some PPP implementations do not handle the negotiation correctly, and this can cause the negotiation to fail, thus causing the connection to fail.

Accessing the Larger Network

• Some General IRIX configuration issues to make a PPP connected workstation perform better.
• Communicating to other hosts using their name instead of their IP address requires that name resolution be working. The correct configuration is different than when a host is on the LAN.

• Someday I'll finish writing up the list of hints on working remotely...

1. Setting up the modem (or modems). Basically the same as for dialout.
2. Setting up the security on the machine. Important!
3. Adding the support for PPP client(s) to dial in.

Security Issues

Enabling PPP Client Dialin

Debugging Your Installation