Instructions for Linux Users

Instructions for Linux Users (Intel Computers Only)

Requirements
- Kernel: You should be using Linux kernel 1.2.13 or higher. If not, you might want to upgrade (see http://www.redhat.com for details).
- PPP: You need to have the PPP package (which includes pppd and chat) and PPP support compiled into the kernel.
  - Do I have PPP?: If your Linux distribution does not include the PPP software, you will need to obtain this from ftp://sunsite.unc.edu/pub/Linux/system/network/serial/ppp/ppp-2.3.4.tar.gz. The PPP package contains instructions on how to compile and install the software.
  - Do I have PPP running?: To know whether you already have PPP support in the kernel run dmesg or, as superuser, look at /var/log/messages and check for lines such as the following:
```
    PPP: version 2.2.0 (dynamic channel allocation)
    TCP compression code copyright 1989 Regents of the University of California
    PPP Dynamic channel allocation code copyright 1995 Caldera, Inc.
    PPP line discipline registered.
```
    If no such lines are found then you need to make and install a new kernel with PPP and networking support. In this case consult the Kernel-HOWTO at The Linux Kernel HOWTO http://sunsite.unc.edu/mdw/HOWTO/Kernel-HOWTO.html.
Checking System Network Configuration Files
Configuration files may be changed by direct editing or by special distribution-dependent configuration tools such as linuxconf in the RedHat distribution. In this section we show what the files should look like. For information on how to use RedHat's configuration tools, see below.
- Nameserver file: Check the file /etc/resolv.conf. It should look like this:
```
    search localhost 
    nameserver 129.137.178.240
    nameserver 129.137.8.114
```
  If it doesn't, edit the file as superuser or, if you are using RedHat, run the control-panel or linuxconf as superuser and edit the network description (see below).
- Hosts file: You might want to have the file /etc/hosts look something like this:
```
    127.0.0.1  localhost  loopback
    129.137.10.199  franco.ececs.uc.edu  franco
```
  Although the second line is not necessary for a successful ppp installation, you might want to include one like it for other reasons (it seems to me that linux does not enjoy the feeling of not being networked). Of course, if you add such a line, do not use my hostname, use your own. If you do not know what your hostname is and you are networking only through ppp, then make one up. However, in that case you should observe standard rules for choosing such names.
- Networks file: There should be a file /etc/networks that looks like this:
```
    loopback   127.0.0.0   localhost
```
- Other files: There are some other distribution-dependent files that should be checked. In RedHat 5.1, there should be a file /etc/sysconfig/network which contains lines such as these:
```
    NETWORKING=yes
    HOSTNAME=franco.ececs.uc.edu
    DOMAINNAME=ececs.uc.edu
    GATEWAY="129.137.8.249"
    GATEWAYDEV=""
    FORWARD_IPV4=no
    ...
```
  where franco.ececs.uc.edu and ececs.uc.edu are my hostname and domain and you should substitute your own. If you have already had a UC PPP account in the past, editing this file is probably unnecessary. If you are uncomfortable editing this file, you may run control-panel or linuxconf as superuser (see below). For other distributions, make sure the gateway is set in the appropriate file.
  Also in RedHat 5.1 there is a file /etc/sysconfig/network-scripts/ifcfg-ppp0 which should have some lines looking like this:
```
    DEVICE="ppp0"
    IPADDR=""
    NETWORK="129.137.8.0"
    NETMASK="255.255.252.0"
    ONBOOT="no"
    BOOTPROTO="none"
    PPPOPTIONS=""
    MODEMPORT="/dev/cua1"
    LINESPEED="115200"
    ESCAPECHARS="no"
    DEFABORT="no"
    HARDFLOWCTL="yes"
    PAPNAME="franco"
    REMIP=""
    MTU=""
    MRU=""
    ...
```
  Important: Modem port /dev/cua1 corresponds to COM2. If your modem is on another port you should change the line above accordingly. The easiest way to do this is by means of the in the control-panel or by using linuxconf (see below). Usually, /dev/modem will work.
  If you are uncomfortable editing this file, you may use control-panel or linuxconf as superuser. For other distributions, make sure the network and netmask numbers for the ppp0 device are set in the appropriate file. If you have already had a UC PPP account in the past, this step is probably unnecessary.
Checking PPPD Permissions
The pppd software must be run setuid. Check with the following:
```
    ls -l /usr/sbin/pppd
```
You should see something like this:
```
    -rwsr-xr-x   1 root     root       104876 Apr 24 06:14 /usr/sbin/pppd* 
```
If the s is missing from -rwsr-xr-x, as superuser execute:
```
    chmod u+s /usr/sbin/pppd
```
Editing the PPP Options and PAP-Secrets Files
- Options: The file /etc/ppp/options should be edited as superuser so the following options are uncommented and all others are commented:
```
    asyncmap 0
    crtscts
    defaultroute
    lock
    modem
    netmask 255.255.252.0
    noipdefault
    -detach
    name your-username
    user your-username
```
  where your-username is the account name supplied by CITS.
- Pap-secrets: The file /etc/ppp/pap-secrets should be edited as superuser to look like this:
```
    # PAP secrets file
    # remotenames ppp-n are reserved for netcfg
    # Format:
    # name  remote  secret
    your-username   *   your-password
```
  where your-username is the account name supplied by CITS and your-password is the password you have chosen for the account when you filled in the application for an account. The star (*) is important, so do not leave it out. Separate the three entries on the last line with blanks.
- Permissions: should be the following:
```
    -rwx------   1 root     root         9562 Jul 10 21:52 options* 
    -rwx------   1 root     root          141 Jul  9 02:52 pap-secrets*  
```
Creating and Installing Scripts
You need to supply two scripts, one to connect to UC and one to drop the connection. Both will reside in /usr/local/bin. Because the new PPP connection software used by CITS requires PAP (Password Authentication Protocol) and the old one didn't and because users are limited to one login at a time, there are some subtle changes to previous scripts that must be made or you will tear your hair out for days trying to figure out why the connection drops 10 seconds after it is established.
- Connect Script: Create a file, as superuser, called ppp-uc in directory /usr/local/bin with the following contents:
```
    #!/bin/sh
    kill -9 `ps aex | grep chat | awk '{print $1}'`
    kill -9 `ps aex | grep pppd | awk '{print $1}'`
    setserial /dev/cua1 spd_vhi
    /usr/sbin/pppd connect 'chat -e ABORT BUSY ABORT "NO CARRIER" "" "\dat\&fL3dt8619503" CONNECT' /dev/cua1 115200
```
  In this case we have assumed your modem is Hayes compatible and is connected to /dev/cua1 (COM2).
  Please carefully notice that the chat script (between ' characters) only dials the number and waits for a response from CITS. It does not login as with previous scripts. This is important. Also, please change /dev/cua1 to whatever port your modem is connected to. Usually, /dev/modem can be used without problems.
- Disconnect Script: Create a file, as superuser, called ppp-off in directory /usr/local/bin with the following contents:
```
    #!/bin/sh
    kill -9 `ps aex | grep chat | awk '{print $1}'`
    kill -9 `ps aex | grep pppd | awk '{print $1}'`
```
  This file merely finds the handles for the chat and pppd processes and kills them.
- Permissions: should be set as follows:
```
    -rwxr-xr-x   1 root     root          370 Jul 11 08:11 /usr/local/bin/ppp-uc* 
    -rwxr-xr-x   1 root     root          159 Jul  5 11:25 /usr/local/bin/ppp-off* 
```
Running the Scripts - Making a Connection and Quitting
- Connecting: To connect to UCRA II while not in X windows execute:
```
    ppp-uc >& /dev/null &
```
  To connect from X windows you can do a number of creative things in addition to directly executing ppp-uc as above. If you are running fvwm, for example, you can add a line to your menus that brings up the connection with a click. For example,
```
    Exec "PPP to UC" exec rxvt -T PPP +sb -font 6x12 -bg LightSkyBlue -geometry +100+100 -e /usr/local/bin/ppp-uc
```
  Then you can customize the connect script to let you know exactly when you can start issuing remote commands.
- Disconnecting: To disconnect while not in X windows execute:
```
    ppp-off
```

Testing That You Have a Connection
There are two standard ways to do this: execute

    ifconfig

in which case there should be a section of the output that looks like this:

    ppp0      Link encap:Point-to-Point Protocol
              inet addr:129.137.229.78  P-t-P:129.137.231.248  Mask:255.255.252.0
              UP POINTOPOINT RUNNING  MTU:1500  Metric:1
              RX packets:15 errors:0 dropped:0 overruns:0
              TX packets:16 errors:0 dropped:0 overruns:0

and execute

    route -n

which produces output such as the following:

    Kernel IP routing table
    Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
    129.137.231.248 0.0.0.0         255.255.255.255 UH    0      0        0 ppp0
    127.0.0.0       0.0.0.0         255.0.0.0       U     0      0        2 lo
    0.0.0.0         129.137.231.248 0.0.0.0         UG    0      0        0 ppp0

If you see the line beginning 127.0.0.0 but not the lines containing 129.137.231.248 there is a problem. Never attempt to correct this by using the route command to add inet routes and gateways yourself. This will lead to more frustration.

Debugging

Normal response: If the connection is made correctly, something like the following will appear near the end of the file /var/log/messages:

    Jul 11 11:34:17 franco pppd[9198]: pppd 2.3.3 started by franco, uid 500
    Jul 11 11:34:40 franco pppd[9198]: Serial connection established.
    Jul 11 11:34:41 franco pppd[9198]: Using interface ppp0
    Jul 11 11:34:41 franco pppd[9198]: Connect: ppp0 <--> /dev/cua1
    Jul 11 11:34:44 franco pppd[9198]: Remote message:
    Jul 11 11:34:47 franco pppd[9198]: local  IP address 129.137.229.78
    Jul 11 11:34:47 franco pppd[9198]: remote IP address 129.137.231.248

Problems: If the connection can not be made, add the options debug and kdebug15 to the /etc/ppp/options file (as superuser). Compare your message log to the following which is the log showing a normal connection. This should help you determine where the problem is.

    Jul 11 14:12:53 franco pppd[11172]: pppd 2.3.3 started by franco, uid 500
    Jul 11 14:12:53 franco pppd[11172]: Removed stale lock on cua1 (pid 9198)
    Jul 11 14:13:17 franco pppd[11172]: Serial connection established.
    Jul 11 14:13:18 franco kernel: ppp_tty_ioctl: set flags to f0000
    Jul 11 14:13:18 franco kernel: ppp_tty_ioctl: set flags to f0000
    Jul 11 14:13:18 franco kernel: ppp_tty_ioctl: set xasyncmap
    Jul 11 14:13:18 franco kernel: ppp_tty_ioctl: set xmit asyncmap ffffffff
    Jul 11 14:13:18 franco kernel: ppp_tty_ioctl: set flags to f0000
    Jul 11 14:13:18 franco kernel: ppp_tty_ioctl: set mru to 5dc
    Jul 11 14:13:18 franco kernel: ppp_tty_ioctl: set rcv asyncmap ffffffff
    Jul 11 14:13:18 franco kernel: ppp_tty_ioctl: set flags to f0000
    Jul 11 14:13:18 franco pppd[11172]: Using interface ppp0
    Jul 11 14:13:18 franco pppd[11172]: Connect: ppp0 <--> /dev/cua1
    Jul 11 14:13:18 franco kernel: ppp_dev_stats called<7>ppp: receive buffer, count = 8
    Jul 11 14:13:18 franco kernel: ppp: successfully queued 41 bytes, flags = f0f0000
    Jul 11 14:13:18 franco kernel: ppp_dev_stats called<7>ppp: receive buffer, count = 16
    Jul 11 14:13:18 franco kernel: ppp: successfully queued 26 bytes, flags = f0f0000
    Jul 11 14:13:21 franco kernel: ppp_dev_stats called<6>ppp_dev_stats called<6>ppp: write frame, count = 24
    Jul 11 14:13:21 franco kernel: ppp_dev_stats called<7>ppp: receive buffer, count = 8
    Jul 11 14:13:21 franco kernel: ppp: successfully queued 22 bytes, flags = f0f0000
    Jul 11 14:13:21 franco kernel: ppp_tty_ioctl: set xmit asyncmap 0
    Jul 11 14:13:21 franco kernel: ppp_tty_ioctl: set flags to f0f0003
    Jul 11 14:13:21 franco kernel: ppp_tty_ioctl: set mru to 5dc
    Jul 11 14:13:21 franco kernel: ppp_tty_ioctl: set rcv asyncmap 0
    Jul 11 14:13:21 franco kernel: ppp_tty_ioctl: set flags to f0f0003
    Jul 11 14:13:21 franco kernel: ppp_dev_stats called<6>ppp_dev_stats called<7>ppp: receive buffer, count = 11  
    Jul 11 14:13:21 franco kernel: ppp: successfully queued 7 bytes, flags = f0f0003
    Jul 11 14:13:21 franco pppd[11172]: Remote message:
    Jul 11 14:13:21 franco kernel: ppp_tty_ioctl: set flags to f0f0043
    Jul 11 14:13:21 franco kernel: ppp_dev_stats called<7>ppp: receive buffer, count = 36   
    Jul 11 14:13:21 franco kernel: ppp: successfully queued 16 bytes, flags = f0f0043
    Jul 11 14:13:21 franco kernel: ppp: successfully queued 12 bytes, flags = f0f0043
    Jul 11 14:13:23 franco kernel: ppp_dev_stats called<6>ppp_dev_stats called<6>ppp_dev_stats called<7>ppp: receive buffer, count = 48  
    Jul 11 14:13:23 franco pppd[11172]: Unsupported protocol (0x8029) received
    Jul 11 14:13:23 franco pppd[11172]: Unsupported protocol (0x802b) received
    Jul 11 14:13:23 franco kernel: ppp: successfully queued 55 bytes, flags = f0f0043
    Jul 11 14:13:23 franco kernel: ppp: successfully queued 34 bytes, flags = f0f0043
    Jul 11 14:13:23 franco kernel: ppp: successfully queued 12 bytes, flags = f0f0043
    Jul 11 14:13:23 franco kernel: ppp: successfully queued 6 bytes, flags = f0f0043
    Jul 11 14:13:23 franco kernel: ppp: successfully queued 11 bytes, flags = f0f0043
    Jul 11 14:13:23 franco kernel: ppp_dev_stats called<7>ppp: receive buffer, count = 28
    Jul 11 14:13:23 franco kernel: ppp: successfully queued 12 bytes, flags = f0f0043
    Jul 11 14:13:23 franco kernel: ppp: successfully queued 8 bytes, flags = f0f0043
    Jul 11 14:13:24 franco kernel: ppp_dev_stats called<7>ppp: receive buffer, count = 16
    Jul 11 14:13:24 franco kernel: ppp: successfully queued 12 bytes, flags = f0f0043
    Jul 11 14:13:24 franco kernel: ppp_tty_ioctl: set flags to f0f004b
    Jul 11 14:13:24 franco kernel: ppp: channel ppp0 going up for IP packets!
    Jul 11 14:13:24 franco pppd[11172]: local  IP address 129.137.229.177
    Jul 11 14:13:24 franco pppd[11172]: remote IP address 129.137.231.251
    Jul 11 14:13:24 franco kernel: ppp: successfully queued 6 bytes, flags = f0f004b
    Jul 11 14:13:24 franco kernel: ppp_tty_ioctl: set flags to f0f00cb
    Jul 11 14:13:25 franco kernel: ppp_dev_stats called<6>ppp_dev_stats called<6>ppp_dev_stats called<6>ppp_dev_stats called<7>ppp_tty_read: called buf=08063e50 nr=1504

Do not forget to change the /etc/ppp/options to remove the debugging feature after you have reliable connection scripts and configuration files or else you will accumulate a lot of junk you don't want.

Using the RedHat Linuxconf Tool for Network Configuring
To run linuxconf you must have a RedHat installation and superuser access. Login as superuser and run linuxconf. The page LinuxConf may be accessed to see screen dumps showing what you should enter in the various linuxconf dialog boxes.
Using the RedHat Control-Panel for Network Configuring
To run the control-panel you must have a RedHat installation and superuser access. Login as superuser and run control-panel. The page Control-Panel may be accessed to see screen dumps showing what you should enter in the various control-panel dialog boxes. The pictures do not show how to enter PAP information. So, if the control panel is used, the PAP-secrets file must be adjusted manually.