Questions and Answers

The kppp Handbook
Prev |  | Next

# Chapter 10. Questions and Answers

1. Questions about Dialling
  10.1.1. I can't get kppp to work. kppp tells me pppd has died or that a timeout has expired. What's going on?
  10.1.2. Why does kppp tell me Sorry, can't open the modem?
  10.1.3. Why does kppp tell me it can't create a modem lock file?
  10.1.4. Why is kppp installed with the SETUID bit on?
  10.1.5. What do I do when kppp just sits there and waits with the message: `Expecting OK`
  10.1.6. The connection works fine, but I can't start any applications!
  10.1.7. kppp reports a successful connection, but Konqueror just says Unknown host `hostname`, and Netscape® reports The server does not have a DNS entry.
  10.1.8. How do I make kppp send a \n or a \r
  10.1.9. How can I stop kppp complaining: Can't create lock file?
  10.1.10. Why is my modem making so much noise when dialling?
  10.1.11. I turned the modem volume to "Off" and verified the modem commands, but I still hear that awful noise during dialling. Why?
  10.1.12. kppp keeps reporting unusual modem speeds like "115200" or "57600"
  10.1.13. Why does kppp report "Unknown speed"
  10.1.14. I get a slow connection speed
  10.1.15. I get a REALLY slow connection speed!
  10.1.16. My phone line needs pulse dialling instead of tone dialling (or vice-versa). How do I change that?
2. Questions about Telephone Cost Rules
  10.2.1. How do I write a telephones cost rules file?
  10.2.2. I have written a telephone cost rules for my region. Where can I submit it so that others can make use of it?
  10.2.3. Can my phone cost rulefile contain fractional time units like "(0.17, 45.5)"?
  10.2.4. My country observes other "moving" holidays than Easter.
3. Questions about the System Logs
  10.3.1. I see a message saying Serial line is looped back. What does this mean?
  10.3.2. The logs show Signal 15
  10.3.3. What about Receive serial link is not 8-bit clean
  10.3.4. and can't locate module ppp-compress? What's this?

### 1. Questions about Dialling

10.1.1. I can't get kppp to work. kppp tells me pppd has died or that a timeout has expired. What's going on?

Did you read this manual carefully? Here are once more the most common pitfalls:

- Click on the Details button. kppp will you give an excerpt from the PPP log messages (may not work on non-Linux® systems, or even on some Linux® distributions). The log will help you to track down the bug.

- Make sure that pppd is the actual pppd binary not a script

- Make sure that pppd is setuid root. You may set this mode by issuing `chmod `u+s pppd`` as root.

- Make sure that your `/etc/ppp/options` file exists and that it doesn´t contain any conflicting entries. If in doubt: Leave this file empty.

- Make sure that you don't use the option `lock` as an argument for pppd (kppp is already taking care of device locking).

- Remove the `lock` option from both your `/etc/ppp/options` and `˜/.ppprc` files!

- Using the symbolic link `/dev/modem` may cause some conflicts. Eliminate this source of trouble by using the real device, i.e. `/dev/cuaX` or `/dev/ttySX`.

  | COM1 equals `ttyS0`, COM2 is `ttyS1` and so on.

- Make sure you set the right permission. In case of trouble you might want to run it as root first and then later, when everything is working fine give it less harmful permission if you can not afford to run kppp setuid root. The proper way to proceed would probably be creating a modem group.

- You might be launching pppd too early, i.e. before the remote server is ready to negotiate a PPP connection. If you are using a login script, you should use the built-in terminal to verify your login procedure. Some providers will require you to issue a simple Send or Send ppp to launch PPP. Some users even reported, that they had to append Pause 1 or Pause 2 to their script to solve timing conflicts.

If nothing helps, you might obtain some debugging info from your systems log by issuing:

     # tail /var/log/messages

10.1.2. Why does kppp tell me Sorry, can't open the modem?

This means that kppp doesn't have permissions to open the modem device or that you selected a modem device on the Modem Tab Dialog that is not valid. First make sure you selected the right modem device. Once you are sure you have selected the right modem device, you must give kppp the right permission to access the modem device and to be able to modify `/etc/resolv.conf` in case you want kppp to configure DNS correctly for you. If you can afford to run kppp setuid root this would solve all access problems for you, if not you will have to figure out what the right permissions are for your purposes. In order to give kppp setuid root permissions do the following:

     % su root
     # chown root:root $KDEDIR/bin/kppp
     # chmod +s $KDEDIR/bin/kppp
     # exit

10.1.3. Why does kppp tell me it can't create a modem lock file?

This in most instances means that you have installed kppp without SETUID bit on while you, the person executing kppp, doesn't have write access to the lock file directory which by default is `/var/lock`. This for example is the case on Red Hat® systems. Check the modem dialog for the precise location you have chosen. The solution is easy -- either run kppp SETUID if you can afford to, or give regular users write access to `/var/lock` or create a modem group that will have access to the `/var/lock` file.

10.1.4. Why is kppp installed with the SETUID bit on?

para>There is no need for the SETUID bit, if you know a bit of UNIX® systems administration. Simply create a modem group, add all users that you want to give access to the modem to that group and make the modem device read/writable for that group. Also if you want DNS configuration to work with kppp, then `/etc/resolv.conf` must be read/writable by the members of that group. The same counts for `/etc/ppp/pap-secrets` and `/etc/ppp/chap-secrets` if you want to use the built-in PAP or CHAP support, respectively.

The kppp team has lately done a lot of work to make kppp setuid-safe. But it's up to you to decide if you install and how you install it.

You might also want to read the Security section.

10.1.5. What do I do when kppp just sits there and waits with the message: `Expecting OK`

Have you played with the CR/LF setting? Try CR, LF or CR/LF.

Alternatively, your modem might need some time to respond to its intialization. Open the Modem Commands dialog on the Modem tab and adjust the Pre-Init and Post-Init delays. See if you are successful when drastically increasing their values, and then do some fine-tuning later.

10.1.6. The connection works fine, but I can't start any applications!

You have probably selected the Auto Configure Host Name option, and the X Server has problems connecting to your newly named host. If you really need this option (and chances are you really don't), you are unfortunately on your own to set up the appropriate authorisations. Issuing `xhost `+`` before starting the connection would do the job, but be warned of the security risks involved, since this effectively gives everyone else access to your X Server.

10.1.7. kppp reports a successful connection, but Konqueror just says Unknown host `hostname`, and Netscape® reports The server does not have a DNS entry.

Try pinging another server by its IP number, e.g. `ping `195.0.254.76``. If that works, you could try the following:

- Check if you have provided kppp with at least one DNS address.

- Check the contents of `/etc/host.conf`. There should be a line saying something similar to `order hosts, bind`. The `bind` keyword advises the resolver library to include a name server query when performing an address lookup. If such a line is not there, try adding it.

10.1.8. How do I make kppp send a \n or a \r

Just send an empty string such as in the following script:

     Send                            # send an empty string
     Expect           ID:
     Send             itsme
     Expect           word:
     Send             forgot
     Expect           granted
     Send             ppp

10.1.9. How can I stop kppp complaining: Can't create lock file?

This happens because you don't have permissions to create a lock file. If you chose to use a lock file, you must have write permision to the directory (typically `/var/lock`). This is of course no problem if you have given kppp setuid permissions. Please read the section on Lock files.

10.1.10. Why is my modem making so much noise when dialling?

Click on Setup, then Modem. You can control the modem volume here in three steps: Off, medium and high. For most modems, medium or high result in the same volume. If changing this setting doesn't work, make sure the correct settings for your modem are specified in Setup, Modem, Modem Commands.

10.1.11. I turned the modem volume to "Off" and verified the modem commands, but I still hear that awful noise during dialling. Why?

The volume initialisation string can get lost if your modem can't cope with the speed it is receiving commands from kppp. Increase the value of Post-Init Delay in Setup, Modem, Modem Commands.

10.1.12. kppp keeps reporting unusual modem speeds like "115200" or "57600"

Many modems only report the speed of the serial line and not the speed over the telephone line as default. You must configure these modems to report the true line speed by adding some commands to the modem init or dial strings. For many modems this command is ATW2. If you want to add it to the dial string (which normally starts with ATD), the new dial string would be ATW2D.

10.1.13. Why does kppp report "Unknown speed"

New modems often have very complex connection messages like `CONNECT LAP.M/V42.bis/115000:RX/31200:TX`, and kppp cannot parse this message correctly. Turn on Show Log and you'll see the connection speed.

10.1.14. I get a slow connection speed

If you are not satisfied with the modem speed, make sure you've set the connection speed (you can reach it by clicking on Setup, Device, Connection Speed) to 57600 or higher. Make sure your serial ports support higher speeds. Many older systems based on i486 do not work correctly if you set the speed to 115200. If you have an old 8250 UART chip, it won't work. If you have a 16550 or 16550A it should work flawlessly.

Additionally, you should consult your modem manual to look for init strings that enable a high speed mode.

10.1.15. I get a REALLY slow connection speed!

If data drips on at a rate of just a few bytes per second, you should check your hardware setup. If moving your mouse speeds up the transmission this is definitely a hardware issue!

You can obtain some information about your serial port with `setserial `-a `/dev/ttySx``` and check for interrupt conflicts with other components of your system. The KDE Control Center module Information might also be of help here.

10.1.16. My phone line needs pulse dialling instead of tone dialling (or vice-versa). How do I change that?

You must modify your modem dial string. Nearly all modems support the following AT commands:

ATDT

  Selects tone dialling

ATDP

  Selects pulse dialling

### 2. Questions about Telephone Cost Rules

10.2.1. How do I write a telephones cost rules file?

Just follow the `TEMPLATE` rules file supplied with kppp. You should be able to find a copy in `$KDEDIR/doc/HTML/`yourlang`/kppp/`. Use the `-r` kppp command line option to check the syntax of your proposed rules file.

10.2.2. I have written a telephone cost rules for my region. Where can I submit it so that others can make use of it?

10.2.3. Can my phone cost rulefile contain fractional time units like "(0.17, 45.5)"?

Yes this is possible. But you shouldn't use unusually small time units below a tenth of a second, because this would result in higher CPU load, although you probably won't notice on a modern CPU.

10.2.4. My country observes other "moving" holidays than Easter.

In that case, you need to write new code that allows for the computation of that holiday. Please have a look at `ruleset.cpp` and emulate the "easter" example. Then send in the patches!.

### 3. Questions about the System Logs

10.3.1. I see a message saying Serial line is looped back. What does this mean?

Short answer: You didn't start the PPP software on the peer system.

10.3.2. The logs show Signal 15

If you see the following lines, you've probably just received a timeout error from kppp. kppp has been waiting for the PPP interface to come up and gave up after the specified timeout. pppd was signalled to shut down, with signal number 15, i.e. SIGTERM.

     pppd[26921]: pppd 2.3.5 started by me, uid 500
    pppd[26921]: Using interface ppp0
    pppd[26921]: Connect: ppp0 <--> /dev/ttyS0
    pppd[26921]: Terminating on signal 15.
    pppd[26921]: Connection terminated.
    pppd[26921]: Exit.

10.3.3. What about Receive serial link is not 8-bit clean

The PPP daemon is alarmed by the fact that all the data it receives has bit 8 set to zero. In most cases this simply indicates that the remote PPP server isn't running yet. You might still be confronted by a login prompt that echoes back all the data sent by your pppd.

10.3.4. and can't locate module ppp-compress? What's this?

Do you see the following messages?

     modprobe: can't locate module ppp-compress-21
    modprobe: can't locate module ppp-compress-26
    modprobe: can't locate module ppp-compress-24

Just add the lines:

     alias ppp-compress-21 bsd_comp
    alias ppp-compress-24 ppp_deflate
    alias ppp-compress-26 ppp_deflate

to your `/etc/conf.modules` file.

Prev | Home | Next
Windows® NT RAS callback |  | Credits and License