25.6. Using PPP over ATM (PPPoA)

The following describes how to set up PPP over ATM (PPPoA). PPPoA is a popular choice among European DSL providers.

25.6.1. Using PPPoA with the Alcatel SpeedTouch™ USB

PPPoA support for this device is supplied as a port in FreeBSD because the firmware is distributed under Alcatel's license agreement and can not be redistributed freely with the base system of FreeBSD.

To install the software, simply use the Ports Collection. Install the net/pppoa port and follow the instructions provided with it.

Like many USB devices, the Alcatel SpeedTouch™ USB needs to download firmware from the host computer to operate properly. It is possible to automate this process in FreeBSD so that this transfer takes place whenever the device is plugged into a USB port. The following information can be added to the /etc/usbd.conf file to enable this automatic firmware transfer. This file must be edited as the root user.

device "Alcatel SpeedTouch USB"
    devname "ugen[0-9]+"
    vendor 0x06b9
    product 0x4061
    attach "/usr/local/sbin/modem_run -f /usr/local/libdata/mgmt.o"

To enable the USB daemon, usbd, put the following the line into /etc/rc.conf:

usbd_enable="YES"

It is also possible to set up ppp to dial up at startup. To do this add the following lines to /etc/rc.conf. Again, for this procedure you will need to be logged in as the root user.

ppp_enable="YES"
ppp_mode="ddial"
ppp_profile="adsl"

For this to work correctly you will need to have used the sample ppp.conf which is supplied with the net/pppoa port.

25.6.2. Using mpd

You can use mpd to connect to a variety of services, in particular PPTP services. You can find mpd in the Ports Collection, net/mpd. Many ADSL modems require that a PPTP tunnel is created between the modem and computer, one such modem is the Alcatel SpeedTouch™ Home.

First you must install the port, and then you can configure mpd to suit your requirements and provider settings. The port places a set of sample configuration files which are well documented in PREFIX/etc/mpd/. Note here that PREFIX means the directory into which your ports are installed, this defaults to /usr/local/. A complete guide to configure mpd is available in HTML format once the port has been installed. It is placed in PREFIX/share/doc/mpd/. Here is a sample configuration for connecting to an ADSL service with mpd. The configuration is spread over two files, first the mpd.conf:

default:
    load adsl

adsl:
    new -i ng0 adsl adsl
    set bundle authname username 1
    set bundle password password 2
    set bundle disable multilink

    set link no pap acfcomp protocomp
    set link disable chap
    set link accept chap
    set link keep-alive 30 10

    set ipcp no vjcomp
    set ipcp ranges 0.0.0.0/0 0.0.0.0/0

    set iface route default
    set iface disable on-demand
    set iface enable proxy-arp
    set iface idle 0

    open

1

The username used to authenticate with your ISP.

2

The password used to authenticate with your ISP.

The mpd.links file contains information about the link, or links, you wish to establish. An example mpd.links to accompany the above example is given beneath:

adsl:
    set link type pptp
    set pptp mode active
    set pptp enable originate outcall
    set pptp self 10.0.0.1 1
    set pptp peer 10.0.0.138 2

1

The IP address of your FreeBSD computer which you will be using mpd from.

2

The IP address of your ADSL modem. For the Alcatel SpeedTouch™ Home this address defaults to 10.0.0.138.

It is possible to initialize the connection easily by issuing the following command as root:

# mpd -b adsl

You can see the status of the connection with the following command:

% ifconfig ng0
ng0: flags=88d1<UP,POINTOPOINT,RUNNING,NOARP,SIMPLEX,MULTICAST> mtu 1500
     inet 216.136.204.117 --> 204.152.186.171 netmask 0xffffffff

Using mpd is the recommended way to connect to an ADSL service with FreeBSD.

25.6.3. Using pptpclient

It is also possible to use FreeBSD to connect to other PPPoA services using net/pptpclient.

To use net/pptpclient to connect to a DSL service, install the port or package and edit your /etc/ppp/ppp.conf. You will need to be root to perform both of these operations. An example section of ppp.conf is given below. For further information on ppp.conf options consult the ppp manual page, ppp(8).

adsl:
 set log phase chat lcp ipcp ccp tun command
 set timeout 0
 enable dns
 set authname username 1
 set authkey password 2
 set ifaddr 0 0
 add default HISADDR

1

The username of your account with the DSL provider.

2

The password for your account.

警告:

Because you must put your account's password in the ppp.conf file in plain text form you should make sure than nobody can read the contents of this file. The following series of commands will make sure the file is only readable by the root account. Refer to the manual pages for chmod(1) and chown(8) for further information.

# chown root:wheel /etc/ppp/ppp.conf
# chmod 600 /etc/ppp/ppp.conf

This will open a tunnel for a PPP session to your DSL router. Ethernet DSL modems have a preconfigured LAN IP address which you connect to. In the case of the Alcatel SpeedTouch™ Home this address is 10.0.0.138. Your router documentation should tell you which address your device uses. To open the tunnel and start a PPP session execute the following command:

# pptp address adsl

提示:

You may wish to add an ampersand (&) to the end of the previous command because pptp will not return your prompt to you otherwise.

A tun virtual tunnel device will be created for interaction between the pptp and ppp processes. Once you have been returned to your prompt, or the pptp process has confirmed a connection you can examine the tunnel like so:

% ifconfig tun0
tun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1500
        inet 216.136.204.21 --> 204.152.186.171 netmask 0xffffff00
        Opened by PID 918

If you are unable to connect, check the configuration of your router, which is usually accessible via telnet or with a web browser. If you still cannot connect you should examine the output of the pptp command and the contents of the ppp log file, /var/log/ppp.log for clues.

All FreeBSD documents are available for download at http://ftp.FreeBSD.org/pub/FreeBSD/doc/

Questions that are not answered by the documentation may be sent to <freebsd-questions@FreeBSD.org>.
Send questions about this document to <freebsd-doc@FreeBSD.org>.