os/doc
3
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

Big update to the user PPP section

Browse source 
PR:	35105
Reviewed by:	jim
This commit is contained in:
Tom Rhodes 2002-04-04 23:32:50 +00:00
parent c5d02c8e89
commit cf84c89c6d
Notes: svn2git 2020-12-08 03:00:23 +00:00 
svn path=/head/; revision=12680
1 changed files with 214 additions and 109 deletions
Download patch file Download diff file Expand all files Collapse all files

323
en_US.ISO8859-1/books/handbook/ppp-and-slip/chapter.sgml
View file

@ -73,10 +73,10 @@
<itemizedlist>
<listitem>
<para>be familiar with basic network terminology.</para>
<para>Be familiar with basic network terminology.</para>
</listitem>
<listitem>
<para>understand the basics and purpose of a dialup connection
<para>Understand the basics and purpose of a dialup connection
and PPP and/or SLIP.</para>
</listitem>
</itemizedlist>
@ -101,6 +101,13 @@
<sect1 id="userppp">
<sect1info>
<authorgroup>
<author>
<firstname>Tom</firstname>
<surname>Rhodes</surname>
<contrib>Updated and enhanced by </contrib>
</author>
</authorgroup>
<authorgroup>
<author>
<firstname>Brian</firstname>
@ -186,8 +193,8 @@
Normally, you will be given two IP addresses by your ISP to
use for this. If they have not given you at least one, then
you can use the <command>enable dns</command> command in
your <filename>ppp.conf</filename> file to tell
<application>ppp</application> to set the name servers for
your <filename>ppp.conf</filename> file to have
<application>ppp</application> set the name servers for
you. This feature depends on your ISPs PPP implementation
supporting DNS negotiation.</para>
</listitem>
@ -228,7 +235,6 @@
<para>If you do not have any of the required information, contact
your ISP.</para>
<note>
<para>Throughout this section, many of the examples showing
the contents of configuration files are numbered by line.
@ -271,7 +277,7 @@
the existence of the <devicename>tun0</devicename> device should
be verified (this is not necessary if DEVFS is enabled as device
nodes will be created on demand).</para>
<para>The easiest way to make sure that the
<devicename>tun0</devicename> device is configured correctly
is to remake the device. To remake the device, do the
@ -286,137 +292,232 @@
<screen>&prompt.root; <userinput>cd /dev</userinput>
&prompt.root; <userinput>sh MAKEDEV tun15</userinput></screen>
</sect3>
<sect4>
<title>Check the Modem</title>
<para>If you reconfigured your <filename>kernel</filename>
then you should recall the <devicename>sio</devicename>
device. If your modem acts like a standard serial port
then you most likely only need to make the serial device.
You can do this by changing your directory to
<filename>/dev</filename> and running the <filename>MAKEDEV</filename>
script like above. Now make the serial device with
<screen>&prompt.root; <userinput>sh MAKEDEV cuaa</userinput></screen>
which will create the serial devices for your system.
If your modem is on <devicename>sio1</devicename> or
<acronym>COM2</acronym> if you are in dos, then your
modem device would be <devicename>/dev/cuaa1</devicename>.
</para>
</sect4>
</sect3>
<sect3>
<title>Name Resolution Configuration</title>
<title>Manual Connections</title>
<para>Connecting to the internet by manually controlling
<command>ppp</command> is quick, easy, and a great way
to debug a connection or just get information on how your
<acronym>ISP</acronym> handles connections. Lets start
<application>PPP</application> from the command line,
note that, in all of our examples we will use <emphasis>localhost</emphasis>
as the hostname of the machine running <application>PPP</application>.
You start <command>ppp</command> by just typing <command>ppp</command>:
<indexterm id="ppp-resolver">
<primary>resolver</primary>
</indexterm>
<indexterm id="ppp-hostname">
<primary><command>hostname</command></primary>
</indexterm>
<indexterm id="ppp-hosts">
<primary><filename>hosts</filename></primary>
</indexterm>
<para>The resolver is the part of the system that looks up IP
addresses into hostnames and vice versa. It can be configured
to look for maps that describe IP to hostname mappings in one of
two places. The first is a file called
<filename>/etc/hosts</filename>. Read &man.hosts.5; for more
information. The second is the Internet Domain Name Service
(DNS), a distributed data base. For more information on DNS
and DNS services, refer to <xref linkend="dns">.</para>
<screen>&prompt.root; <userinput>ppp</userinput></screen>
<para>The resolver is a set of system calls that perform the name
mappings, but you have to tell it where to find the
information. For versions of FreeBSD prior to 5.0. This is done by
editing the file <filename>/etc/host.conf</filename>.
FreeBSD 5.0 uses the <filename>/etc/nsswitch.conf</filename> file.</para>
<para>We have now started <command>ppp</command></para>
<sect4>
<title>Edit <filename>/etc/host.conf</filename></title>
<screen>ppp ON example&gt; set device <devicename>/dev/cuaa1</devicename></screen>
<para>For versions of FreeBSD prior to 5.0, this file should
contain the following two lines (in this order):</para>
<para>We set our modem device, in this case it is
<devicename>cuaa1</devicename></para>
<programlisting>hosts
bind</programlisting>
<screen>ppp ON example&gt; set speed 115200</screen>
<para>This instructs the resolver to first look in the file
<filename>/etc/hosts</filename>, and to then consult the DNS
if the name was not found.</para>
</sect4>
<para>Set the connection speed, in this case we
are using 115,200 <acronym>kbps</acronym></para>
<sect4>
<title>Edit <filename>/etc/nsswitch.conf</filename></title>
<screen>ppp ON example&gt; enable dns</screen>
<para>For FreeBSD version 5.0 or above, this file should
contain at least the following line:</para>
<para>Tell <command>ppp</command> to configure our
resolver and add the nameserver lines to
<filename>/etc/resolv.conf</filename>. If we <command>ppp</command>
cannot determine our hostname, we can set one manually later
</para>
<programlisting>hosts: files, dns</programlisting>
<screen>ppp ON example&gt; term</screen>
<para>This instructs the resolver to first look in the file
<filename>/etc/hosts</filename>, and to then consult DNS
if the name was not found.</para>
</sect4>
<sect4>
<title>Edit <filename>/etc/hosts</filename></title>
<para>Switch to "terminal" mode so that we can manually
control the modem</para>
<para>This file may contain the IP addresses and names of
machines on your local network. At a bare minimum it should
contain
entries for the machine which will be running ppp. Assuming
that your machine is called <hostid
role="fqdn">foo.example.com</hostid> with the IP address <hostid
role="ipaddr">10.0.0.1</hostid>,
<filename>/etc/hosts</filename> should contain:</para>
<programlisting>
deflink: Entering terminal mode on <devicename>/dev/cuaa1</devicename>
type '~h' for help</programlisting>
<programlisting>127.0.0.1 localhost.example.com localhost
::1 localhost.example.com localhost
10.0.0.1 foo.example.com foo</programlisting>
<screen><userinput>at</userinput>
OK
<userinput>atdt<replaceable>123456789</replaceable></userinput></screen>
<para>The first two lines define the alias
<hostid>localhost</hostid> as a synonym for the current
machine. Regardless of your own IP address, the IP addresses
for these lines should always be <hostid
role="ipaddr">127.0.0.1</hostid> and <hostid
role="ipaddr">::1</hostid>. The last line maps
the name <hostid role="fqdn">foo.example.com</hostid> (and the
shorthand <hostid>foo</hostid>) to the IP address <hostid
role="ipaddr">10.0.0.1</hostid>.</para>
<para>Use <command>at</command> to initialize the modem,
then use <command>atdt</command> and the number for your
<acronym>ISP</acronym> to begin the dial in process</para>
<note>
<para><hostid role="ipaddr">127.0.0.1</hostid> and
<hostid>localhost</hostid> are known as loopback
addresses, which loopback to the local machine.</para>
</note>
<screen>CONNECT</screen>
<para>If your provider allocates you a static IP address and
name, and you are not using that as your host name, add this
to the <filename>/etc/hosts</filename> too.</para>
</sect4>
<para>Confirmation of the connection, if we are going to have
any connection problems, unrelated to hardware, here is where
we will attempt to resolve them.</para>
<sect4>
<title>Edit <filename>/etc/resolv.conf</filename></title>
<screen>ISP Login:<userinput>myusername</userinput></screen>
<para>The <filename>/etc/resolv.conf</filename> file tells the
resolver how to behave. Normally, you will need to enter
the following line(s):</para>
<para>Here you are prompted for a username, return the
prompt with the username that was provided by the
<acronym>ISP</acronym></para>
<screen>ISP Pass:<userinput>mypassword</userinput></screen>
<para>This time we are prompted for a password, just
reply with the password that was provided by the
<acronym>ISP</acronym>. Just like when logging into
FreeBSD, the password will not echo.</para>
<screen>Shell or PPP:<userinput>ppp</userinput></screen>
<para>Depending on your <acronym>ISP</acronym> this prompt
may never appear. Here we are being asked if we wish to
use a shell on the provider, or to start
<command>ppp</command>. In this example, we have chosen
to use <command>ppp</command> as we want an internet
connection.</para>
<screen>Ppp ON example&gt;</screen>
<para>Notice that in this example the first <option>p</option>
has been capitalized. This shows that we have successfully
connected to the <acronym>ISP</acronym>.</para>
<screen>PPp ON example&gt;</screen>
<para>We have successfully authenticated with our
<acronym>ISP</acronym> and are waiting for the
assigned <acronym>IP</acronym> address.</para>
<screen>PPP ON example&gt;</screen>
<para>We have made an agreement on an <acronym>IP</acronym>
address and successfully completed our connection</para>
<screen>PPP ON example&gt;add default HISADDR</screen>
<para>Here we add our default route, we need to do this
before we can talk to the outside world as currently the
only established connection is with the peer. If this
fails due to existing routes you can put a bang character
<emphasis>!</emphasis> in front of the <option>add</option>.
Alternatively, you can set this before making the actual connection
and it will negotiate a new route accordingly.</para>
<para>If everything went good we should now have an active
connection to the internet, which could be thrown into
the background using
<keycombo action="simul"><keycap>CTRL</keycap> <keycap>z</keycap></keycombo>
If you notice the <command>PPP</command> return to
<command>ppp</command> then we have lost our connection.
This is good to know because it shows our connection status.
Capital P's show that we have a connection to the
<acronym>ISP</acronym> and lowercase p's show that the
connection has been lost for whatever reason.
<command>ppp</command> only has these 2 states.
</para>
<sect4>
<title>Troubleshooting Manual Connections</title>
<para>Like everything else, once in awhile a problem or
may occur. <application>PPP</application> is no
exemption to this theory. If <command>ppp</command>
would happen to stop responding there are some things
we can try.</para>
<para>If you have a direct line and cannot seem to make a
connection, then turn hardware flow <acronym>CTS/RTS</acronym>
to off with the <option>set ctsrts off</option>. This is
mainly the case if you are connected to some
<application>PPP</application> capable terminal servers,
where <application>PPP</application> hangs when it tries
to write data to your communication link, so it would
would be waiting for a <acronym>CTS</acronym>, or Clear
To Send signal which may never come. If you use this
option however, you should also use the <option>set accmap</option>
option, which may be required to defeat hardware dependent on
passing certain characters from end to end, most of the time
XON/XOFF. See the &man.ppp.8; man page for more information
on this option, and how it is used.</para>
<para>If you have an older modem, you may need to use the
<option>set parity even</option>. Parity is set at none
be default, but is used for error checking (with a large
increase in traffic) on older modems and some
<acronym>ISP</acronym>s. You may need this option for
the Compuserve ISP.</para>
<para><application>PPP</application> may not return to the
command mode, which is usually a negotiation error where
the <acronym>ISP</acronym> is waiting for your side to start
negotiating. At this point, using the <command>~p</command>
command will force ppp to start sending the configuration
information.</para>
<para>If you never obtain a login prompt, then most likely you
you need to use <acronym>PAP</acronym> or <acronym>CHAP</acronym>
authentication instead of the Unix-style in the example above. To
use <acronym>PAP</acronym> or <acronym>CHAP</acronym> just add the
following options to <application>PPP</application> before going
into terminal mode:</para>
<screen>ppp ON localhost&gt; <userinput>set authname <replaceable>myusername</replaceable></userinput></screen>
<para>Where <replaceable>myusername</replaceable> should be replaced with
the username that was assigned by the <acronym>ISP</acronym>.</para>
<screen>ppp ON localhost&gt; <userinput>set authkey <replaceable>mypassword</replaceable></userinput></screen>
<para>Where <replaceable>mypassword</replaceable> should be replaced with
the password that was assigned by the <acronym>ISP</acronym>.</para>
<para>If you connect fine, but cannot seem to find any domain name, try to
use &man.ping.8; with an <acronym>IP</acronym> address and see if you
can get any return information. If you experience 100 percent (100%)
packet loss, then its most likely that you were not assigned a default
route. Double check that the option <option>add default HISADDR</option>
was set during the connection. If you can connect to a remote
<acronym>IP</acronym> address then it is possible that a resolver address
has not been added to the <filename>/etc/resolv.conf</filename>. This
file should look like:</para>
<programlisting>domain <replaceable>example.com</replaceable>
nameserver <replaceable>x.x.x.x</replaceable>
nameserver <replaceable>y.y.y.y</replaceable></programlisting>
<para>The <hostid
role="ipaddr"><replaceable>x.x.x.x</replaceable></hostid> and
<hostid role="ipaddr"><replaceable>y.y.y.y</replaceable></hostid>
addresses are those given to you by your ISP. Add as many
<literal>nameserver</literal> lines as your ISP provides. The
<literal>domain</literal> line is set to your hosts
domain name. Refer to the &man.resolv.conf.5; manual page for
details of other possible entries in this file.</para>
<para>Where <replaceable>x.x.x.x</replaceable> and
<replaceable>y.y.y.y</replaceable> should be replaced with the
<acronym>IP</acronym> address of your <acronym>ISP</acronym>'s DNS servers.
This information may or may not have been provided when you signed up, but
a quick call to your <acronym>ISP</acronym> should remedy that.</para>
<para>If you are running a local name server, replace the
above nameserver lines with:</para>
<para>You could also have &man.syslog.3; provide a logging function
for your <application>PPP</application> connection. Just add:</para>
<programlisting>nameserver <replaceable>0.0.0.0</replaceable></programlisting>
<programlisting>
!ppp
*.* /var/log/ppp.log</programlisting>
<indexterm><primary>PPP</primary></indexterm>
<indexterm><primary>ISP</primary></indexterm>
<para>The <command>enable dns</command> command (entered in the
<filename>/etc/ppp/ppp.conf</filename> file - see below) will
tell PPP to request that your ISP confirms the nameserver values.
If your ISP supplies different addresses (or if there are no
nameserver lines in <filename>/etc/resolv.conf</filename>), PPP
will rewrite the file with the ISP-supplied values.</para>
</sect4>
<para>to <filename>/etc/syslog.conf</filename>. In most cases, this
functionality already exists.</para>
</sect4>
</sect3>
<sect3>
<title><application>PPP</application> Configuration</title>
<title>Automatic <application>PPP</application> Configuration</title>
<indexterm><primary>PPP</primary><secondary>configuration</secondary></indexterm>
<para>Both <command>ppp</command> and <command>pppd</command>
@ -444,7 +545,8 @@ nameserver <replaceable>y.y.y.y</replaceable></programlisting>
<para>Lines that end in a <literal>:</literal> start in
the first column (beginning of the line)&mdash; all other
lines should be indented as shown using spaces or
tabs.</para>
tabs. Most of the information you need to provide here
was shown to us by doing the manual dial above.</para>
</note>
<programlisting>1 default:
@ -574,7 +676,10 @@ nameserver <replaceable>y.y.y.y</replaceable></programlisting>
<listitem>
<para>Identifies an entry for a provider called
<quote>provider</quote>.</para>
<quote>provider</quote>. This could be changed
to the name of your <acronym>ISP</acronym> so
that later you can use the <option>load ISP</option>
to start the connection.</para>
</listitem>
</varlistentry>