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

Revert one of my previous changes. Sentences now have two spaces after

Browse source 
the period. Apologies for the repository bloat. This is entirely a
whitespace change.
This commit is contained in:
Nik Clayton 1999-03-04 22:42:55 +00:00
parent 772051fe94
commit fe79ecbe4d
Notes: svn2git 2020-12-08 03:00:23 +00:00 
svn path=/head/; revision=4465
88 changed files with 11040 additions and 11040 deletions
Download patch file Download diff file Expand all files Collapse all files

182
en/handbook/advanced-networking/chapter.sgml
View file

@ -10,13 +10,13 @@
<para>For one machine to be able to find another, there must be a
mechanism in place to describe how to get from one to the other.
This is called Routing. A &ldquo;route&rdquo; is a defined pair of addresses:
a &ldquo;destination&rdquo; and a &ldquo;gateway&rdquo;. The pair indicates that if you are
This is called Routing. A &ldquo;route&rdquo; is a defined pair of addresses:
a &ldquo;destination&rdquo; and a &ldquo;gateway&rdquo;. The pair indicates that if you are
trying to get to this <emphasis>destination</emphasis>, send along
through this <emphasis>gateway</emphasis>. There are three types of
destinations: individual hosts, subnets, and &ldquo;default&rdquo;. The
&ldquo;default route&rdquo; is used if none of the other routes apply. We will
talk a little bit more about default routes later on. There are
through this <emphasis>gateway</emphasis>. There are three types of
destinations: individual hosts, subnets, and &ldquo;default&rdquo;. The
&ldquo;default route&rdquo; is used if none of the other routes apply. We will
talk a little bit more about default routes later on. There are
also three types of gateways: individual hosts, interfaces (also
called &ldquo;links&rdquo;), and ethernet hardware addresses.</para>
@ -47,20 +47,20 @@ host2.foobar.com link#1 UC 0 0
<para>The interface (<literal>Netif</literal> column)
that it specifies to use for <literal>localhost</literal> is
<devicename>lo0</devicename>, also known as the loopback device. This
<devicename>lo0</devicename>, also known as the loopback device. This
says to keep all traffic for this destination internal, rather
than sending it out over the LAN, since it will only end up back
where it started anyway.</para>
<para>The next thing that stands out are the <hostid role="mac">0:e0:...</hostid> addresses. These are ethernet
hardware addresses. FreeBSD will automatically identify any hosts
<para>The next thing that stands out are the <hostid role="mac">0:e0:...</hostid> addresses. These are ethernet
hardware addresses. FreeBSD will automatically identify any hosts
(<hostid>test0</hostid> in the example) on the local
ethernet and add a route for that host, directly to it over the
ethernet interface, <devicename>ed0</devicename>. There is
ethernet interface, <devicename>ed0</devicename>. There is
also a timeout (<literal>Expire</literal> column)
associated with this type of route, which is used if we fail to
hear from the host in a specific amount of time. In this case the
route will be automatically deleted. These hosts are identified
hear from the host in a specific amount of time. In this case the
route will be automatically deleted. These hosts are identified
using a mechanism known as RIP (Routing Information Protocol),
which figures out routes to local hosts based upon a shortest path
determination.</para>
@ -69,28 +69,28 @@ host2.foobar.com link#1 UC 0 0
(<hostid role="ipaddr">10.20.30.255</hostid> is the broadcast
address for the subnet <hostid role="ipaddr">10.20.30</hostid>, and
<hostid role="domainname">foobar.com</hostid> is the domain name
associated with that subnet). The designation <literal>link#1</literal> refers to the first ethernet card in
the machine. You will notice no additional interface is specified
associated with that subnet). The designation <literal>link#1</literal> refers to the first ethernet card in
the machine. You will notice no additional interface is specified
for those.</para>
<para>Both of these groups (local network hosts and local subnets)
have their routes automatically configured by a daemon called
<command>routed</command>. If this is not run, then
<command>routed</command>. If this is not run, then
only routes which are statically defined (ie. entered explicitly)
will exist.</para>
<para>The <literal>host1</literal> line refers to our
host, which it knows by ethernet address. Since we are the
host, which it knows by ethernet address. Since we are the
sending host, FreeBSD knows to use the loopback interface
(<devicename>lo0</devicename>) rather than sending it out
over the ethernet interface.</para>
<para>The two <literal>host2</literal> lines are an
example of what happens when we use an ifconfig alias (see the
section of ethernet for reasons why we would do this). The
section of ethernet for reasons why we would do this). The
<literal>=&gt;</literal> symbol after the <devicename>lo0</devicename> interface says that not only are we
using the loopback (since this is address also refers to the local
host), but specifically it is an alias. Such routes only show up
host), but specifically it is an alias. Such routes only show up
on the host that supports the alias; all other hosts on the local
network will simply have a <literal>link#1</literal>
line for such.</para>
@ -98,8 +98,8 @@ host2.foobar.com link#1 UC 0 0
<para>The final line (destination subnet <literal>224</literal>) deals with MultiCasting, which will be
covered in a another section.</para>
<para>The other column that we should talk about are the <literal>Flags</literal>. Each route has different attributes
that are described in the column. Below is a short table of some
<para>The other column that we should talk about are the <literal>Flags</literal>. Each route has different attributes
that are described in the column. Below is a short table of some
of these flags and their meanings:</para>
@ -162,14 +162,14 @@ host2.foobar.com link#1 UC 0 0
<para>When the local system needs to make a connection to remote
host, it checks the routing table to determine if a known path
exists. If the remote host falls into a subnet that we know how to
exists. If the remote host falls into a subnet that we know how to
reach (Cloned routes), then the system checks to see if it can
connect along that interface.</para>
<para>If all known paths fail, the system has one last option: the
&ldquo;default&rdquo; route. This route is a
&ldquo;default&rdquo; route. This route is a
special type of gateway route (usually the only one present in the
system), and is always marked with a <literal>c</literal> in the flags field. For hosts on a
system), and is always marked with a <literal>c</literal> in the flags field. For hosts on a
local area network, this gateway is set to whatever machine has a
direct connection to the outside world (whether via PPP link, or
your hardware device attached to a dedicated data line).</para>
@ -179,7 +179,7 @@ host2.foobar.com link#1 UC 0 0
the default route will be the gateway machine at your Internet
Service Provider's (ISP) site.</para>
<para>Let us look at an example of default routes. This is a common
<para>Let us look at an example of default routes. This is a common
configuration:</para>
<literallayout>
@ -187,7 +187,7 @@ host2.foobar.com link#1 UC 0 0
</literallayout>
<para>The hosts <hostid>Local1</hostid> and <hostid>Local2</hostid> are at your site, with the formed
being your PPP connection to your ISP's Terminal Server. Your ISP
being your PPP connection to your ISP's Terminal Server. Your ISP
has a local network at their site, which has, among other things,
the server where you connect and a hardware device (T1-GW)
attached to the ISP's Internet feed.</para>
@ -227,13 +227,13 @@ host2.foobar.com link#1 UC 0 0
<para>Remember, since the PPP interface is using an address on the
ISP's local network for your side of the connection, routes for
any other machines on the ISP's local network will be
automatically generated. Hence, you will already know how to reach
automatically generated. Hence, you will already know how to reach
the T1-GW machine, so there is no need for the intermediate step
of sending traffic to the ISP server.</para>
<para>As a final note, it is common to use the address <hostid
role="ipaddr">...1</hostid> as the gateway address for your local
network. So (using the same example), if your local class-C
network. So (using the same example), if your local class-C
address space was <hostid role="ipaddr">10.20.30</hostid> and your
ISP was using <hostid role="ipaddr">10.9.9</hostid> then the
default routes would be:</para>
@ -251,20 +251,20 @@ Local1 (10.20.30.1, 10.9.9.30) --&gt; T1-GW (10.9.9.1)
<para>There is one other type of configuration that we should cover,
and that is a host that sits on two different networks.
Technically, any machine functioning as a gateway (in the example
above, using a PPP connection) counts as a dual-homed host. But
above, using a PPP connection) counts as a dual-homed host. But
the term is really only used to refer to a machine that sits on
two local-area networks.</para>
<para>In one case, the machine as two ethernet cards, each having an
address on the separate subnets. Alternately, the machine may only
have one ethernet card, and be using ifconfig aliasing. The former
address on the separate subnets. Alternately, the machine may only
have one ethernet card, and be using ifconfig aliasing. The former
is used if two physically separate ethernet networks are in use,
the latter if there is one physical network segment, but two
logically separate subnets.</para>
<para>Either way, routing tables are set up so that each subnet
knows that this machine is the defined gateway (inbound route) to
the other subnet. This configuration, with the machine acting as
the other subnet. This configuration, with the machine acting as
a Bridge between the two subnets, is often used when we need to
implement packet filtering or firewall security in either or both
directions.</para>
@ -286,21 +286,21 @@ Local1 (10.20.30.1, 10.9.9.30) --&gt; T1-GW (10.9.9.1)
<para>When you get an address space assigned to your site, your
service provider will set up their routing tables so that all
traffic for your subnet will be sent down your PPP link to your
site. But how do sites across the country know to send to your
site. But how do sites across the country know to send to your
ISP?</para>
<para>There is a system (much like the distributed DNS information)
that keeps track of all assigned address-spaces, and defines their
point of connection to the Internet Backbone. The &ldquo;Backbone&rdquo; are
point of connection to the Internet Backbone. The &ldquo;Backbone&rdquo; are
the main trunk lines that carry Internet traffic across the
country, and around the world. Each backbone machine has a copy of
country, and around the world. Each backbone machine has a copy of
a master set of tables, which direct traffic for a particular
network to a specific backbone carrier, and from there down the
chain of service providers until it reaches your network.</para>
<para>It is the task of your service provider to advertise to the
backbone sites that they are the point of connection (and thus the
path inward) for your site. This is known as route
path inward) for your site. This is known as route
propagation.</para>
</sect2>
@ -309,14 +309,14 @@ Local1 (10.20.30.1, 10.9.9.30) --&gt; T1-GW (10.9.9.1)
<title>Troubleshooting</title>
<para>Sometimes, there is a problem with routing propagation, and
some sites are unable to connect to you. Perhaps the most useful
some sites are unable to connect to you. Perhaps the most useful
command for trying to figure out where a routing is breaking down
is the <citerefentry><refentrytitle>traceroute</refentrytitle><manvolnum>8</manvolnum></citerefentry> command. It is equally
is the <citerefentry><refentrytitle>traceroute</refentrytitle><manvolnum>8</manvolnum></citerefentry> command. It is equally
useful if you cannot seem to make a connection to a remote machine
(ie. <citerefentry><refentrytitle>ping</refentrytitle><manvolnum>8</manvolnum></citerefentry> fails).</para>
(ie. <citerefentry><refentrytitle>ping</refentrytitle><manvolnum>8</manvolnum></citerefentry> fails).</para>
<para>The <citerefentry><refentrytitle>traceroute</refentrytitle><manvolnum>8</manvolnum></citerefentry> command is run with the
name of the remote host you are trying to connect to. It will show
name of the remote host you are trying to connect to. It will show
the gateway hosts along the path of the attempt, eventually either
reaching the target host, or terminating because of a lack of
connection.</para>
@ -339,38 +339,38 @@ Local1 (10.20.30.1, 10.9.9.30) --&gt; T1-GW (10.9.9.1)
<para>The problem nearly always occurs when (FreeBSD) PC systems are
networked with high-performance workstations, such as those made by
Silicon Graphics, Inc., and Sun Microsystems, Inc. The NFS mount
Silicon Graphics, Inc., and Sun Microsystems, Inc. The NFS mount
will work fine, and some operations may succeed, but suddenly the
server will seem to become unresponsive to the client, even though
requests to and from other systems continue to be processed. This
requests to and from other systems continue to be processed. This
happens to the client system, whether the client is the FreeBSD
system or the workstation. On many systems, there is no way to shut
system or the workstation. On many systems, there is no way to shut
down the client gracefully once this problem has manifested itself.
The only solution is often to reset the client, because the NFS
situation cannot be resolved.</para>
<para>Though the &ldquo;correct&rdquo; solution is to get a higher performance and
capacity Ethernet adapter for the FreeBSD system, there is a simple
workaround that will allow satisfactory operation. If the FreeBSD
workaround that will allow satisfactory operation. If the FreeBSD
system is the <emphasis>server</emphasis>, include the option <option>-w=1024</option> on the mount from
the client. If the FreeBSD system is the <emphasis>client</emphasis>, then mount the NFS
file system with the option <option>-r=1024</option>. These options may be
the client. If the FreeBSD system is the <emphasis>client</emphasis>, then mount the NFS
file system with the option <option>-r=1024</option>. These options may be
specified using the fourth field of the <filename>fstab</filename> entry on the client
for automatic mounts, or by using the <option>-o</option> parameter of the mount
command for manual mounts.</para>
<para>It should be noted that there is a different problem, sometimes
mistaken for this one, when the NFS servers and clients are on
different networks. If that is the case, make <emphasis>certain</emphasis> that your
different networks. If that is the case, make <emphasis>certain</emphasis> that your
routers are routing the necessary UDP information, or you will not
get anywhere, no matter what else you are doing.</para>
<para>In the following examples, <hostid>fastws</hostid> is the host (interface) name
of a high-performance workstation, and <hostid>freebox</hostid> is the host
(interface) name of a FreeBSD system with a lower-performance
Ethernet adapter. Also, <filename>/sharedfs</filename> will be the exported NFS
Ethernet adapter. Also, <filename>/sharedfs</filename> will be the exported NFS
filesystem (see <command>man exports</command>), and <filename>/project</filename> will be the mount
point on the client for the exported file system. In all cases,
point on the client for the exported file system. In all cases,
note that additional options, such as <option>hard</option> or <option>soft</option> and <option>bg</option> may
be desirable in your application.</para>
@ -402,18 +402,18 @@ freebox:/sharedfs /project nfs rw,-w=1024 0 0</programlisting>
the above restrictions on the read or write size.</para>
<para>For anyone who cares, here is what happens when the failure
occurs, which also explains why it is unrecoverable. NFS typically
occurs, which also explains why it is unrecoverable. NFS typically
works with a &ldquo;block&rdquo; size of 8k (though it may do fragments of
smaller sizes). Since the maximum Ethernet packet is around 1500
smaller sizes). Since the maximum Ethernet packet is around 1500
bytes, the NFS &ldquo;block&rdquo; gets split into multiple Ethernet packets,
even though it is still a single unit to the upper-level code, and
must be received, assembled, and <emphasis>acknowledged</emphasis> as a unit. The
must be received, assembled, and <emphasis>acknowledged</emphasis> as a unit. The
high-performance workstations can pump out the packets which
comprise the NFS unit one right after the other, just as close
together as the standard allows. On the smaller, lower capacity
together as the standard allows. On the smaller, lower capacity
cards, the later packets overrun the earlier packets of the same
unit before they can be transferred to the host and the unit as a
whole cannot be reconstructed or acknowledged. As a result, the
whole cannot be reconstructed or acknowledged. As a result, the
workstation will time out and try again, but it will try again with
the entire 8K unit, and the process will be repeated, ad
infinitum.</para>
@ -425,7 +425,7 @@ freebox:/sharedfs /project nfs rw,-w=1024 0 0</programlisting>
<para>Overruns may still occur when a high-performance workstations is
slamming data out to a PC system, but with the better cards, such
overruns are not guaranteed on NFS &ldquo;units&rdquo;. When an overrun occurs,
overruns are not guaranteed on NFS &ldquo;units&rdquo;. When an overrun occurs,
the units affected will be retransmitted, and there will be a fair
chance that they will be received, assembled, and acknowledged.</para>
@ -438,8 +438,8 @@ freebox:/sharedfs /project nfs rw,-w=1024 0 0</programlisting>
<para><filename>netboot.com</filename>/<filename>netboot.rom</filename> allow you to boot
your FreeBSD machine over the network and run FreeBSD without having
a disk on your client. Under 2.0 it is now possible to have local
swap. Swapping over NFS is also still supported.</para>
a disk on your client. Under 2.0 it is now possible to have local
swap. Swapping over NFS is also still supported.</para>
<para>Supported Ethernet cards include: Western Digital/SMC 8003,
8013, 8216 and compatibles; NE1000/NE2000 and compatibles (requires
@ -453,7 +453,7 @@ freebox:/sharedfs /project nfs rw,-w=1024 0 0</programlisting>
<procedure>
<step>
<para>Find a machine that will be your server. This machine
<para>Find a machine that will be your server. This machine
will require enough disk space to hold the FreeBSD 2.0
binaries and have bootp, tftp and NFS services available.
Tested machines:</para>
@ -466,7 +466,7 @@ freebox:/sharedfs /project nfs rw,-w=1024 0 0</programlisting>
</listitem>
<listitem>
<para>Sun/Solaris 2.3. (you may need to get
<para>Sun/Solaris 2.3. (you may need to get
bootp)</para>
</listitem>
@ -492,12 +492,12 @@ diskless:\
<step>
<para>Set up a TFTP server (on same machine as bootp server)
to provide booting information to client. The name of this
to provide booting information to client. The name of this
file is <filename>cfg.<replaceable>X.X.X.X</replaceable></filename> (or
<filename>/tftpboot/cfg.<replaceable>X.X.X.X</replaceable></filename>, it will try
both) where <replaceable>X.X.X.X</replaceable> is the IP address
of the client. The contents of this file can be any valid
netboot commands. Under 2.0, netboot has the following
of the client. The contents of this file can be any valid
netboot commands. Under 2.0, netboot has the following
commands:</para>
<informaltable frame="none">
@ -611,7 +611,7 @@ hostname myclient.mydomain</programlisting>
<step>
<para>If you are swapping over NFS (completely diskless
configuration) create a swap file for your client using
<command>dd</command>. If your <command>swapfs</command> command has the arguments
<command>dd</command>. If your <command>swapfs</command> command has the arguments
<filename>/swapfs</filename> and the size 20000 as in the
example above, the swapfile for myclient will be called
<filename>/swapfs/swap.<replaceable>X.X.X.X</replaceable></filename> where
@ -650,7 +650,7 @@ hostname myclient.mydomain</programlisting>
<para>When extracting <filename>/dev</filename> in
<filename>/rootfs/myclient</filename>, beware that
some systems (HPUX) will not create device files that
FreeBSD is happy with. You may have to go to single
FreeBSD is happy with. You may have to go to single
user mode on the first bootup (press control-c during
the bootup phase), cd <filename>/dev</filename> and do
a <command>sh ./MAKEDEV all</command>
@ -679,7 +679,7 @@ hostname myclient.mydomain</programlisting>
<para>At present there isn't an officially sanctioned way of doing
this, although I have been using a shared
<filename>/usr</filename> filesystem and individual
<filename>/</filename> filesystems for each client. If anyone has
<filename>/</filename> filesystems for each client. If anyone has
any suggestions on how to do this cleanly, please let me and/or
the &a.core; know.</para>
@ -690,7 +690,7 @@ hostname myclient.mydomain</programlisting>
<para>Netboot can be compiled to support NE1000/2000 cards by
changing the configuration in
<filename>/sys/i386/boot/netboot/Makefile</filename>. See the
<filename>/sys/i386/boot/netboot/Makefile</filename>. See the
comments at the top of this file.</para>
</sect2>
@ -718,7 +718,7 @@ hostname myclient.mydomain</programlisting>
<para>If you are planning to use ISDN primarily to connect to
the Internet with an Internet Provider on a dialup
non-dedicated basis, I suggest you look into Terminal
Adapters. This will give you the most flexibility, with the
Adapters. This will give you the most flexibility, with the
fewest problems, if you change providers.</para>
</listitem>
@ -731,7 +731,7 @@ hostname myclient.mydomain</programlisting>
</itemizedlist>
<para>Cost is a significant factor in determining what solution you
will choose. The following options are listed from least expensive
will choose. The following options are listed from least expensive
to most expensive.</para>
@ -741,10 +741,10 @@ hostname myclient.mydomain</programlisting>
<para><emphasis>Contributed by &a.hm;.</emphasis></para>
<para>This section is really only relevant to ISDN users in countries
where the DSS1/Q.931 ISDN standard is supported. </para>
where the DSS1/Q.931 ISDN standard is supported.</para>
<para>Some growing number of PC ISDN cards are supported under FreeBSD
2.2.x and up by the isdn4bsd driver package. It is still under
2.2.x and up by the isdn4bsd driver package. It is still under
development but the reports show that it is successfully used all
over Europe.</para>
@ -753,17 +753,17 @@ hostname myclient.mydomain</programlisting>
the main isdn4bsd ftp site (you have to log in as user
<username>isdn4bsd</username> , give your mail address as the
password and change to the <filename>pub</filename>
directory. Anonymous ftp as user <username>ftp</username> or
directory. Anonymous ftp as user <username>ftp</username> or
<username>anonymous</username> will <emphasis>not</emphasis> give
the desired result).</para>
<para>Isdn4bsd allows you to connect to other ISDN routers using
either IP over raw HDLC or by using synchronous PPP. A telephone
either IP over raw HDLC or by using synchronous PPP. A telephone
answering machine application is also available.</para>
<para>Many ISDN PC cards are supported, mostly the ones with a Siemens
ISDN chipset (ISAC/HSCX), support for other chipsets (from Motorola,
Cologne Chip Designs) is currently under development. For an
Cologne Chip Designs) is currently under development. For an
up-to-date list of supported cards, please have a look at the
<ulink url="ftp://isdn4bsd@ftp.consol.de/pub/README">README</ulink>
file.</para>
@ -773,7 +773,7 @@ hostname myclient.mydomain</programlisting>
enhancing isdn4bsd, please get in touch with
<email>hm@kts.org</email>.</para>
<para>A majordomo maintained mailing list is available. To join the
<para>A majordomo maintained mailing list is available. To join the
list, send mail to <email>majordomo@FreeBSD.ORG</email> and
specify:</para>
@ -794,21 +794,21 @@ subscribe freebsd-isdn</programlisting>
<para>A TA will operate basically the same as a modem except
connection and throughput speeds will be much faster than your old
modem. You will need to configure <link linkend="ppp">PPP</link>
modem. You will need to configure <link linkend="ppp">PPP</link>
exactly the
same as for a modem setup. Make sure you set your serial speed as
same as for a modem setup. Make sure you set your serial speed as
high as possible.</para>
<para>The main advantage of using a TA to connect to an Internet
Provider is that you can do Dynamic PPP. As IP address space
Provider is that you can do Dynamic PPP. As IP address space
becomes more and more scarce, most providers are not willing to
provide you with a static IP anymore. Most standalone routers are
provide you with a static IP anymore. Most standalone routers are
not able to accommodate dynamic IP allocation.</para>
<para>TA's completely rely on the PPP daemon that you are running
for their features and stability of connection. This allows you
for their features and stability of connection. This allows you
to upgrade easily from using a modem to ISDN on a FreeBSD machine,
if you already have PPP setup. However, at the same time any
if you already have PPP setup. However, at the same time any
problems you experienced with the PPP program and are going to
persist.</para>
@ -850,8 +850,8 @@ subscribe freebsd-isdn</programlisting>
the TA to a synchronous serial card.</para>
<para>Do not be fooled into buying an internal TA and thinking you
have avoided the synchronous/asynchronous issue. Internal TA's
simply have a standard PC serial port chip built into them. All
have avoided the synchronous/asynchronous issue. Internal TA's
simply have a standard PC serial port chip built into them. All
this will do, is save you having to buy another serial cable, and
find another empty electrical socket.</para>
@ -860,8 +860,8 @@ subscribe freebsd-isdn</programlisting>
probably more flexible.</para>
<para>The choice of sync/TA vs standalone router is largely a
religious issue. There has been some discussion of this in the
mailing lists. I suggest you search the <ulink
religious issue. There has been some discussion of this in the
mailing lists. I suggest you search the <ulink
URL="http://www.freebsd.org/search.html">archives</ulink> for
the complete discussion.</para>
@ -871,7 +871,7 @@ subscribe freebsd-isdn</programlisting>
<title>Standalone ISDN Bridges/Routers</title>
<para>ISDN bridges or routers are not at all specific to FreeBSD or
any other operating system. For a more complete description of
any other operating system. For a more complete description of
routing and bridging technology, please refer to a Networking
reference book.</para>
@ -879,10 +879,10 @@ subscribe freebsd-isdn</programlisting>
interchangeably.</para>
<para>As the cost of low end ISDN routers/bridges comes down, it
will likely become a more and more popular choice. An ISDN router
will likely become a more and more popular choice. An ISDN router
is a small box that plugs directly into your local Ethernet
network(or card), and manages its own connection to the other
bridge/router. It has all the software to do PPP and other
bridge/router. It has all the software to do PPP and other
protocols built in.</para>
<para>A router will allow you much faster throughput that a standard
@ -890,13 +890,13 @@ subscribe freebsd-isdn</programlisting>
connection.</para>
<para>The main problem with ISDN routers and bridges is that
interoperability between manufacturers can still be a problem. If
interoperability between manufacturers can still be a problem. If
you are planning to connect to an Internet provider, I recommend
that you discuss your needs with them.</para>
<para>If you are planning to connect two lan segments together, ie:
home lan to the office lan, this is the simplest lowest
maintenance solution. Since you are buying the equipment for both
maintenance solution. Since you are buying the equipment for both
sides of the connection you can be assured that the link will
work.</para>
@ -907,7 +907,7 @@ subscribe freebsd-isdn</programlisting>
<example>
<title>Branch office or Home network</title>
<para>Network is 10 Base T Ethernet. Connect router to network
<para>Network is 10 Base T Ethernet. Connect router to network
cable with AUI/10BT transceiver, if necessary.</para>
<!-- This should be a graphic -->
@ -949,7 +949,7 @@ ISDN BRI line</programlisting>
<para>One large advantage of most routers/bridges is that they allow
you to have 2 <emphasis>separate independent</emphasis> PPP connections to 2 separate
sites at the <emphasis>same</emphasis> time. This is not supported on most TA's,
sites at the <emphasis>same</emphasis> time. This is not supported on most TA's,
except for specific(expensive) models that have two serial ports.
Do not confuse this with channel bonding, MPP etc.</para>
@ -958,7 +958,7 @@ ISDN BRI line</programlisting>
to tap into it, but don't want to get another ISDN line at work.
A router at the office location can manage a dedicated B channel
connection (64Kbs) to the internet, as well as a use the other B
channel for a separate data connection. The second B channel can
channel for a separate data connection. The second B channel can
be used for dialin, dialout or dynamically bond(MPP etc.) with the
first B channel for more bandwidth.</para>