Connecting to the Internet by fionan


									2 April 2003, 17:00:47 The Complete FreeBSD (, page 315

    In this chapter:
    • The physical

    • Establishing yourself
         on the Internet
    • Choosing an Internet
         Service Provider
    • Who’s that ISP?
    • Making the

                                                        Connecting to the

To implement the reference network shown in the previous chapter, we need to do a lot of
things that interface with the outside world. They can take some time, so we should look
at them first:
•     What kind of physical connection should we use? We’ll consider that in the next
•     We may want to register a domain. Many people don’t, but I strongly recommend it.
      Find out about that on page 317.
•     We may also want to register a network. In our example, we have used the network In real life, we can’t choose our own network: we take what is given
      to us. We’ll look at this on page 318.
•     We need to find an Internet Service Provider. We’ll look at what that entails on page

The physical connection
Just two or three years ago, the way to connect to the outside world was simple: a phone
line. Since then, things have changed quite a bit, and you may have quite a choice:
•     Analogue telephone line connections are still the most common way of connecting
      small networks in most countries, but their bandwidth is limited to about 7 kB/s at,v v4.10 (2003/04/02 03:09:55)                                                   315
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The physical connection                                                                                       316

     best. You can run PPP or SLIP over this kind of line, though nowadays most ISPs
     support only PPP.
•    ISDN stands for Integrated Systems Digital Network. It’s the new, better, washes-
     whiter telephone system that is replacing POTS (Plain Old Telephone Service) in
     some countries, notably in Europe. FreeBSD supports ISDN with the isdn4bsd
     driver. We won’t look at ISDN further in this book.
•    Leased lines form the backbone of the Internet. They’re invariably more expensive
     than dialup lines, but they can provide quite high speeds—in the USA, a T1 line will
     give you 1,536 kbps, and in the rest of the world an E1 will give you 2,048 kbps.
     Leased lines are becoming less interesting, and we won’t look at them in more detail
     in this book.
•    Cable modems use existing cable TV networks to deliver a high speed connection, up
     to several megabits per second. They use the cable as a broadcast medium, rather like
     an Ethernet, and suffer from the same load problems: you share the speed with the
     other users of the cable. There are also some security issues to consider, but if you
     have a cable service in your area, you’ll probably find it superior to telephones. The
     cable modem is effectively a bridge between the cable and an Ethernet. From the
     FreeBSD point of view, the cable modem looks like just another Ethernet device.
•    DSL (Digital Subscriber Line) is the telephone companies’ reaction to cable modems.
             Until recently, the L stood for Loop, not Line. A loop is the telco term for the pair of wires
             between the exchange (or Central Office) and the subscriber premises.

     There are a number of variants on DSL: ADSL (Asynchronous Digital Subscriber
     Line) has different speeds for the uplink and the downlink, while SDSL (Symmetric
     Digital Subscriber Line) and HDSL (High-speed Digital Subscriber Line) have the
     same speed in each direction. Speeds and capabilities differ widely from one location
     to another. By modifying the way they transmit data over normal phone wires,
     including the use of special modems, ADSL can get speeds of up to 6 Mb/s
     downstream (towards the end user), and about 640 kbps upstream. HDSL has similar
     speeds, but the speed is the same in each direction. In contrast to cable modems, you
     don’t have to share this bandwidth with anybody. Technical considerations limit the
     loop length to about four miles, so even in big cities you may not be able to get it.
     Many DSL services are plagued by technical problems. There are a number of
     different ways to connect to a DSL service, but most of them involve a conversion to
•    In some parts of the world, satellite connections are a viable alternative. These
     usually use a telephone line for outgoing data and a satellite receiver for incoming
     data. Pricing varies from very cheap to quite expensive, but if you can’t get cable or
     DSL, this might be your only choice.

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317                                                                        Chapter 18: Connecting to the Internet

Establishing yourself on the Internet
The first thing you need to decide is the extent of your presence on the Net. There are
various possibilities:
•     You could get a dialup service where you use your computer just to connect to the
      ISP, and perform network functions such as reading mail and news on the ISP’s
      machine (a shell account). It’s a lot faster to perform these functions on your own
      machine, and you have all the software you need to do so, so this option isn’t very
      desirable. This option is becoming increasingly uncommon.
•     You could perform all the functions on your machine, but using names and addresses
      assigned to you by the ISP.
•     You could perform all the functions on your machine, using addresses assigned to
      you by the ISP, but you would use your own domain name.
•     You get your own address space and use your own domain name.
Does it matter? That’s for you to decide. It’s certainly a very good idea to have your own
domain name. As time goes on, your email address will become more and more
important. If you get a mail address like, and Flybynight goes
broke, or you decide to change to a different ISP, your mail address is gone, and you have
to explain that to everybody who might want to contact you. If, on the other hand, your
name is Jerry Dunham, and you register a domain, you can assign yourself
any mail address in that domain.
But how do you go about it? One way would be to pay your ISP to do it for you. You
don’t need to do that: it’s easy enough to do yourself on the World-Wide Web. You must
be connected to the Internet to perform these steps. This implies that you should first
connect using your ISP’s domain name, then establish your domain name, and change to
that domain.

Which domain name?
We’ll continue to assume that your name is Jerry Dunham. If you live in, say, Austin,
Texas, you have a number of domain names you can choose from:,,, or even if you want to use the geographical
If you live in, say, Capetown, people will probably suggest that you get the domain, the geographical domain for South Africa. The problem with that is that
you are limiting yourself to that country. If you move to, say, Holland, you would have to
change to—a situation only fractionally better than being bound to an ISP.
The same considerations apply to, of course.
Your choice of domain name also affects the way you apply. In the following sections, I
assume you take my advice and apply for an organizational rather than a geographical
domain.,v v4.10 (2003/04/02 03:09:55)
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Establishing yourself on the Internet                                                                      318

Preparing for registration
Once upon a time, registration was handled by InterNIC, a professional body. Since then
it has been delegated to commercial companies, and the quality of service has suffered
correspondingly: they don’t even appear to know the technical terms. For example, you
may find them referring to a domain name as a ‘‘Web Address.’’ Things are still
deteriorating at the time of writing: additional companies are being allowed to register
domain names, and the field seems to attract a lot of cowboys.

Registering a domain name
The only prerequisites for registering a domain name are:
•     The name must be available, though there are some legal implications that suggest
      that, though you might be able to register a domain such as, it might
      not be good for you if you do. In fact, was once registered to the
      BISPL business school in Hyderabad, India, presumably not in agreement with
•     You must be able to specify two name servers for it—see Chapter 21 for further
      details about name servers.
First, check that the name is available:

    $ whois
    No match for "DUNHAM.ORG".

    The InterNIC Registration Services Host contains ONLY Internet Information
    (Networks, ASN’s, Domains, and POC’s).
    Please use the whois server at for MILNET Information.

Next, try to find a reputable registrar. Immediately after the transfer of registrars from
InterNIC, the only company to offer this service was Network Solutions, but now there
are many. I do not recommend Network Solutions: they’re expensive and incompetent.
If, as I recommend, you set up your mail server to refuse mail from servers without
reverse mapping, you will not be able to communicate with them, since they do not have
reverse DNS on their mail servers, and they use unregistered names for them. Judge for
yourself what this says about their technical competence.
One registrar that many FreeBSD people use is Gandi ( ), which is
slightly associated with the FreeBSD project. So far nobody has found anything negative
to say about them. Unlike Network Solutions, their web pages are also relatively simple
to understand.

Getting IP addresses
Once upon a time, it was possible to get IP addresses from InterNIC, but this practice is
now restricted to large allocations for ISPs. Instead, get the addresses from your ISP.
Routing considerations make it impractical to move IP addresses from one place to
another. If you move a long distance, you should expect to change your IP addresses in
the same way as you would change your telephone number.

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319                                                                        Chapter 18: Connecting to the Internet

Choosing an Internet Service Provider
In most cases, you will get your connection to the Internet from an Internet Service
Provider, or ISP. As the name suggests, an ISP will supply the means for you to connect
your system or your local network to the Internet. They will probably also supply other
services: most ISPs can’t live on Internet connections alone.
In this chapter we’ll look at the things you need to know about ISPs, and how to get the
best deal. We’ll concentrate on what is still the most common setup, PPP over a dialup
line with a V.90 modem (56 kbps), which will give you a peak data transfer rate of about
7 kB/s.

Who’s that ISP?
As the Internet, and in particular the number of dialup connections, explodes, a large
number of people have had the idea to become involved. In the early days of public
Internet access, many ISPs were small companies run by very technical people who have
seen a market opportunity and have grabbed it. Other ISPs were small companies run by
not-so technical people who have jumped on the bandwagon. Still other ISPs are run by
large companies, in particular the cable TV companies and the telephone companies.
Which is for you? How can you tell to which category an ISP belongs? Do you care?
You should care, of course. Let’s consider what you want from an ISP, and what the ISP
wants. You want a low-cost, high-reliability, high speed connection to the Internet. You
may also want technical advice and value-added services such as DNS (see Chapter 21)
and web pages.
The main priority of a small ISP (or any other ISP, for that matter) is to get a good night’s
sleep. Next, he wants to ensure the minimum number of nuisance customers. After that,
he wants to ensure that he doesn’t go out of business. Only then is he interested in the
same things that you are.
In the last few years, a large number of ISPs have gone out of business, and many more
have merged with other companies. In particular, large companies frequently bought out
small techie ISPs and then ran them into the ground with their incompetence. For a
humorous view of this phenomenon, see the ‘‘User Friendly’’ cartoon series starting at

Questions to ask an ISP
So how do you choose an ISP? Don’t forget the value of word-of-mouth—it’s the most
common way to find an ISP. If you know somebody very technical, preferably a
FreeBSD user, who is already connected, ask him—he’ll certainly be able to tell you
about his ISP. Otherwise, a lot depends on your level of technical understanding. It’s
easy to know more about the technical aspects of the Internet than your ISP, but it doesn’t
often help getting good service. Here are a few questions to ask any prospective ISP:,v v4.10 (2003/04/02 03:09:55)
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Who’s that ISP?                                                                                                 320

      What kind of connections do you provide?
               See the discussion on page 315.

      How do you charge? By volume, by connect time, or flat rate?
               Once most ISPs charged by connect time: you paid whether you transfer data or not. This
               made it unattractive to an ISP to provide good performance, since that would have meant
               that you could finish your session more quickly. Nowadays, flat rates are becoming more
               popular: you pay the same no matter how much you use the service. The disadvantage of
               the flat rate is that there is no incentive to disconnect, so you might find it difficult to
               establish connections.

               When comparing connect time and volume rates, expect an average data transfer rate of
               about 600 bytes per second for most connections via a 56 kbps modem. You’ll get up to 7
               kB per second with traffic-intensive operations like file downloading, but normally, you’ll be
               doing other things as well, and your data rate over the session is more likely to be 600 bytes
               per second if you’re reasonably active, and significantly less if not. Faster lines typically
               don’t charge by connect time: in particular, DSL lines are permanently connected and thus
               charge by data volume or at a flat rate.

               Another alternative that is again becoming more popular is a ‘‘download limit.’’ Your flat
               monthly fee allows you to download up to a certain amount of data, after which additional
               data costs money. This may seem worse than a flat rate, but it does tend to keep people from
               abusing the service.

      Do you have a cheaper charge for data from your own network?
               Many ISPs maintain web proxy caches, ftp archives and network news. If they charge by
               volume, some will give you free access to their own net. Don’t overestimate the value of
               this free data.

      What speed connections do you offer?
               ADSL connections have two different rates, a faster one for downloads and a slower one for
               the uplink. That’s fine if you’re planning to use the system as a client. If you intend to run
               servers on your system, things can look very different.

               If you are using a modem connection, they should be the fastest, of course, which are
               currently 56 kbps.

      What uplink connections do you have?
               The purpose of this question is twofold: first, see if he understands the question. An uplink
               connection is the connection that the ISP has to the rest of the Internet. If it’s inadequate,
               your connection to the Internet will also be inadequate. To judge whether the link is fast
               enough, you also need to know how many people are connected at any one time. See the
               question about dialup modems below.

      How many hops are there to the backbone?
               Some ISPs are a long way from the Internet backbone. This can be a disadvantage, but it
               doesn’t have to be. If you’re connected to an ISP with T3 all the way to the backbone,
               you’re better off than somebody connected directly to the backbone by an ISDN Basic Rate
               connection. All other things being equal, though, the smaller the number of hops, the better.

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321                                                                        Chapter 18: Connecting to the Internet

      How many dialup modems do you have?
               This question has two points to make as well. On the one hand, the total bandwidth of these
               modems should not exceed the uplink bandwidth by too much—let’s say it shouldn’t be
               more than double the uplink bandwidth. On the other hand, you want to be able to get a free
               line when you dial in. Nothing is more frustrating than having to try dozens of times before
               you can get a connection. This phenomenon also causes people not to disconnect when
               they’re finished, especially if there is no hourly rate. This makes the problem even worse.
               Of course, the problem depends on the number of subscribers, so ask the next question too.

      How many subscribers do you have? What is the average time they connect per
               Apart from the obvious information, check whether they keep this kind of statistics. They’re
               important for growth.

      What’s your up-time record? Do you keep availability statistics? What are they?
               ISPs are always nervous to publish their statistics. They’re never as good as I would like.
               But if they publish them, you can assume that that fact alone makes them better than their

      What kind of hardware and software are you running?
               This question will sort out the good techie ISPs from the wannabes. The real answers aren’t
               quite as important as the way they explain it. Nevertheless, consider that you’ll be better off
               with an ISP who also runs FreeBSD or BSD/OS.1 Only small ISPs can afford to use UNIX
               machines (including FreeBSD) as routers; the larger ones will use dedicated routers.

               Next, in my personal opinion, come other UNIX systems (in decreasing order of preference,
               Solaris 2.X, Linux and IRIX), and finally, a long way behind, Windows NT. If you’re
               looking for technical support as well, you’ll be a lot better off with an ISP who uses
               FreeBSD or BSD/OS. You’ll also be something special to them: most ISPs hate trying to
               solve problems for typical Windows users.

      How many name servers do you run?
               The answer should be at least 2. You’ll probably be accessing them for your non-local name
               server information, because that will be faster than sending requests throughout the Internet.

      Can you supply primary or secondary DNS for me? How much does it cost?
               I strongly recommend using your own domain name for mail. That way, if your ISP folds,
               or you have some other reason for wanting to change, you don’t need to change your mail
               ID. To do this, you need to have the information available from a name server 24 hours per
               day. DNS can generate a lot of traffic, and unless you’re connected to the network 100% of
               the time, mail to you can get lost if a system can’t find your DNS information. Even if you
               are connected 100% of the time, it’s a good idea to have a backup DNS on the other side of
               the link. Remember, though, that it doesn’t have to be your ISP. Some ISPs supply free
               secondaries to anybody who asks for them, and you might have friends who will also do it
               for you.

               The ISP may also offer to perform the domain registration formalities for you—for a fee.

1. BSD/OS is a commercial operating system closely related to FreeBSD. If you have a few thousand dollars to
   spare, you may even find it better than FreeBSD. Check out for further details.,v v4.10 (2003/04/02 03:09:55)
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Who’s that ISP?                                                                                                   322

               You can just as easily do this yourself: see page 318 for more details. Check the fee,
               though: in some countries, the ISP may get a discount for the domain registration fees. If
               it’s big enough, registering via the ISP may possibly be cheaper than doing it yourself.

      Can you route a class C network for me? What does it cost?
               If you’re connecting a local area network to the Internet, routing information must be
               propagated to the Net. ISPs frequently consider this usage to be ‘‘commercial,’’ and may
               jack up the prices considerably as a result.

               Alternatives to a full class C network are a group of static addresses (say, 8 or 16) out of the
               ISP’s own assigned network addresses. There’s no particular problem with taking this route.
               If you change ISPs, you’ll have to change addresses, but as long as you have your own
               domain name, that shouldn’t be a problem.

               Another possibility might be to use IP aliasing. See page 393 for more details.

      Can you supply me with a static address? How much does it cost?
               It’s highly desirable to have static addresses. See page 346 for more details. Unfortunately,
               many ISPs use static IPs to distinguish links for commercial use from those for home use,
               and may charge significantly more for a static address.

      Do you give complete access to the Internet, or do you block some ports?
               This is a complicated question. Many ISPs block services like smtp (mail) or http (web
               servers). If they do, you can’t run a mail or web server on your own machines. In the case
               of mail, this is seldom a problem: they will provide you with their own mail server through
               which you must relay your mail. This also allows the ISP to limit spam, which might
               otherwise come from any system within the network.

               For http, the situation is different. Usually ISPs charge money for supplying access to their
               own web servers. On the other hand, this arrangement can provide much faster web access,
               especially if you are connected by a slow link, and you may also save volume charges.
               Ultimately it’s a choice you need to make.

      Do you have complete reverse DNS?
               In previous editions of this book, I didn’t ask this question: it seemed impossible that any
               ISP would answer ‘‘no.’’ Unfortunately, times have changed, and a number of ISPs not only
               don’t supply DNS, they seem to think it unnecessary. Don’t have anything to do with them:
               firstly, it shows complete incompetence, and secondly it will cause trouble for you accessing
               a number of sites, including sending mail to the FreeBSD mailing lists.

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323                                                                           Chapter 18: Connecting to the Internet

Making the connection
After calling a few ISPs, you should be able to make a decision based on their replies to
these questions. The next step is to gather the information needed to connect. Use Table
18-1 to collect the information you need. See Chapter 20 for information about
authentication, user name and password.

Table 18-1: Information for ISP setup

 Information                                                     Fill in specific value

 IP address of your end of the link

 IP address of the other end of the link

 Kind of authentication (CHAP, PAP,

 User or system name

 Password or key

 Primary Name Server name

 Primary Name Server IP address

 Secondary Name Server name

 Secondary Name Server IP address

 Pop (Mail) Server Name

 News Server Name,v v4.10 (2003/04/02 03:09:55)

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