Figure 5
Welcome to the Four Calorie DNS Server for FreeBSD 6.0 (i386),
(fourcdns - beta test version)
This program was developed to be a companion to the "Four Calorie Web"
server application,
another of our programs that is available on the internet.
Older versions may be referred
to as the "Zero Calorie DNS" You may substitute the
term "four" for "zero" (and vice versa) in the documentation and license.txt files.
Please read the license file (License.txt)
This is the maiden voyage for this beta test version, so please be informed that the user accepts all risks involved with the usage of the software, or the inability to use the software. This version is very preliminary, and should not be used on the public internet (technically, it is capable of DNS service on an internet or an intranet).
Basic configuration
The server may be bound to any legal address and any legal port (valid ports are 1 thru 65535). The default port is 53, and the default address is 127.0.0.1, as specified in the configuration file (/usr/local/zerocaloriedns/zerocaloriedns.set) which can be found in the /usr/local/zerocaloriedns directory. The configuration file is named "zerocaloriedns.set" in both the "zero" calorie and "four" calorie distributions. The application directory is named "/usr/local/zerocaloriedns" in both distributions.
Note that the configuration file is a simple text file. (You may edit it with vi or gedit if you wish.)
The configuration file may contain four lines, as follows:
127.0.0.1
53
zerocalorieweb.com
127.0.0.1
Note that the domain name is the primary domain name, and does not include the
www "server" segment of the domain name. The "sub-domain" which is the third segment (immediately to the left of the
primary domain name) is often a mnemonic for the server type. The DNS server will be able
to resolve the "www" segment automatically, but it should not be added to the configuration
file. If the domain address is too short, it will be padded with zeroes.
(An entry of "2" would be translated to "2.0.0.0") Use complete four segment internet addresses.
The first entry (the address of the machine that the server is running on) will be used
as a binding hint, but the server may bind to other addresses that it is able to find
on the machine. Errors in the configuration file may cause the server to immediately exit it's
process when it is executed.
Changes made to the configuration file(s) are not effective until the server is stopped
and restarted. Re-executing the fourcdns file will not stop the server. Therefore,
the user should execute a kill command first. Assuming that there are no other unrelated
fourcdns processes running, the user could restart the server by executing:
killall fourcdns
./fourcdns
The Windows version of the DNS package sports a
nice utility for DNS Server management/monitoring. It is ZeroCDNSManager.exe, and is one of the
start menu items.
The FreeBSD 6.0 X Windows GUI for DNS server management is referred to by the file name fourcdnsmgr6:
fourcdnsmgr6
This server was developed to be a companion to the "Four-Calorie-Web" server program, which
is an HTTP web server. A web server without a DNS server is not very useful, unless
your visitors have a good memory for internet addresses!
This is the preliminary beta version of the DNS server, and should be used only for
purposes that are not important or that are tolerant of failure. (See license.txt)
There seems to be a dearth of DNS server applications for the Windows, Solaris, and FreeBSD platforms. Hopefully, this program will (when it eventually passes the hurdle of the beta-testing period) alleviate the DNS-application-scarcity problem. This particular server was designed to have only the functionality needed to power the companion "Four-Calorie-Web-Server" application.
The server resolves only the user's domain IP address, and no others. It cannot run as a general
purpose public DNS server in it's current configuration. This is an artificial
constraint, but it allows us to concentrate our efforts toward our specific goal (towards
powering the "Four-Calorie-Web" Server).
The server currently responds only to UDP requests, although TCP backup functionality
will be considered in the future. The server implements minimum functionality in other ways.
For instance, the header flags recursive bit is not set (recursion is not available). Some
things are "hardwired" this way to allow for maximum simplicity. A user should be able to
set-up the Four Calorie DNS server in a few minutes (If there are any other DNS servers that
can be set-up in two or three minutes, I am not aware of them).
The server auto-resolves all "server-type mnemonic" requests to the same
one-and-only IP address that is supplied by the user in the configuration file (So long as
the primary domain is correct).
In other words,
www.yourdomain.com and mail.yourdomain.com and ftp.yourdomain.com, and ns111.yourdomain.com all
resolve to the domain IP address .
This auto-resolution would not be desirable in a large server farm.
However, for an individual's toy web-site, it likely is a positive attribute. The server
does not resolve lower subdomains (those deeper than aaa.bbb.ccc).
Some client resolvers do not handle CNAME entries well, so after some
experimentation, it was decided to disallow CNAME functionality, and just return the primary
domain IP address for the next-level domain entries. A
maximum limit of 38 characters has been implemented for the entire domain.
The server currently handles standard foward (domain name) queries and reverse IP address queries,
MX, NS, and SOA queries, and little else. However, for a web server to function properly, the DNS server need not service
much more than standard forward and reverse queries.
The authoritative server flag is always set. The server does not currently support a zone transfer,
but version 1.2.0 now responds to SOA (Start of authority), NS (Nameserver), A (Address record),
MX and PTR (Reverse) requests, and knows to return an empty record for IPv6 requests that it will not
fulfill.
The serial number is auto-incremented, and changes only once per day, even when the
server is restarted. Since zone transfers are not allowed, this may or may not be an issue.
The NS, ARECORD and PTR requests served by **this** server will be accurate "up to the minute",
so long as the server was restarted after the configuration file change.
If one day serial updates are an issue, then don't use this server for your application.
The expiration is fixed (hard coded) to two weeks. For the serial updates to work correctly,
your machine must have a correct CMOS date (Your battery should be working).
The domain administrator's email has been hard coded to de@somedomain.com, where somedomain.com
is the content of the third line of the configuration file. The MX record has been hard coded to
mail.somedomain.com, where somedomain.com is defined in the third line of the configuration file.
Installation and Deinstallation Notes
Installation
The installation procedure has been changed to use the FreeBSD ports system. Instead
of extracting the tarball, simply copy the fourcdns-1.1.0.tar.gz file to the
/usr/ports/distfiles directory. Then, while the current directory is still
the directory that the outside tarball was extracted into (fourcdnsTempInstall)
type:
make install
Reboot. Upon restart, you should be able to type the name of the
GUI manager in an X windows terminal (fourcdnsmgr6) to start the GUI manager. You
should be able to start the DNS server manually by typing:
killall fourcdns
fourcdns
You should be able to see the manual pages by typing man fourcdns. Note that the
configuration file should still reside in the /usr/local/zerocaloriedns
directory.
The server will display a banner unless the -silent switch is used. The
banner will not indicate whether or not the server was able to bind to
the configured address. You must check the server status with sockstat, top, and
nslookup or dig:
i.e. dig @127.0.0.1 MX zerocalorieweb.com
Note that many internet web servers run in concert with a DNS server that handles only one domain.
The internet registry record points to a domain IP address for the owner's nameserver, and that nameserver may
in many cases be capable of returning only the IP-address for a single domain. (The owner's domain)
This DNS server is designed to do just that -- return the domain information for a single domain. This
model was chosen to create maximum simplicity, and a minimum of configuration headaches. The name server
has a fixed built-in name (ns111.yourdomain.com), where yourdomain.com is the domain that the
user entered into the third line of the configuration file. The last line of the configuration file is
the address of the domain and nameserver. (This is in contrast to the first line of the configuration
file, which is the address of the machine that the DNS server is running on). The addresses do not need to
reference the same machine.
If there are conflicts with the ns111 nameserver name, then you will have to
adjust the other conflicting name server to resolve the issue. If you have a big server farm, you probably
are not using this DNS server anyway. (And shouldn't be, as this version is the number one cut of the beta
test distribution!)
Easy DNS - HTTP setup ... all on one machine!
We stipulate that this beta version cannot be used on the public internet, however; the
following list describes what would be the relationship between the HTTP server and the
DNS server in any future public deployment of the HTTP and DNS servers:
Please read the license.txt file included with the installation media. This
version of the DNS server runs on FreeBSD 6.0 (i386)
No particular level of security is indicated or warranted for any portion of this software.
The output of the installation script that is generated via the FreeBSD ports
mechanism is shown in figure five.
Figure 5
Let us know what you think!
Note that this program is still in the development and testing phase, so
perfect function is not assured.
- don't use it for anything important!
Email suggestions to: rleesBSD@gmail.com, with subject line /Attn: RScheckelhoff /REF: Datazygte DNS