Other Server Software

Here you will find many ways to share your machine with the rest of the world or your local network. Before installing any packages in this chapter, you need to be sure you understand what the package does and how to set it up correctly. It might also be helpful to learn about the consequences of an improper setup so that you can analyze the risks.

BIND-9.3.0p1

Introduction to BIND

The BIND package provides a DNS server and client utilities. If you are only interested in the utilities, refer to the BIND Utilities-9.3.0p1.

Package information

BIND dependencies

Optional

OpenSSL-0.9.7e

Optional (to run the full test suite)

Net-tools-1.60 (for ifconfig) and Perl modules: Net-DNS

Optional (to [re]build documentation)

OpenJade-1.3.2, JadeTeX-3.13, DocBook DSSSL Stylesheets-1.78

Installation of BIND

Install BIND by running the following commands:

patch -Np1 -i ../9.3.0-patch1 &&
sed -i -e "s/dsssl-stylesheets/&-1.78/g" configure &&
./configure --prefix=/usr --sysconfdir=/etc \
    --enable-threads --with-libtool &&
make

Now, as the root user:

make install &&
chmod 755 \
    /usr/lib/{lib{bind9,isc{,cc,cfg},lwres}.so.?.?.?,libdns.so.20.0.0} &&
mv /usr/share/man/man8/named.conf.5 /usr/share/man/man5 &&
cd doc &&
install -d -m755 /usr/share/doc/bind-9.3.0/{arm,draft,misc,rfc} &&
install -m644 arm/*.html \
    /usr/share/doc/bind-9.3.0/arm &&
install -m644 draft/*.txt \
    /usr/share/doc/bind-9.3.0/draft &&
install -m644 rfc/* \
    /usr/share/doc/bind-9.3.0/rfc &&
install -m644 \
    misc/{dnssec,ipv6,migrat*,options,rfc-compliance,roadmap,sdb} \
    /usr/share/doc/bind-9.3.0/misc

In order to run the complete test suite before installing the package, you need to set up some dummy interfaces (requires ifconfig). Issue the following commands to run the complete suite of tests (you will have to be the root user to issue the ifconfig commands):

bin/tests/system/ifconfig.sh up &&
make check >check.log 2>&1 &&
bin/tests/system/ifconfig.sh down

If desired, issue the following command to ensure all 145 tests ran successfully:

grep "R:PASS" check.log | wc -l

Command explanations

patch -Np1 -i ../9.3.0-patch1: There's a vulnerability in the DNSSEC code. See http://www.kb.cert.org/vuls/id/938617. The patch fixes the bug.

sed -i -e ... configure: This command forces configure to look for the DSSSL stylesheets in the standard BLFS location.

--sysconfdir=/etc: This parameter forces BIND to look for configuration files in /etc instead of /usr/etc.

--enable-threads: This parameter enables multi-threading capability.

--with-libtool: This parameter forces the building of dynamic libraries and links the installed binaries to these libraries.

cd doc; install ...: These commands install the additional package documentation. Optionally, omit any or all of these commands.

Configuring BIND

Config files

named.conf, root.hints, 127.0.0, rndc.conf and resolv.conf

Configuration Information

BIND will be configured to run in a chroot jail as an unprivileged user (named). This configuration is more secure in that a DNS compromise can only affect a few files in the named user's HOME directory.

Create the unprivileged user and group named:

groupadd named &&
useradd -m -c "BIND Owner" -g named -s /bin/false named

Set up some files, directories and devices needed by BIND:

cd /home/named &&
mkdir -p dev etc/namedb/slave var/run &&
mknod /home/named/dev/null c 1 3 &&
mknod /home/named/dev/random c 1 8 &&
chmod 666 /home/named/dev/{null,random} &&
mkdir /home/named/etc/namedb/pz &&
cp /etc/localtime /home/named/etc

Then, generate a key for use in the named.conf and rdnc.conf files using the rndc-confgen command:

rndc-confgen -b 512 | grep -m 1 "secret" | cut -d '"' -f 2

Create the named.conf file from which named will read the location of zone files, root name servers and secure DNS keys:

cat > /home/named/etc/named.conf << "EOF"
 options {
     directory "/etc/namedb";
    pid-file "/var/run/named.pid";
    statistics-file "/var/run/named.stats";
       
 };
 controls {
     inet 127.0.0.1 allow { localhost; } keys { rndc_key; };
 };
 key "rndc_key" {
     algorithm hmac-md5;
     secret "[Insert secret from rndc-confgen's output here]";
 };
 zone "." {
     type hint;
     file "root.hints";
 };
 zone "0.0.127.in-addr.arpa" {
     type master;
     file "pz/127.0.0";
 };

// Bind 9 now logs by default through syslog (except debug).
// These are the default logging rules.

logging {
     category default { default_syslog; default_debug; };
     category unmatched { null; };

  channel default_syslog {
      syslog daemon;                      // send to syslog's daemon
                                          // facility
      severity info;                      // only send priority info
                                          // and higher
  };

  channel default_debug {
      file "named.run";                   // write to named.run in
                                          // the working directory
                                          // Note: stderr is used instead
                                          // of "named.run"
                                          // if the server is started
                                          // with the '-f' option.
      severity dynamic;                   // log at the server's
                                          // current debug level
  };

  channel default_stderr {
      stderr;                             // writes to stderr
      severity info;                      // only send priority info
                                          // and higher
  };

  channel null {
     null;                                // toss anything sent to
                                          // this channel
  };
};



EOF

Create the rndc.conf file with the following commands:

cat > /etc/rndc.conf << "EOF"
key rndc_key {
algorithm "hmac-md5";
    secret
    "[Insert secret from rndc-confgen's output here]";
    };
options {
    default-server localhost;
    default-key    rndc_key;
};
EOF

The rndc.conf file contains information for controlling named operations with the rndc utility.

Create a zone file with the following contents:

cat > /home/named/etc/namedb/pz/127.0.0 << "EOF"
$TTL 3D
@      IN      SOA     ns.local.domain. hostmaster.local.domain. (
                        1       ; Serial
                        8H      ; Refresh
                        2H      ; Retry
                        4W      ; Expire
                        1D)     ; Minimum TTL
                NS      ns.local.domain.
1               PTR     localhost.
EOF

Create the root.hints file with the following commands:

[Note]

Note

Caution must be used to ensure there are no leading spaces in this file.

cat > /home/named/etc/namedb/root.hints << "EOF"
.                       6D  IN      NS      A.ROOT-SERVERS.NET.
.                       6D  IN      NS      B.ROOT-SERVERS.NET.
.                       6D  IN      NS      C.ROOT-SERVERS.NET.
.                       6D  IN      NS      D.ROOT-SERVERS.NET.
.                       6D  IN      NS      E.ROOT-SERVERS.NET.
.                       6D  IN      NS      F.ROOT-SERVERS.NET.
.                       6D  IN      NS      G.ROOT-SERVERS.NET.
.                       6D  IN      NS      H.ROOT-SERVERS.NET.
.                       6D  IN      NS      I.ROOT-SERVERS.NET.
.                       6D  IN      NS      J.ROOT-SERVERS.NET.
.                       6D  IN      NS      K.ROOT-SERVERS.NET.
.                       6D  IN      NS      L.ROOT-SERVERS.NET.
.                       6D  IN      NS      M.ROOT-SERVERS.NET.
A.ROOT-SERVERS.NET.     6D  IN      A       198.41.0.4
B.ROOT-SERVERS.NET.     6D  IN      A       192.228.79.201
C.ROOT-SERVERS.NET.     6D  IN      A       192.33.4.12
D.ROOT-SERVERS.NET.     6D  IN      A       128.8.10.90
E.ROOT-SERVERS.NET.     6D  IN      A       192.203.230.10
F.ROOT-SERVERS.NET.     6D  IN      A       192.5.5.241
G.ROOT-SERVERS.NET.     6D  IN      A       192.112.36.4
H.ROOT-SERVERS.NET.     6D  IN      A       128.63.2.53
I.ROOT-SERVERS.NET.     6D  IN      A       192.36.148.17
J.ROOT-SERVERS.NET.     6D  IN      A       192.58.128.30
K.ROOT-SERVERS.NET.     6D  IN      A       193.0.14.129
L.ROOT-SERVERS.NET.     6D  IN      A       198.32.64.12
M.ROOT-SERVERS.NET.     6D  IN      A       202.12.27.33
EOF

The root.hints file is a list of root name servers. This file must be updated periodically with the dig utility. A current copy of root.hints can be obtained from ftp://rs.internic.net/domain/named.root. Consult the BIND 9 Administrator Reference Manual for details.

Create or modify resolv.conf to use the new name server with the following commands:

[Note]

Note

Replace [yourdomain.com] with your own valid domain name.

cp /etc/resolv.conf /etc/resolv.conf.bak &&
cat > /etc/resolv.conf << "EOF"
search [yourdomain.com]
nameserver 127.0.0.1
EOF

Set permissions on the chroot jail with the following command:

chown -R named.named /home/named

To start the DNS server at boot, install the /etc/rc.d/init.d/bind init script included in the blfs-bootscripts-6.0 package.

make install-bind

Now start BIND with the new boot script:

/etc/rc.d/init.d/bind start

Testing BIND

Test out the new BIND 9 installation. First query the local host address with dig:

dig -x 127.0.0.1

Now try an external name lookup, taking note of the speed difference in repeated lookups due to the caching. Run the dig command twice on the same address:

dig www.linuxfromscratch.org &&
dig www.linuxfromscratch.org

You can see almost instantaneous results with the named caching lookups. Consult the BIND Administrator Reference Manual located at doc/arm/Bv9ARM.html in the package source tree, for further configuration options.

Contents

Installed Programs: dig, dnssec-keygen, dnssec-signzone, host, isc-config.sh, lwresd, named, named-checkconf, named-checkzone, nslookup, nsupdate, rndc and rndc-confgen
Installed Libraries: libbind9.[so,a], libdns.[so,a], libisc.[so,a], libisccc.[so,a], libisccfg.[so,a] and liblwres.[so,a]
Installed Directories: /home/named, /usr/include/bind9, /usr/include/dns, /usr/include/dst, /usr/include/isc, /usr/include/isccc, /usr/include/isccfg, /usr/include/lwres and /usr/share/doc/bind-9.3.0

Short Descriptions

dig

interrogates DNS servers.

dnssec-keygen

is a key generator for secure DNS.

dnssec-signzone

generates signed versions of zone files.

host

is a utility for DNS lookups.

lwresd

is a caching-only name server for local process use.

named

is the name server daemon.

named-checkconf

checks the syntax of named.conf files.

named-checkzone

checks zone file validity.

nslookup

is a program used to query Internet domain nameservers.

nsupdate

is used to submit DNS update requests.

rndc

controls the operation of BIND.

rndc-confgen

generates rndc.conf files.