[366e29e1] | 1 | <sect2>
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| 2 | <title>Configuring BIND</title>
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| 3 | <para>We will configure BIND to run in a chroot jail as an unprivileged
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| 4 | user(named). This configuration is more secure in that a DNS
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| 5 | compromise can only affect a few files in the named user's $HOME
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| 6 | directory </para>
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| 7 |
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| 8 | <para>First we set up some files and directories needed by
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| 9 | BIND:</para>
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| 10 | <para><screen><userinput>
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| 11 | groupadd -g 200 named &&
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| 12 | useradd -m -g named -u 200 -s /bin/false named &&
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| 13 | cd /home/named &&
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| 14 | mkdir -p dev etc/namedb/slave var/run &&
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| 15 | mknod /home/named/dev/null c 1 3 &&
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| 16 | mknod /home/named/dev/random c 1 8 &&
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| 17 | chmod 666 /home/named/dev/{null,random} &&
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| 18 | mkdir /home/named/etc/namedb/pz &&
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| 19 | cp /etc/localtime /home/named/etc
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| 20 | </userinput></screen></para>
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| 21 |
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| 22 | <sect3><title>Config files</title>
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| 23 | <para><userinput>named.conf, root.hints, 127.0.0, rndc.conf
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| 24 | </userinput></para>
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| 25 |
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| 26 | <para>Create the named.conf file with the following commands:</para>
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| 27 | <para><screen><userinput>
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| 28 | cat > /home/named/etc/named.conf << "EOF"
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| 29 | options {
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| 30 | directory "/etc/namedb";
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| 31 | pid-file "/var/run/named.pid";
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| 32 | statistics-file "/var/run/named.stats";
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| 33 |
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| 34 | };
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| 35 | controls {
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| 36 | inet 127.0.0.1 allow { localhost; } keys { rndc_key; };
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| 37 | };
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| 38 | key "rndc_key" {
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| 39 | algorithm hmac-md5;
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| 40 | secret "c3Ryb25nIGVub3VnaCBmb3IgYSBtYW4gYnV0IG1hZGUgZm9yIGEgd29tYW4K";
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| 41 | };
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| 42 | zone "." {
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| 43 | type hint;
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| 44 | file "root.hints";
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| 45 | };
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| 46 | zone "0.0.127.in-addr.arpa" {
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| 47 | type master;
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| 48 | file "pz/127.0.0";
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| 49 | };
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| 50 | EOF
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| 51 | </userinput></screen></para>
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| 52 | <para>Create a zone file with the following contents: </para>
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| 53 | <para><screen><userinput>
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| 54 | cat > /home/named/etc/namedb/pz/127.0.0 << "EOF"
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| 55 | $TTL 3D
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| 56 | @ IN SOA ns.local.domain. hostmaster.local.domain. (
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| 57 | 1 ; Serial
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| 58 | 8H ; Refresh
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| 59 | 2H ; Retry
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| 60 | 4W ; Expire
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| 61 | 1D) ; Minimum TTL
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| 62 | NS ns.local.domain.
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| 63 | 1 PTR localhost.
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| 64 | EOF
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| 65 | </userinput></screen></para>
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| 66 |
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| 67 | <para>Create the root.hints file with the following commands: </para>
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| 68 | <note><para>Caution must be used to insure no leading spaces in this
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| 69 | file.</para></note>
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| 70 | <para><screen><userinput>
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| 71 | cat > /home/named/etc/namedb/root.hints << "EOF"
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| 72 | . 6D IN NS A.ROOT-SERVERS.NET.
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| 73 | . 6D IN NS B.ROOT-SERVERS.NET.
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| 74 | . 6D IN NS C.ROOT-SERVERS.NET.
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| 75 | . 6D IN NS D.ROOT-SERVERS.NET.
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| 76 | . 6D IN NS E.ROOT-SERVERS.NET.
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| 77 | . 6D IN NS F.ROOT-SERVERS.NET.
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| 78 | . 6D IN NS G.ROOT-SERVERS.NET.
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| 79 | . 6D IN NS H.ROOT-SERVERS.NET.
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| 80 | . 6D IN NS I.ROOT-SERVERS.NET.
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| 81 | . 6D IN NS J.ROOT-SERVERS.NET.
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| 82 | . 6D IN NS K.ROOT-SERVERS.NET.
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| 83 | . 6D IN NS L.ROOT-SERVERS.NET.
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| 84 | . 6D IN NS M.ROOT-SERVERS.NET.
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| 85 | A.ROOT-SERVERS.NET. 6D IN A 198.41.0.4
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| 86 | B.ROOT-SERVERS.NET. 6D IN A 128.9.0.107
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| 87 | C.ROOT-SERVERS.NET. 6D IN A 192.33.4.12
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| 88 | D.ROOT-SERVERS.NET. 6D IN A 128.8.10.90
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| 89 | E.ROOT-SERVERS.NET. 6D IN A 192.203.230.10
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| 90 | F.ROOT-SERVERS.NET. 6D IN A 192.5.5.241
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| 91 | G.ROOT-SERVERS.NET. 6D IN A 192.112.36.4
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| 92 | H.ROOT-SERVERS.NET. 6D IN A 128.63.2.53
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| 93 | I.ROOT-SERVERS.NET. 6D IN A 192.36.148.17
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| 94 | J.ROOT-SERVERS.NET. 6D IN A 198.41.0.10
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| 95 | K.ROOT-SERVERS.NET. 6D IN A 193.0.14.129
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| 96 | L.ROOT-SERVERS.NET. 6D IN A 198.32.64.12
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| 97 | M.ROOT-SERVERS.NET. 6D IN A 202.12.27.33
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| 98 | EOF
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| 99 | </userinput></screen></para>
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| 100 |
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| 101 | <para>Create the rndc.conf with the following commands:</para>
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| 102 | <para><screen><userinput>
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| 103 | cat > /etc/rndc.conf << "EOF"
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| 104 | key rndc_key {
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| 105 | algorithm "hmac-md5";
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| 106 | secret
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| 107 | "c3Ryb25nIGVub3VnaCBmb3IgYSBtYW4gYnV0IG1hZGUgZm9yIGEgd29tYW4K";
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| 108 | };
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| 109 | options {
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| 110 | default-server localhost;
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| 111 | default-key rndc_key;
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| 112 | };
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| 113 | EOF
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| 114 | </userinput></screen></para>
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| 115 |
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| 116 | <para>Create or modify resolv.conf to use the new nameserver with the
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| 117 | following commands: </para>
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| 118 | <note><para>Replace yourdomain.com with your own valid domain
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| 119 | name.</para></note>
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| 120 |
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| 121 | <para><screen><userinput>
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| 122 | cp /etc/resolv.conf /etc/resolv.conf.bak
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| 123 | cat > /etc/resolv.conf << "EOF"
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| 124 | search yourdomain.com
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| 125 | nameserver 127.0.0.1
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| 126 | EOF
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| 127 | </userinput></screen></para>
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| 128 |
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| 129 | <para>Set permissions on the chroot jail with the following
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| 130 | command:</para>
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| 131 | <para><screen><userinput>
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| 132 | chown -R named.named /home/named
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| 133 | </userinput></screen></para>
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| 134 |
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| 135 | <para>Create the BIND boot script:</para>
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| 136 | <para><screen><userinput>
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| 137 | cat > /etc/rc.d/init.d/bind << "EOF"
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| 138 | #!/bin/bash
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| 139 | # Begin $rc_base/init.d/bind
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| 140 | # Based on sysklogd script from LFS-3.1 and earlier.
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| 141 | # Rewritten by Gerard Beekmans - gerard@linuxfromscratch.org
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| 142 | source /etc/sysconfig/rc
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| 143 | source $rc_functions
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| 144 | case "$1" in
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| 145 | start)
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| 146 | echo "Starting named..."
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| 147 | loadproc /usr/sbin/named -u named -t /home/named -c \
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| 148 | /etc/named.conf
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| 149 | ;;
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| 150 | stop)
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| 151 | echo "Stopping named..."
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| 152 | killproc /usr/sbin/named
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| 153 | ;;
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| 154 | restart)
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| 155 | $0 stop
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| 156 | sleep 1
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| 157 | $0 start
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| 158 | ;;
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| 159 | reload)
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| 160 | echo "Reloading named..."
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| 161 | /usr/sbin/rndc -c /etc/rndc.conf reload
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| 162 | ;;
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| 163 |
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| 164 | status)
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| 165 | statusproc /usr/sbin/named
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| 166 | ;;
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| 167 | *)
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| 168 | echo "Usage: $0 {start|stop|restart|status}"
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| 169 | exit 1
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| 170 | ;;
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| 171 | esac
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| 172 | # End $rc_base/init.d/bind
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| 173 | EOF
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| 174 | </userinput></screen></para>
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| 175 |
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| 176 | <para>Add the run level symlinks:</para>
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| 177 | <para><screen><userinput>
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| 178 | chmod 754 /etc/rc.d/init.d/bind &&
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| 179 | ln -s /etc/rc.d/init.d/bind /etc/rc.d/rc0.d/K90bind &&
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| 180 | ln -s /etc/rc.d/init.d/bind /etc/rc.d/rc1.d/K90bind &&
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| 181 | ln -s /etc/rc.d/init.d/bind /etc/rc.d/rc2.d/K90bind &&
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| 182 | ln -s /etc/rc.d/init.d/bind /etc/rc.d/rc3.d/S600bind &&
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| 183 | ln -s /etc/rc.d/init.d/bind /etc/rc.d/rc4.d/S600bind &&
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| 184 | ln -s /etc/rc.d/init.d/bind /etc/rc.d/rc5.d/S600bind &&
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| 185 | ln -s /etc/rc.d/init.d/bind /etc/rc.d/rc6.d/K90bind
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| 186 | </userinput></screen></para>
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| 187 |
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| 188 | <para>Now start BIND with the new boot script: </para>
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| 189 | <para><screen><userinput>
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| 190 | /etc/rc.d/init.d/bind start
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| 191 | </userinput></screen></para></sect3>
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| 192 |
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| 193 | <sect3><title>Testing BIND</title>
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| 194 | <para>Test out the new BIND 9 installation. First query the local
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| 195 | host address with dig:</para>
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| 196 | <para><screen><userinput>
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| 197 | dig -x 127.0.0.1
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| 198 | </userinput></screen></para>
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| 199 | <para>Now try an external name lookup, taking note of the speed
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| 200 | difference in repeated lookups due to the caching. Run the dig
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| 201 | command twice on the same address:</para>
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| 202 | <para><screen><userinput>
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| 203 | dig beyond.linuxfromscratch.org &&
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| 204 | dig beyond.linuxfromscratch.org
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| 205 | </userinput></screen>
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| 206 | You can see almost instantaneous results with the named caching
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| 207 | lookups. Consult bind-&bind-version;/doc/arm/Bv9ARM.html, the BIND
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| 208 | Administrator Reference Manual for further configuration options.
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| 209 | </para></sect3>
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| 210 | </sect2>
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| 211 |
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