| 1 | DNS Exercise - Delegation |
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| 2 | ------------------------- |
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| 3 | |
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| 4 | In this exercise, we will create a new TLD in our root. |
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| 5 | for example: MYTLD |
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| 6 | |
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| 7 | You will create a master nameservice on your own machine, and someone else |
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| 8 | will provide slave service. Then you will ask the administrator for the |
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| 9 | domain above you (dns) to delegate your domain to you. |
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| 10 | |
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| 11 | Note: the following should be done as the "root" superuser. |
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| 12 | |
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| 13 | Firstly, note that your hostname is configured correctly |
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| 14 | on your machine. Check that it is configured correctly by |
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| 15 | using the 'hostname' command - e.g. on master.grpXX.ws.nsrc.org, if you type: |
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| 16 | |
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| 17 | # hostname |
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| 18 | |
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| 19 | You should see: |
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| 20 | |
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| 21 | master.grpXX.ws.nsrc.org |
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| 22 | |
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| 23 | If not, then configure your server with its name: e.g. for |
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| 24 | master.grp25.ws.nsrc.org, type: |
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| 25 | |
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| 26 | |
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| 27 | # hostname master.grp25.ws.nsrc.org |
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| 28 | |
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| 29 | Remember to replace "grpXX" with the the proper group number! |
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| 30 | |
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| 31 | Edit the file /etc/rc.conf (using "vi" or "ee", i.e.: ee /etc/rc.conf), |
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| 32 | and update the "hostname": |
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| 33 | |
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| 34 | hostname="master.grpXX.ws.nsrc.org" |
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| 35 | |
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| 36 | In the file /etc/hosts, you should see a line: |
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| 37 | |
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| 38 | 10.10.X.1 master.grpXX master.grpXX.ws.nsrc.org |
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| 39 | |
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| 40 | |
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| 41 | Exercise |
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| 42 | -------- |
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| 43 | |
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| 44 | * Choose a new domain, write it down somewhere |
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| 45 | |
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| 46 | i.e.: "MYTLD" or "EARTH" - whatever you feel like. |
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| 47 | |
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| 48 | (Do NOT choose any of the PC names, e.g. `master.grpXX`, as your subdomain) |
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| 49 | |
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| 50 | This could for example be the name of your country code, country name, |
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| 51 | company name, etc... but REMEMBER that someone might pick the same name! |
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| 52 | First come, first serve. |
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| 53 | |
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| 54 | * Find someone who will agree to be slave for your domain. Please find |
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| 55 | someone on a different table than you (Remember RFC2182: secondaries must |
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| 56 | be on remote networks but here we work on a flat net). You can |
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| 57 | have more than one slave if you wish. |
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| 58 | |
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| 59 | * Create your zone file in `/etc/namedb/master/MYTLD` |
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| 60 | (where MYTLD is your chosen domain) -- you can pretty much |
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| 61 | "copy and paste" the section below -- but remember to update |
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| 62 | the XXX with your IP: |
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| 63 | |
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| 64 | *** Remember, you will need to become root to create this file, |
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| 65 | *** so, e.g. |
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| 66 | *** |
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| 67 | *** $ cd /etc/namedb/master |
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| 68 | *** $ sudo vi MYTLD |
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| 69 | *** |
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| 70 | *** (feel free to use another editor instead of vi, e.g. joe, ee) |
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| 71 | |
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| 72 | - - - - - - - - - - - - - cut below - - - - - - - - - - - - |
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| 73 | |
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| 74 | $TTL 10m |
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| 75 | @ IN SOA master.grpXX.ws.nsrc.org. your@email.address. ( |
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| 76 | 2011021601 ; Serial |
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| 77 | 10m ; Refresh |
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| 78 | 5m ; Retry |
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| 79 | 4w ; Expire |
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| 80 | 10m ) ; Negative |
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| 81 | |
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| 82 | IN NS master.grpXXX.ws.nsrc.org. ; master |
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| 83 | IN NS master.grpYYY.ws.nsrc.org. ; slave |
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| 84 | |
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| 85 | www IN A 10.10.XXX.1 ; your own IP |
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| 86 | |
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| 87 | - - - - - - - - - - - - - cut above - - - - - - - - - - - - |
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| 88 | |
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| 89 | Replace `your@email.address.` with your home E-mail address. |
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| 90 | |
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| 91 | XXX and YYY are the IP of your group, and your slave's, respectively. |
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| 92 | |
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| 93 | We have chosen purposely low values for TTL, refresh, and retry to make |
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| 94 | it easier to fix problems in the classroom. For a production domain you |
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| 95 | might use higher values. |
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| 96 | |
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| 97 | * Edit `/etc/namedb/named.conf` and do the following: |
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| 98 | |
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| 99 | *** Remember, you will need to become root to edit this file, |
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| 100 | *** so, e.g. |
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| 101 | *** |
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| 102 | *** $ cd /etc/named |
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| 103 | *** $ sudo vi named.conf |
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| 104 | *** |
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| 105 | *** (feel free to use another editor instead of vi, e.g. joe, ee) |
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| 106 | |
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| 107 | - If it is still there, REMOVE the following line: |
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| 108 | |
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| 109 | listen-on { 127.0.0.1; }; |
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| 110 | |
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| 111 | ... and add another line in the options section: |
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| 112 | |
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| 113 | allow-query { any; }; |
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| 114 | |
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| 115 | ... so that your nameserver will now answer queries from the network |
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| 116 | |
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| 117 | - Add a section to configure your machine as master for |
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| 118 | your domain, by adding something like this at the end |
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| 119 | (the bottom) of the file: |
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| 120 | |
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| 121 | zone "MYTLD" { |
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| 122 | type master; |
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| 123 | file "/etc/namedb/master/MYTLD"; |
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| 124 | }; |
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| 125 | |
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| 126 | Pay attention to the ';' and '}' ! |
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| 127 | |
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| 128 | * Check that your config file and zone file are valid: |
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| 129 | |
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| 130 | # named-checkconf |
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| 131 | # named-checkzone MYTLD /etc/namedb/master/MYTLD |
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| 132 | |
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| 133 | * If there are any errors, correct them ! * |
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| 134 | |
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| 135 | * If this is not already done, enable named in your server's configuration, |
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| 136 | by editing the file /etc/rc.conf and adding, if this is not already done: |
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| 137 | |
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| 138 | ** Remember, again, you need to be root to edit this file |
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| 139 | |
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| 140 | named_chrootdir="" |
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| 141 | named_enable="YES" |
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| 142 | |
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| 143 | - Then start/restart named with |
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| 144 | |
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| 145 | # /etc/rc.d/named restart |
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| 146 | |
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| 147 | Check the result with |
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| 148 | |
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| 149 | # tail /var/log/messages |
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| 150 | |
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| 151 | Verify with dig that MYTLD is now configured on your host: |
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| 152 | |
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| 153 | # dig @localhost MYTLD. NS |
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| 154 | |
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| 155 | You can also check the nameserver status using rndc: |
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| 156 | |
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| 157 | # rndc status |
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| 158 | |
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| 159 | - If there are any errors, correct them. Some configuration errors can |
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| 160 | cause the daemon to die completely, in which case you may have to |
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| 161 | start it again: |
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| 162 | |
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| 163 | # /etc/rc.d/named restart |
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| 164 | |
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| 165 | * Assist your slaves to configure themselves as slave for your domain, and |
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| 166 | configure yourself as a slave if asked to do so by another table. |
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| 167 | |
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| 168 | The instructions for how to do this are not complicated, but here's a hint: |
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| 169 | |
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| 170 | zone "MYTLD" { |
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| 171 | type slave; |
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| 172 | masters { 10.10.XXX.1; }; |
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| 173 | file "/etc/namedb/slave/MYTLD"; |
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| 174 | }; |
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| 175 | |
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| 176 | ... where XXX is the IP of the group of your slave. |
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| 177 | |
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| 178 | Remember, you will also need to be a slave for someone else's zone! |
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| 179 | |
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| 180 | When you have changed your `named.conf` so that you are a slave for |
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| 181 | someone else, make sure there are no errors in `/var/log/messages` after |
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| 182 | you restart your nameserver. |
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| 183 | |
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| 184 | * Check that you and your slaves are giving authoritative answers for |
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| 185 | your domain: |
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| 186 | |
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| 187 | # dig +norec @10.10.XXX.1 MYTLD. SOA |
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| 188 | # dig +norec @10.10.YYY.1 MYTLD. SOA |
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| 189 | |
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| 190 | Check that you get an AA (authoritative answer) from both, and that |
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| 191 | the serial numbers match. |
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| 192 | |
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| 193 | * Now you are ready to request delegation – indicate to the instructor, |
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| 194 | on a piece of paper: |
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| 195 | |
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| 196 | |
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| 197 | Domain name: ___________________ |
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| 198 | |
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| 199 | Master nameserver: master.grp___.ws.nsrc.org |
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| 200 | |
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| 201 | Slave nameserver: master.grp___.ws.nsrc.org |
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| 202 | |
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| 203 | |
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| 204 | * You will not get delegation until the instructor has checked: |
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| 205 | |
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| 206 | - Your nameservers are all authoritative for your domain |
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| 207 | - They all have the same SOA serial number |
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| 208 | - The NS records within the zone match the list of servers you are |
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| 209 | requesting delegation for |
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| 210 | - The slave(s) are not on the same side of the room as you :) |
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| 211 | |
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| 212 | => This is called policy! |
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| 213 | |
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| 214 | * Once you have delegation, try to resolve www.MYTLD: |
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| 215 | |
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| 216 | - On your own machine |
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| 217 | - On someone else's machine (who is not slave for you): |
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| 218 | |
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| 219 | # dig @10.10.XXX.1 www.MYTLD (where MYTLD is your domain) |
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| 220 | |
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| 221 | * Add a new resource record to your zone file. Remember to update the |
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| 222 | serial number. Check that your slaves have updated. Try resolving this |
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| 223 | new name. |
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