Slackware 13.37 - Dynamic DNS using Bind and ISC DHCP server
============================================================

Public domain
********************************************************************************
### Create a dnssec key


    # dnssec-keygen -a hmac-md5 -b 128 -n USER dhcpupdate
    Kdhcpupdate.+157+30215

    # ls
    Kdhcpupdate.+157+30215.key  Kdhcpupdate.+157+30215.private

    # cat Kdhcpupdate.+157+30215.key
    dhcpupdate. IN KEY 0 3 157 EFRHY4Vd4rOqbwphd5yGNA==

    # cat Kdhcpupdate.+157+30215.private
    Private-key-format: v1.2
    Algorithm: 157 (HMAC_MD5)
    Key: EFRHY4Vd4rOqbwphd5yGNA==
    Bits: AAA=

_if you run dnssec-keygen on virtual machines and it hangs for a while, add '-r /dev/urandom' option to dnssec-keygen command line._

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### /etc/named.conf

    
    options {
            directory "/var/named";
    };
    
    zone "." IN {
            type hint;
            file "caching-example/named.root";
    };
    
    zone "localhost" IN {
            type master;
            file "caching-example/localhost.zone";
            allow-update { none; };
    };
    
    zone "0.0.127.in-addr.arpa" IN {
            type master;
            file "caching-example/named.local";
            allow-update { none; };
    };
    
    key dhcpupdate {
            algorithm hmac-md5;
            secret "EFRHY4Vd4rOqbwphd5yGNA==";
    };

    zone "example.com" {
            type master;
            file "example.com.fwd";
            allow-update { key dhcpupdate; };
    };

    zone "1.16.172.in-addr.arpa" {
            type master;
            file "example.com.rev";
            allow-update { key dhcpupdate; };
    };

********************************************************************************
### /var/named/example.com.fwd

    $TTL 1D
    $ORIGIN example.com.
    @ SOA ns hostmaster (
            2012150700  ; sn
            1H          ; ref
            10M         ; ret
            1W          ; exp
            3H )        ; min
         NS ns
    ns   A  172.16.1.2

********************************************************************************
### /var/named/example.com.rev

    $TTL 1D
    $ORIGIN 1.16.172.in-addr.arpa.
    @ SOA ns.example.com. hostmaster.example.com. (
            2012071500  ; sn
            1H          ; ref
            10M         ; ret
            1W          ; exp
            3H )        ; min
         NS  ns1.example.com.
    2    PTR ns1.example.com.

********************************************************************************
### Restart bind

    chmod  +x /etc/rc.d/rc.bind
    /etc/rc.d/rc.bind restart

********************************************************************************
### Test with nsupdate 

    # nsupdate
    > server 172.16.1.2
    > key dhcpupdate EFRHY4Vd4rOqbwphd5yGNA==
    > zone example.com
    > update add laptop.example.com. 600 IN A 172.16.1.50
    > send
    > zone 1.16.172.in-addr.arpa
    > update add 50.1.16.172.in-addr.arpa 600 IN PTR laptop.example.com.
    > send
    > quit

    # dig +short @172.16.1.2 laptop.example.com
    172.16.1.50

    # dig +short @172.16.1.2 -x 172.16.1.50
    laptop.example.com.


    # nsupdate
    > server 172.16.1.2
    > key dhcpupdate EFRHY4Vd4rOqbwphd5yGNA==
    > zone example.com
    > update delete laptop.example.com.
    > send
    > zone 1.16.172.in-addr.arpa
    > update delete 50.1.16.172.in-addr.arpa 
    > send
    > quit

********************************************************************************
### Note

if your named server refused to start with the following warning logs:

    journal rollforward failed: journal out of sync with zone

delete .jnl files and restart bind:

    cd /var/named
    rm *.jnl
    /etc/rc.d/rc.bind restart

********************************************************************************
### /etc/dhcpd.conf

    ddns-update-style interim;
    update-static-leases on;
    
    default-lease-time 300;
    max-lease-time 3600;
    
    key dhcpupdate {
      algorithm hmac-md5;
      secret EFRHY4Vd4rOqbwphd5yGNA==;
    }
    
    zone example.com. {
            primary 172.16.1.2;
            key dhcpupdate;
    }
    
    zone 1.16.172.in-addr.arpa. {
            primary 172.16.1.2;
            key dhcpupdate;
    }
    
    subnet 172.16.1.0 netmask 255.255.255.0 {
            option routers 172.16.1.2;
            option subnet-mask 255.255.255.0;
            option domain-name-servers 37.152.160.18, 8.8.8.8;
            range 172.16.1.100 172.16.1.200;
            ddns-domainname "example.com";
            ddns-hostname = concat(binary-to-ascii(10, 8, "-", leased-address), ".dynamic");
            #ddns-hostname = binary-to-ascii (16, 8, "-", substring (hardware, 1, 6));
    
            host webserver {
                    hardware ethernet 3e:4b:37:00:82:00;
                    fixed-address 172.16.1.50;
                    ddns-hostname "www";
                    ddns-domainname "example.com";
            }
    }
    
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### Start dhcp server

    touch /var/state/dhcp/dhcpd.leases
    dhcpd

********************************************************************************
### Test dynamic lease

    # dig +short @172.16.1.2 172-16-1-100.dynamic.example.com
    172.16.1.100

    # dig +short @172.16.1.2 -x 172.16.1.100
    172-16-1-100.dynamic.example.com.

********************************************************************************
### Test static lease

    # dig +short @172.16.1.2  www.example.com
    172.16.1.50
    # dig +short @172.16.1.2  -x 172.16.1.50
    www.example.com.

********************************************************************************
### Dump journal files to zone files (freeze/unfreeze) - dynamic update temporarily disabled 

    rndc freeze example.com
    rndc freeze 1.16.172.in-addr.arpa
    rndc thaw example.com
    rndc thaw 1.16.172.in-addr.arpa

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### Important manuals
    
    man dhcpd.conf
    man dhcp-eval

********************************************************************************
_BY: Pejman Moghadam_  
_TAG: dhcpd, bind, ddns, dns_  
_DATE: 2012-07-15 14:04:49_