How to manually update a DNS Zone serial for a single domain or for all domains

Introduction

You may want to have a command-line method of incrementing a DNS zone serial and reloading the DNS zone without using an editor.

Procedure

The following perl one liner will search for a string that start with 202 is all digits [0-9] with 7 more digits than 202 and increment that number and then replace the number with the incremented number. In 2030 the 202 would be replaced with 203 or modify the one liner to (20\d{8}) which covers the entire century.

The first example will increase a single DNS zone for example mydomain.com

perl -pi -e 'if (/\s+(202\d{7})/i) { my $i = $1+1; s/$1/$i/; }' /var/named/mydomain.com.db

This next example will increment the serial to all files in /var/named with a .db extension which results in all DNS zones being updated.

perl -pi -e 'if (/\s+(202\d{7})/i) { my $i = $1+1; s/$1/$i/; }' /var/named/*db

After the DNS Zone serial has been increased the DNS server needs to be reloaded.

Bind/named

rndc reload

PowerDNS

pdns_control reload

Lastly, if there is a DNS cluster being used you can force sync domains using

/scripts/dnscluster synczone mydomain.com

or all with

/scripts/dnscluster syncall