# Why not ZIP the damn thing


See [this code in github](https://github.com/miekg/dns/tree/zip), 
where I've implemented zipping DNS messages.
A modified `q` prints the compression rate at the first line. It only shows
how much compression you would get when you compress the *answer*.

For compression we use DEFLATE as described in RFC 1951. A typical example:

    q @open.nlnetlabs.nl MX miek.nl
    ;; Uncompressed/Compressed 253/142 (1.781690)
    ;; bla bla bla bla

That's not bad a compression factor of almost 1.8! Some more examples:

    # NOERROR
    q -dnssec @open.nlnetlabs.nl MX miek.nl
    ;; Uncompressed/Compressed 612/454 (1.348018)

    q -dnssec @ns1.sidn.nl SOA sidn.nl
    ;; Uncompressed/Compressed 1364/1025 (1.330732)

    # NSEC3 NXDOMAIN
    q -dnssec @ns1.nic.nl NS miek2.nl
    ;; Uncompressed/Compressed 1137/922 (1.233189)

    # Secure delegation
    q -dnssec @ns1.nic.nl NS miek.nl
    ;; Uncompressed/Compressed 482/339 (1.421829)
    
    # Root server list
    q -dnssec @a.root-servers.net NS .
    ;; Uncompressed/Compressed 1445/459 (3.148148)

So, from this (very) short test you see that you may be able to 
get an average compression of 33% (factor: 1.5). That's not *that*
bad... And the beauty is:

> There are some bits left in the OPCODE flag.