Hi, I’m Marc Barry

A freelance C# developer and infrastructure specialist with an MSC in computer security working between London and Cardiff.


  • DNS toolbox

    A visual DNS toolbox supporting common query types such as A, NS, CNAME, SOA, PTR, MX, TXT, RP, AXFR, AAAA, ANY and IPv6.

  • Password generator

    A convenient way to quickly generate sets of complex passwords. Each page load generates a pseudo-random set of passwords with varying length and character compositions.


  • Protocol header cheetsheets

    A set of cheetsheets and diagrams for better understanding protocol headers and the sizes of Ethernet frames, IP packets, UDP datagrams, TCP packets and ICMP messages.