Some notes regarding DNS for future reference, after watching DNS for developers - Maarten Balliauw session

• DNS is just a phone book to translate host names to ip addresses
• DNS holds different type of records. Using TXT record allows to store almost anything
• Never use public hotspot WIFI DNS servers
• Reduce the TTL before making changes to DNS records
• DNS query results are cached everywhere
• Simple DNS failover / load balancing
• AWS (Route53) and Azure allows to monitor the IP addresses and update the DNS records so you get better failover / load balancing

Very interesting for my projects the last section of the talk regarding service discovery.

Useful commands:

    dig A www.example.com +trace

    nslookup www.example.com 8.8.8.8

    # flush dns cache on OSX

    sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder