Free Secondary DNS Services

Redundancy is the key to reliability. You need two nameservers minimum, but more than seven is considered gluttonise. Pick two or three of these services to use. DNS uses UDP protocol which is 512 bytes/packet, if you list too many nameservers then they don't fit within 512 bytes. Eight seems to be a safe limit.

Most of these services do not use the notify funtionality. They poll the master server once an hour - or less often.

www.buddyns.com

  • unlimited domains for free (donation based)
  • secondary DNS only
  • focus on quick refresh (quick refresh intervals and [http://www.buddyns.com/tech/#pdq-updates real-time updates])
  • 4 servers - Texas, North Carolina, and two in Switzerland.
  • IPv6
  • DJ Bernstein TinyDNS 1.05
  • Recommended

www.everydns.net

  • Up to 20 domains for free, unlimited for $15 donation. This may no longer be the case since they were purchased by DynDNS. However, everyone who purchased previously is grandfathered in for free, such as myself.
  • Four geographically diverse (within the USA) servers.
  • Individual servers have some down time, but overall they are very reliable.
  • Recommended.
  • review

puck.nether.net/dns

  • One server in Chicago.
  • Slow to add data for new domains, but then works well.
  • Updates are done hourly.
  • IPv6 supported for Secondary DNS.

www.zoneedit.com

  • 5 domains free.
  • 2 nameservers for free, more if you pay (they have 19).
  • Once a domain is in their system it counts against your 5 maximum, forever, even if you delete it.
  • review

xname.org

  • Two servers on different networks, both in France.
  • Unlimited domains.
  • Slow to update, but pretty reliable.
  • I would use another service ahead of xname due to the system's slowness.

editdns.net

  • 5 servers, three in the USA (separate networks), and two in Europe.
  • Unlimited domains.
  • Uses default TTL minimum from SOA record for all records.
  • Webpage button to force manual axfr transfer for quick updates.
  • You would think that with three servers it would be reliable, but all three seem to be down at once on a recuring basis. They even lose DNS for their NS hostnames.

freedns.afraid.org/secondary

  • One server in Illinois.
  • Uses notify function for instant updating when you make changes.
  • ns2.afraid.org has not proven reliable.

pmsdns.org

  • The website claims two servers: ns1 and ns2.
  • ns3.pmsdns.org also has my dns records.
  • All are in Germany, 1 & 3 are on the same network.
  • ns1 and ns3 both pull axfr records from the master I told them too, but ns2 is pulling records from the server listed in the SOA record at the current DNS server. I was trying to setup new DNS servers and wanted the new data ready before I switched over, so I removed ns2 from my list of servers for the switchover.
  • ns1 has been reliable, ns2 has not.

www.twisted4life.com

  • 10 domains free
  • One server, ns1.twisted4life.com, in Malaysia or Singapore.
  • Does not accept TCP connections.
  • DNS configuration checker
  • Not the most reliable.

granitecanyon.com

  • Two servers.
  • Notoriously unreliable, if you can even get the website to work.
  • Minimum SOA values allowed:
    • 10800 ; Refresh (3 hours)
    • 3600 ; Retry (1 hour)
    • 43200 ; Time To Live (12 hours)

System NS

  • 3 DNS servers - Russia, France, and Ukraine.
  • Five domains for free.
  • Handles Secondary DNS, Dynamic DNS, or Primary DNS.
  • Website is very sparse.