Here is our take on keeping name servers at the public domain registrar and the Network Solutions outage from earlier this week:
It had been common practice, especially for small-medium businesses, to keep name servers (where DNS information is maintained to point example.com to its IP addresses… as well as mail exchange, CNAMEs, etc) at the domain name registrar (the organization that reserves internet domain names for customers). The Network Solutions situation earlier this week made it clear to IT admins everywhere that the most vulnerable point in infrastructure may be at that name server level.
Name Servers offline means root domains (example.com), subdomains (cdn.example.com or www.example.com), MX records (to route email) and all records associated with a domain may be unavailable. A long TTL for a specific record may help mitigate outages for repeat name resolutions to a website or email being sent but eventually, when the TTL expires, those users will need to look to your name server for an updated record.
Until last summer, outages at a registrar (acting as a name server host) very rarely occurred. Since then:
- GoDaddy had an intermittent NS outage lasting roughly one business day
- Register.com NS were intermittently unavailable for 2 days
- July 2013, Network Solutions name servers were shaky for about 9 hours
There are a few options to handle public domain name resolution aside from keeping name servers at a registrar:
- Host name servers at a paid or dedicated DNS provider like AWS Route 53 or DNS Made Easy.
- Companies host their own public DNS servers. Set custom nameservers at the registrar.
- Redundant name servers – set multiple nameservers at the registrar. Zones files are periodically exported and synchronized between them.
We prefer to host name servers at Amazon Web Services Route 53. Cost is relatively nominal and AWS also provides DNS failover health checks (to automatically point to hot DR service locations). Although AWS Route 53 has not seen an outage yet but in the future it may be necessary to implement redundant name servers for more robust DNS infrastructure. We are currently evaluating the best process to implement public NS redundancy.
Amazon Web Services Route 53 Pricing:
$0.50 per hosted zone / month for the first 25 hosted zones
$0.10 per hosted zone / month for additional hosted zones
$0.500 per million queries – first 1 Billion queries / month
$0.250 per million queries – over 1 Billion queries / month
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This article was originally posted at Tritone Consultants by the same author.