What if primary dns is down

If one is down, the other one is tried. It'll be a bad idea to have one of the servers in Tokyo, if all of your customers are in New York, because it'll increase the latency of the average resolution e.

The DNS spec does appear to require that at least two NS records are provided for a domain, so, you might run into some resolvers failing to resolve a name if you somehow manage to set up only a single NS record for your domain. A good overview on the misconceptions of a secondary third-party DNS service is provided by DJB, the author of djbdns:.

The service companies' claims are wildly exaggerated, and should never be used as a substitute for common sense. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. Why should one have a secondary DNS server? Ask Question. Asked 10 years, 3 months ago. Active 5 years, 8 months ago. Viewed 70k times. I'm very confused. Hopefully someone can see what I'm hung up on, and provide some guidance.

Improve this question. HopelessN00b Sam Levin Sam Levin 1 1 gold badge 4 4 silver badges 11 11 bronze badges. Possibly relevant: serverfault. Add a comment. Active Oldest Votes. I hope this helps your understanding. Improve this answer. Is the point of having secondary DNS Only extremely small organizations can do everything on a single server. Zoredache Zoredache k 37 37 gold badges silver badges bronze badges.

However, when your server is down there are a number of reasons you may want a backup DNS server, including: to enable you to ping or traceroute to your host to verify it is down. BillThor BillThor Now, you block access to 1.

DNS request timed out. And if your secondary dns server is accessible and working, you will get answer from secondary dns server. The secondary should be able to get updates for any changes on data in the primary. The primary must be setup to provide the data for syncing if requested by the secondary.

You can specify which DNS server to use for each check. Check both servers regularly especially after you make changes to the Primary to make sure the Secondary properly obtained synced the new data and thus giving out the same answers to any DNS query that it may receive. With nslookup, you can also do a reverse lookup… IP address to domain name besides the standard domain name to IP address. You may want to create a script that does nothing but do automated nslookup regularly, and if the query obtains a wrong response or times out, you get an email alarm of errors or failures.

That will tell you of problems before both primary and secondary DNS servers die. Setting up DNS servers is one thing, checking them and checking them regularly is another. You should be doing them all for proper management of your network and servers. You can even create third, fourth, ad infinitum… number of DNS servers as backup. Many big networks have multiple DNS to keep their networks humming. You can be sure they check them regularly as well.

Here is a dns checker you can use on-line. In terms of data , the primary DNS server gets information directly from local files. When it comes to secondary DNS servers, they only hold read-only copies of the zone file, which gets information directly from the primary server. However, it can have multiple secondary DNS servers for the same zone. It happens. You leave your router to do its work, somewhere up on a shelf or behind the TV, and dust settles upon it.

Soon you notice that sometimes your Internet connection is intermittent or slow Despite changes in technology, a hardwired network is still the faster, safer, and more reliable option over wireless. So which cable category do you choose for hardwiring your home Skip to content. Clients will get a port-unreachable ICMP response.

Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. Asked 5 years, 3 months ago. Active 4 years, 11 months ago. Viewed 1k times. Any idea what's happening or is this normal?

JR EDiT: Even when I change the scope and set the workstations to look at the secondary DNS first, still have the same slowness, just nslookup responds quickly and correctly.