Apply DNS Failover and Monitoring Settings

DNS Failover / Monitoring is DNS Made Easy's simple way to keep your systems up most of the time and also be the first to know if your sytems are having any problems. Our powerful monitoring sytems will check your sytems from multiple locations on our multi-homed bandwidth. If we notice your machines are offline we will notify you and also change your IPs to a working system if you desire.

You can read up more abount DNS Failover and System Monitoring by reading these links:

• DNS Failover Product Page
• System Monitoring Product Page

Since DNS Failover and System Monitoring check the IPs of your computers it makes most sense if they are tied to your A records (since A record assign IPs to your domains). So that is where the configuration is done. Here are the simple steps that you will need to apply DNS Failover / Monitoring to your domains:

1. Click on the appropriate "Records" next to the Record Set Template or Domain Name.

   

2. If your account has the ability to Failover / Monitor your A records will have a column named "FO / SM". This stands for Failover / System Monitoring. Click on on the appropriate A record that you want to apply Failover / System Monitoring for.

   

3. Follow the instructions on the screen to configure your failover and monitoring for your A record. There are detailed instructions on the screen and there is also help (click on the questions marks).

Here are some tips, tricks, and questions that will help you using the DNS Failover services.

• How can I share multiple domains with only one DNS Failover / System Monitor so I do not have to purchase multiple systems.
  • You will want to set your DNS Failover in a Record Set Template. We have a full tutorial on this.
    
• Do NOT set your TTLs to extremely low values thinking that you will get a faster change. Many ISPs will ignore TTLs that are lower than 3 minutes (180 seconds) and they will default the TTL to much higher values. We recommend all users to set your TTL to values anywhere from 180 to 600 (3 to 10 minute cache).
  • The TTL is the amount of time that your record will cache in remote systems / name servers. So the longer the TTL the less frequest remote systems will lookup your DNS record.
    • Records that do not use Failover and are static should set their TTLs anywhere from 1800 to 86400. You can always lower the TTL before you make a record change and then raise it back up again.
• How fast will users move over to the new IP?
  • This depends on when the user last queried a DNS Made Easy name server and how much longer the existing record is in cache. The DNS Made Easy name servers are updated / propagated immediately. So if your record has a 5 minutes cache (300 seconds) and if your user queried the name server 3 minutes before the primary server was detected that it was down then the user would still have the old IP for 2 more minutes.
  • The DNS Made Easy monitoring systems will check your system every 2 to 4 minutes. All updates are immediate.
    
• What about clients that use proxies?
  • If the proxy is configured / working properly you can set your screens so thay they will request your pages every time (information in your HTTP headers). However if the proxy server does not follow any HTTP headers and it also ignores the TTL of the DNS records then there really isn't anything that you can do. If the proxy server does not update the content no matter happens then that system has problems of it's own. A proxy server is suppose to "proxy" data, and not keep outdated data.