Sometimes MxToolbox may report your server as “Down” when you can reach it via browser or other connection. How is this possible?
First, MxToolbox makes at least two attempts to contact your server before listing you as “Down”. We make an initial contact on a preset periodic basis, governed by the monitor type. If the connection is successful, your site is listed as “Up”. If the connection times out, we attempt to make a second connection to verify that you are indeed down. This second connection attempt is made from a different geographical location. If the second connection times out, then you will be marked “Down” and reported as such using your Notification settings. We will continue to attempt connections to a “Down” system on the preset interval for up to 30 days, after which the system will be marked as permanently down. In the case that during the second connection attempt we are able to connect to your servers, we will ignore the initial check and report that your server is still in the “Up” state.
You are reported “Down” only when we have verified we cannot connect to you twice. This is similar to what a customer would experience.
Second, you may have access to your servers because you are on a local network, have cached DNS, or are simply physically closer to your servers than we are. When our connections time out, it could be due to a number of issues:
- Network Connection Lag – If the server is slow to respond or the network takes too many hops, our process may time out.
- DNS Misconfiguration – If we can’t find it, we can’t connect to it.
- Firewalls – A firewall may block our access to your server but allow you to access, either via VPN or ACL.
- Server Load – Sometimes your servers may be overloaded, causing low response times and our connections to time out.
- Wrong Port – Our monitors can be configured to check specific services on specific ports. Failure to connect might be because you are running a traditional service on a different port from the monitor. Check monitor settings to verify.
Our transcript results always provide some indication of why the system was reported as “Down” to help you troubleshoot the issue.
On every monitor, we have a “Check Now” button that will immediately start to recheck the server. If you can connect and we report you “Down” then try this. If it comes back up, it may be due to one of the conditions above having been remedied. This will also restart services to a monitor that has been down for more than 30 days.
For more information on our monitoring services, check out our handy comparison chart here.