Website down: A network issue?

What is Ping?

Ping is a network test. It works by sending a request to a server to verify if we have a reply and determine the response time. The purpose is to verify that there’s no communication problems with servers via internet.

TCP Ping & ICMP Ping

Both are network tests. The difference is the protocol used (the systems of communication tested will be different between the TCP ping and the ICMP ping).

ICMP ping measures the connectivity with the server via the internet network. Nevertheless, sometimes production machines do not respond to ICMP ping. This is not due to a technical issue, but it is a deliberate choice to close the communication system. To overcome the event in which the ICMP test is not conclusive, we run a second test with a protocol that is always reachable : TCP ping. This works on the same principle as ICMP, but via a TCP protocol, on Port 80, the communication medium of your web servers. Port 80 is always open, because closing it would make your site unavailable.


  • What do the red bars mean?

If you see a red bar on this chart (see video for instructions), it means your website is unavailable because of a network problem. The ping response time depends on the network quality and the number of hops between the QUANTA probes and your site's server. For the sake of clarity, we will separate what does not matter, what deserves your attention and which requires emergency response.

It should be noted that at present, all measurements are taken from our infrastructure in France. If your website is hosted in another country, it is possible that the latency is higher. We are actively working to deploy our infrastructure in other countries.

  • Urgent situation

A red bar on the both charts means that connection to your site is impossible because of a network problem. In that case, please report the information immediately to your hoster or network administrator.

  • High priority situations:

A substantial increase in response time or recurring peaks on the charts reflect a bandwidth problem or a change in the path between our internet probe and your site. It is recommended in this situation to escalate this information to your provider or network administrator.

  • Not worrying situations:

- An isolated peak on one of the two charts is not serious. In the time of just one test, it is likely that the site’s users may not have been disturbed.
- A continuous red bar since Quanta’s installation on the ICMP chart means that this communication has been deliberately closed, this does not constitute an anomaly, but for better visibility on the network quality, ask your network administrator (or host) to open access to ICMP ping.
- If a red bar suddenly appears on your ICMP chart, but the TCP test still works, do not panic, your site is still available. This means that the ICMP communication system was deliberately cut off.

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