Ping

About Ping

Ping tests whether a host is reachable and how quickly it accepts a connection, using four TCP connection attempts and reporting loss, minimum, average and maximum time in milliseconds. Because browsers and most web servers cannot send raw ICMP echo packets, this tool measures TCP handshake time instead, which is what a real user would experience.

How to use it

1. Enter a hostname or IPv4 address in the Hostname or IP box, such as example.com or 8.8.8.8.
2. Press Ping and give it a few seconds. It makes four sequential attempts, one after another.
3. Read the Summary card: the resolved IP, packets received out of four sent, percentage loss and the Min / Avg / Max round trip.
4. Open the Attempts table to see each sequence number with its time, marked with a check for success or a cross for failure.

Reading a partial-loss result

Host with one of four attempts timing out

Packets: 3/4 received (25% loss). The Attempts table shows sequence 3 as a cross and no time for that row.

When to use it

• Checking that a newly launched server answers before you announce it.
• Comparing handshake times to two hosting regions when choosing where to deploy.
• Telling a DNS problem apart from a network problem when a site will not open.
• Confirming a firewall rule change allowed web traffic through to a machine.

Questions about Ping

Is this a real ICMP ping?

No. Each attempt opens a TCP connection to port 80, and if that fails it tries 443, then 53, and records the time to connect. A host that blocks ICMP can still answer here, and one that closes all three ports will show 100 percent loss.

Why do I see loss for a host that is definitely online?

It only reaches ports 80, 443 and 53, each with a 3 second timeout. A machine that firewalls those three ports, or is only reachable on a custom port, looks dead to this test even though it is up.

Where is the ping sent from?

From our server, so the times describe the path between our data center and the target, not from your own connection. The hostname is sent to us for that reason, and the result is not a measure of your local latency.

Can I ping localhost or a private address?

No. Loopback, private and link-local addresses are refused before any connection is made. Only publicly routable hosts are accepted.

How often can I run it?

Five times per minute. One run can open up to twelve connections and keep a request busy for roughly half a minute when the host is unreachable, so it is the most tightly limited network tool here.

Related tools

• IP LookupLook up information about an IP address
• DNS LookupLook up DNS records for a domain
• WHOIS LookupLook up WHOIS information for a domain
• SSL LookupLook up SSL certificate information for a domain
• Reverse IP LookupFind domains hosted on an IP address
• ASN lookupFind the ASN, network operator, announced prefix, and country for an IP address or domain.