Ping a Specific Port

Question

Just a quick sanity check here.

Can you ping a specific port of a machine, and if so, can you provide an example?

I'm looking for something like ping ip address portNum.

Answer 1

You can't ping ports, as Ping is using ICMP which is an internet layer protocol that doesn't have ports. Ports belong to the transport layer protocols like TCP and UDP.

However, you could use nmap to see whether ports are open or not

nmap -p 80 example.com

Edit: As flokra mentioned, nmap is more than just a ping-for-ports-thingy. It's the security auditers and hackers best friend and comes with tons of cool options. Check the doc for all possible flags.

Answer 2

Open a telnet session to the specific port, for example:

# telnet google.com 80
Trying 74.125.226.48...
Connected to google.com.
Escape character is '^]'.

To close your session, hit Ctrl+].

Answer 3

If you're on a windows installation with powershell v4 or newer, you can use the test-netconnection powershell module:

Test-NetConnection <host> -port <port>

Example: Test-NetConnection example.com -port 80

This cmdlet also has the alias tnc. Eg tnc example.com -port 80

Answer 4

$ nc -vz google.com 80
Connection to google.com 80 port [tcp/http] succeeded!

Answer 5

You can use PaPing:

http://code.google.com/p/paping

C:\>paping.exe www.google.com -p 80 -c 4
paping v1.5.1 - Copyright (c) 2010 Mike Lovell

Connecting to www.l.google.com [209.85.225.147] on TCP 80:

Connected to 209.85.225.147: time=24.00ms protocol=TCP port=80
Connected to 209.85.225.147: time=25.00ms protocol=TCP port=80
Connected to 209.85.225.147: time=24.00ms protocol=TCP port=80
Connected to 209.85.225.147: time=24.00ms protocol=TCP port=80

Connection statistics:
        Attempted = 4, Connected = 4, Failed = 0 (0.00%)
Approximate connection times:
        Minimum = 24.00ms, Maximum = 25.00ms, Average = 24.25ms

Answer 6

Try curl command, like:

$ curl host:port

For example:

$ curl -s localhost:80 >/dev/null && echo Success. || echo Fail.
Success.

Above command will return Fail on a non-zero exit status codes. In some particular cases, such as empty or malformed response (see man curl), you may want to handle specific exit codes as successful, so please check this post for more detailed explanation.

Answer 7

No, you can't, because ping uses the ICMP protocol, which doesn't even have a concept of ports.

Answer 8

I found a simpler solution using PsPing:

psping 192.168.2.2:5000

It's part of Windows Sysinternals.

PsPing implements Ping functionality, TCP ping, latency and bandwidth measurement.

Answer 9

On Linux you can use hping but it uses TCP, rather than ICMP.

hping example.com -S -V -p 80

Answer 10

Ping is very specific but if you want to check whether a port is open or not, and are running a Windows box then PortQry is your friend.

I've only used it for testing Domain Controllers for connectivity issues, but it worked a treat for that, so should work for you.

Answer 11

Here's a quick and dirty .NET console app:

    static void Main(string[] args)
    {
        string addressArgument = null, portArgument = null;

        System.Net.Sockets.TcpClient tcpClient = null;

        try
        {
            addressArgument = args[0];
            portArgument = args[1];

            int portNumber;
            portNumber = Int32.Parse(portArgument);

            tcpClient = new System.Net.Sockets.TcpClient();
            tcpClient.ReceiveTimeout = tcpClient.SendTimeout = 2000;


            IPAddress address;
            if (IPAddress.TryParse(args[0], out address))
            {
                var endPoint = new System.Net.IPEndPoint(address, portNumber);
                tcpClient.Connect(endPoint);
            }
            else
            {
                tcpClient.Connect(addressArgument, portNumber);
            }

            Console.WriteLine("Port {0} is listening.", portArgument);
        }
        catch (Exception e)
        {
            if (e is SocketException || e is TimeoutException)
            {
                Console.WriteLine("Not listening on port {0}.", portArgument);
            }
            else
            {
                Console.WriteLine("Usage:");
                Console.WriteLine("    portquery [host|ip] [port]");
            }
        }
        finally
        {
            if (tcpClient != null)
                tcpClient.Close();
        }
    }

Answer 12

No.

There's no guarantee that the service running on the port understands ping. It also opens up the question of what "flavor" of port you want to ping, TCP or UDP? Since the ping "protocol" uses neither (ping is implemented using ICMP), it doesn't make a lot of sense.

Answer 13

This is the only solution that works for VPNs with the client machine being Windows Vista or Windows 7, as other listed answers simply do not function. This answer was previously deleted and should not have been, as this is the only solution for a real-world common case. Since there is no appeal available for the delete, I am reposting it to save others the frustration I had with trying to use the other answers.

The example below finds which IPs on the VPN that have VNC/port 5900 open with the client running on Windows 7.

A short Python (v2.6.6) script to scan a given list of IPs and Ports:

from socket import *

fTimeOutSec = 5.0
sNetworkAddress = '192.168.1'
aiHostAddresses = range(1,255)
aiPorts = [5900]

setdefaulttimeout(fTimeOutSec)
print "Starting Scan..."
for h in aiHostAddresses:
    for p in aiPorts:
        s = socket(AF_INET, SOCK_STREAM)
        address = ('%s.%d' % (sNetworkAddress, h))
        result = s.connect_ex((address,p))
        if ( 0 == result ):
            print "%s:%d - OPEN" % (address,p)
        elif ( 10035 == result ):
            #do nothing, was a timeout, probably host doesn't exist
            pass
        else:
            print "%s:%d - closed (%d)" % (address,p,result)

        s.close()
print "Scan Completed."

Results looked like:

Starting Scan...
192.168.1.1:5900 - closed (10061)
192.168.1.7:5900 - closed (10061)
192.168.1.170:5900 - OPEN
192.168.1.170:5900 - closed (10061)
Scan Completed.

The four variables at the top would need to be changed to be appropriate to whatever timeout, network, hosts, and ports that are needed. 5.0 seconds on my VPN seemed to be enough to work properly consistently, less didn't (always) give accurate results. On my local network, 0.5 was more than enough.

Answer 14

I'm quite sure that Nagios check_tcp probe does what you want. They can be found here and although designed to be used in a Nagios context, they're all standalone programs.

$ ./check_tcp -H host -p 22
TCP OK - 0.010 second response time on port 22|time=0.009946s;0.000000;0.000000;0.000000;10.000000

Answer 15

As per CMCDragonkai's comment, you can use nping, which is part of Nmap.

nping example.com --tcp-connect -p 80,443

Here's a link to the manpage.

Answer 16

In Bash shell, you can use TCP pseudo-device file, for example:

</dev/tcp/serverfault.com/80 && echo Port open || echo Port closed

Here is the version implementing a timeout of 1 second:

timeout 1 bash -c "</dev/tcp/serverfault.com/81" && echo Port open || echo Port closed

Answer 17

There is a lightweigth tool for it, called tcping: http://www.linuxco.de/tcping/tcping.html

Answer 18

If you are running a *nix operating system try installing and using "zenmap", it is a GUI for nmap and has several useful scan profiles which are a great help to the new user.