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 doesn't have the concept of 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

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 4

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

Answer 5

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 6

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 7

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 8

This is the only solution that works for VPNs on 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 allowed 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 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. ` 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 9

i'm feeling lucky on google for “ping a specific port”: http://philwilks.blogspot.com/2008/01/ping-specific-port.html, so NO, you cannot ping a specific port

you can use nmap though: nmap -p <port> <host>

Answer 10

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.

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

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

Answer 13

Or instead of paping you could use cryping which has been around much longer and supports pinging of some services as well as ports.

Answer 14

Try port knocking software. Personally I use KnockKnock ( http://sourceforge.net/projects/knockknock/ ). It remembers the combination of ports and the IP.