Commands tagged port (15)

  • Using netcat (nc) 25 can be replaced with the friendly value (smtp). Check error code for result or use -v option to echo output nc -z localhost smtp && echo open || echo closed nc -zv host protocol Show Sample Output

    nc -zv localhost 25
    toaster · 2013-11-21 22:04:00 3

  • -2
    netstat -lntp
    fr00tyl00p · 2013-11-20 10:02:10 0

  • -2
    sudo lsof -iTCP:25
    netaxiz · 2013-11-20 08:26:37 2

  • 0
    sudo lsof -iTCP:25 -sTCP:LISTEN
    pdxdoughnut · 2013-11-12 17:32:34 0
  • netstat will list all open ports on the system, unix sockets, tcp sockets and udp sockets. the t flag limits to tcp ports the l flag limits to listening ports and the n flag disables the translation of port to service ( ie :25 displayed instead of :smtp ). then grep for the port you are interested in preceeded by a colon. Show Sample Output

    netstat -tln | grep :25
    Peteches · 2013-11-12 16:47:06 0
  • Check trough unix sockets if tcp port is open or close Show Sample Output

    (echo >/dev/tcp/localhost/25) &>/dev/null && echo "TCP port 25 open" || echo "TCP port 25 close"
    YouM · 2013-11-12 02:11:01 1

  • 0
    sudo port selfupdate && sudo port upgrade outdated && sudo port clean --all installed && sudo port -f uninstall inactive
    noah · 2013-06-26 01:12:33 0
  • Simple way to test if a port is available to the public. Run this command on the "server" and run a `telnet host-ip port-number` on the client. Test by sending strings to the server, which will be displayed in the server terminal.

    nc -l <port-number>
    cybertoast · 2013-03-20 15:25:57 1

  • 1
    lsof -nPi tcp:80
    arighi · 2012-01-09 09:35:17 0

  • 16
    fuser -v 80/tcp
    pykler · 2011-12-16 14:51:34 0
  • Check to see if a port is open or closed on a given host. Show Sample Output

    checkport() { sudo nmap -sS -p $1 $2 }
    peterRepeater · 2011-12-13 11:46:15 1
  • shows opened ports on machine in continuous mode (refreshing every 10 sec) Show Sample Output

    netstat -tulpnc
    altern · 2011-04-20 07:30:31 1
  • -z: Specifies that nc should just scan for listening daemons, without sending any data to them -u: Use UDP instead of the default option of TCP. Show Sample Output

    nc -z <IP> <TCP port> OR nc -zu <IP> <UDP port>
    frank514 · 2011-04-01 04:08:53 1
  • The command copies a file from remote SSH host on port 8322 with bandwidth limit 100KB/sec; --progress shows a progress bar --partial turns partial download on; thus, you can resume the process if something goes wrong --bwlimit limits bandwidth by specified KB/sec --ipv4 selects IPv4 as preferred I find it useful to create the following alias: alias myscp='rsync --progress --partial --rsh="ssh -p 8322" --bwlimit=100 --ipv4' in ~/.bash_aliases, ~/.bash_profile, ~/.bash_login or ~/.bashrc where appropriate. Show Sample Output

    rsync --progress --partial --rsh="ssh -p 8322" --bwlimit=100 --ipv4 .
    ruslan · 2011-02-10 14:25:22 2
  • Simple one-liner for scanning a range of hosts, you can also scan a range of ports with Netcat by ex.: nc -v -n -z -w 1 21-443 Useful when Nmap is not available:) Range declaration like X..X "for i in {21..29}" is only works with bash 3.0+ Show Sample Output

    for i in {21..29}; do nc -v -n -z -w 1 192.168.0.$i 443; done
    rez0r · 2009-09-25 03:31:29 3

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