tcpping


This script is a crude emulation of the well known ping command, except it uses TCP SYN packets. If I get enough feedback I will add features like percentage packet loss and round-trip min/avg/max to it.

This script requires the excellent tcptraceroute written by Michael C. Toren.

The script is called tcpping, the current version is 1.6. Some example output:

$ tcpping www.cisco.com
seq 0: tcp response from www.cisco.com (198.133.219.25) [open]  155.513 ms
seq 1: tcp response from www.cisco.com (198.133.219.25) [open]  148.907 ms
seq 2: tcp response from www.cisco.com (198.133.219.25) [open]  153.686 ms
seq 3: tcp response from www.cisco.com (198.133.219.25) [open]  150.864 ms
seq 4: tcp response from www.cisco.com (198.133.219.25) [open]  147.917 ms
$ tcpping -d www.cisco.com
Fri Dec 20 15:59:27 MET 2002
seq 0: tcp response from www.cisco.com (198.133.219.25) [open]  159.006 ms
Fri Dec 20 15:59:29 MET 2002
seq 1: tcp response from www.cisco.com (198.133.219.25) [open]  148.594 ms
Fri Dec 20 15:59:30 MET 2002
seq 2: tcp response from www.cisco.com (198.133.219.25) [open]  148.394 ms
Fri Dec 20 15:59:31 MET 2002
seq 3: tcp response from www.cisco.com (198.133.219.25) [open]  150.787 ms
Fri Dec 20 15:59:32 MET 2002
$ tcpping -c www.cisco.com
0 1043546228 201.304 www.cisco.com (198.133.219.25)
1 1043546229 195.810 www.cisco.com (198.133.219.25)
2 1043546230 186.759 www.cisco.com (198.133.219.25)
3 1043546231 201.614 www.cisco.com (198.133.219.25)
4 1043546232 245.070 www.cisco.com (198.133.219.25)
5 1043546233 246.764 www.cisco.com (198.133.219.25)

Using the -c switch and this gnuplot script you can produce nice graphs like this: