Let me know how 'port' sensor works. What is a way to check port state? 'netstat' or 'telnet' command?
On what basis will port be checked whether 'open' or 'closed' in TCP session?
For example, When I used the command 'netstat' in cmd for checking 1433 port state as below, PRTG 'port' sensor can check the keyword 'ESTABLISHED' or 'LISTENING' ?
------------------------------------------------------------------------------------------------- C:\Users\Administrator>netstat -ano|findstr 1433 TCP 0.0.0.0:1433 0.0.0.0:0 LISTENING 2324 TCP 127.0.0.1:49212 127.0.0.1:1433 TIME_WAIT 0 TCP 127.0.0.1:49236 127.0.0.1:1433 TIME_WAIT 0 TCP 127.0.0.1:49263 127.0.0.1:1433 TIME_WAIT 0 TCP 127.0.0.1:49288 127.0.0.1:1433 TIME_WAIT 0 TCP 192.168.0.42:1433 192.168.0.188:58546 ESTABLISHED 2324 TCP 192.168.0.42:1433 192.168.0.200:59802 ESTABLISHED 2324 TCP 192.168.0.42:49213 192.168.0.153:1433 TIME_WAIT 0 TCP 192.168.0.42:49219 192.168.0.153:1433 TIME_WAIT 0 TCP 192.168.0.42:49237 192.168.0.153:1433 TIME_WAIT 0 TCP 192.168.0.42:49245 192.168.0.153:1433 TIME_WAIT 0 TCP 192.168.0.42:49267 192.168.0.153:1433 TIME_WAIT 0 TCP 192.168.0.42:49271 192.168.0.153:1433 TIME_WAIT 0 TCP 192.168.0.42:49289 192.168.0.153:1433 TIME_WAIT 0 TCP 192.168.0.42:49297 192.168.0.153:1433 TIME_WAIT 0 TCP [::]:1433 [::]:0 LISTENING 2324 -------------------------------------------------------------------------------------------------
Article Comments
Hi,
Does PRTG run the telnet command directly on the cmd?
(example) > telnet 8.8.8.8 3389
Jan, 2020 - Permalink
Hi Jonathan,
The sensor uses the service and doesn't run it directly in the cmd.
Kind regards.
Jan, 2020 - Permalink
Hi,
The Port sensor only uses telnet and the sensor can check if the port is open or closed.
You'll find more information about the Port sensor here.
Kind regards.
Oct, 2019 - Permalink