TcpDump. How do I view the traffic coming to a specific port?
There is a simulator of a geodata transfer device operating over TCP/IP. This simulator is located on a remote server and sends data to a specific machine over the Internet (using ip + port). The customer said that he will configure the simulator so that it sends messages to our server on a specific port. I need to somehow see if any traffic passes through this port or not.
The server runs on CentOS. The system administrator said that he opened I opened the port and threw it on this car. I'm trying to use tcpdump. I enter the command:
# tcpdump port 9000
What I see in the console:
Tcpdump: NFLOG link-layer type filtering not implemented
Please tell me what you need to do to find out if there is traffic on a certain port number. I'm not good at system administration.
1 answers
In the comments, @Mike gave the correct command syntax. You had to specify the name of the network device. As a result, the command looks like this:
tcpdump -i ens33 port 9000