Demonstrations of tcpv4connect.py, the Linux eBPF/bcc version. This example traces the kernel function performing active TCP IPv4 connections (eg, via a connect() syscall; accept() are passive connections). Some example output (IP addresses changed to protect the innocent): # ./tcpv4connect.py PID COMM SADDR DADDR DPORT 1479 telnet 127.0.0.1 127.0.0.1 23 1469 curl 10.201.219.236 54.245.105.25 80 1469 curl 10.201.219.236 54.67.101.145 80 This output shows three connections, one from a "telnet" process and two from "curl". The output details shows the source address, destination address, and destination port. This traces attempted connections: these may have failed. The overhead of this tool should be negligible, since it is only tracing the kernel function performing a connect. It is not tracing every packet and then filtering. This is provided as a basic example of TCP tracing. See tools/tcpconnect for a more featured version of this example (a tool).