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tcptracer(8) System Manager's Manual tcptracer(8)


tcptracer - Trace TCP established connections. Uses Linux eBPF/bcc.


tcptracer [-h] [-v] [-p PID] [-N NETNS] [--cgroupmap MAPPATH] [--mntnsmap MAPPATH] [-4 | -6]


This tool traces established TCP connections that open and close while tracing, and prints a line of output per connect, accept and close events. This includes the type of event, PID, IP addresses and ports.

This tool works by using kernel dynamic tracing, and will need to be updated if the kernel implementation changes. Only established TCP connections are traced, so it is expected that the overhead of this tool is rather low.

Since this uses BPF, only the root user can use this tool.


CONFIG_BPF and bcc.


Print usage message.
Print full lines, with long event type names and network namespace numbers.
Trace this process ID only (filtered in-kernel).
Trace this network namespace only (filtered in-kernel).
Trace cgroups in this BPF map only (filtered in-kernel).
Trace mount namespaces in the map (filtered in-kernel).
Trace IPv4 family only.
Trace IPv6 family only.


# tcptracer
# tcptracer -v
# tcptracer -p 181
# tcptracer -N 4026531969
# tcptracer --cgroupmap /sys/fs/bpf/test01
# tcptracer -4
# tcptracer -6


Type of event. In non-verbose mode: C for connect, A for accept, X for close.
Process ID
Process name
IP address family (4 or 6)
Source IP address.
Destination IP address.
Source port.
Destination port.
Network namespace where the event originated.


This traces the kernel inet accept function, and the TCP connect, close, and set state functions. However, it only prints information for connections that are established, so it shouldn't have a huge overhead.

As always, test and understand this tools overhead for your types of workloads before production use.


This is from bcc.

Also look in the bcc distribution for a companion _examples.txt file containing example usage, output, and commentary for this tool.




Unstable - in development.


Iago López Galeiras


tcpaccept(8), tcpconnect(8), tcptop(8), tcplife(8)

2020-02-20 USER COMMANDS