---
name: "tcptracer-bpfcc"
section: "8"
platform: "linux"
package: "bpfcc-tools"
version: "0.31.0+ds-7"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/tcptracer-bpfcc"
---

# tcptracer-bpfcc(8)

Trace TCP established connections. Uses Linux eBPF/bcc.

## NAME

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

## SYNOPSIS

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

## DESCRIPTION

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.

## REQUIREMENTS

CONFIG\_BPF and bcc.

## OPTIONS

- \-h

  Print usage message.

- \-v

  Print full lines, with long event type names and network namespace numbers.

- \-t

  Include timestamp on output

- \-p PID

  Trace this process ID only (filtered in-kernel).

- \-N NETNS

  Trace this network namespace only (filtered in-kernel).

- \--cgroupmap MAPPATH

  Trace cgroups in this BPF map only (filtered in-kernel).

- \--mntnsmap MAPPATH

  Trace mount namespaces in the map (filtered in-kernel).

- \-4

  Trace IPv4 family only.

- \-6

  Trace IPv6 family only.

## EXAMPLES

- Trace all TCP established connections:

  \# **tcptracer**

- Trace all TCP established connections with verbose lines:

  \# **tcptracer -v**

- Trace PID 181 only:

  \# **tcptracer -p 181**

- Trace connections in network namespace 4026531969 only:

  \# **tcptracer -N 4026531969**

- Trace a set of cgroups only (see special\_filtering.md from bcc sources for more details):

  \# **tcptracer --cgroupmap /sys/fs/bpf/test01**

- Trace IPv4 family only:

  \# **tcptracer -4**

- Trace IPv6 family only:

  \# **tcptracer -6**

## FIELDS

- TYPE

  Type of event. In non-verbose mode: C for connect, A for accept, X for close.

- PID

  Process ID

- COMM

  Process name

- IP

  IP address family (4 or 6)

- SADDR

  Source IP address.

- DADDR

  Destination IP address.

- SPORT

  Source port.

- DPORT

  Destination port.

- NETNS

  Network namespace where the event originated.

## OVERHEAD

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.

## SOURCE

This is from bcc.

-

  https://github.com/iovisor/bcc

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

## OS

Linux

## STABILITY

Unstable - in development.

## AUTHOR

Iago López Galeiras

## SEE ALSO

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