SCAPY(1) General Commands Manual SCAPY(1)

# [NAME](#NAME)

scapy - Interactive packet manipulation tool

# [SYNOPSIS](#SYNOPSIS)

**scapy** \[*options*]

# [DESCRIPTION](#DESCRIPTION)

This manual page documents briefly the **Scapy** tool.

**Scapy** is a powerful interactive packet manipulation tool, packet generator, network scanner, network discovery, packet sniffer, etc. It can for the moment replace hping, parts of nmap, arpspoof, arp-sk, arping, tcpdump, tshark, p0f, ...

**Scapy** uses the Python interpreter as a command board. That means that you can use directly Python language (assign variables, use loops, define functions, etc.)

The idea is simple. Those kinds of tools do two things : sending packets and receiving answers. That's what **Scapy** does : you define a set of packets, it sends them, receives answers, matches requests with answers and returns a list of packet couples (request, answer) and a list of unmatched packets. This has the big advantage over tools like nmap or hping that an answer is not reduced to (open/closed/filtered), but is the whole packet.

On top of this can be used to build more high-level functions, for example, one that does traceroutes and give as a result only the start TTL of the request and the source IP of the answer. One that pings a whole network and gives the list of machines answering. One that does a portscan and returns a LaTeX report.

# [OPTIONS](#OPTIONS)

Options for Scapy are:

[**-h**](#h)

display usage

[**-H**](#H)

header-less mode, also reduces verbosity.

[**-d**](#d)

increase log verbosity. Can be used many times.

[**-p** PRESTART\_FILE](#p)

use PRESTART\_FILE instead of $HOME/.config/scapy/prestart.py as pre-startup file

[**-P**](#P)

do not run prestart file

[**-c** STARTUP\_FILE](#c)

use STARTUP\_FILE instead of $HOME/.config/scapy/startup.py as startup file

[**-C**](#C)

do not run startup file

# [COMMANDS](#COMMANDS)

Only the vital commands to begin are listed here for the moment.

[**ls()**](#ls%28%29)

lists supported protocol layers. If a protocol layer is given as parameter, lists its fields and types of fields. If a string is given as parameter, it is used to filter the layers.

[**lsc()**](#lsc%28%29)

lists scapy's main user commands.

[**conf**](#conf)

this object contains the configuration.

# [FILES](#FILES)

**$HOME/.config/scapy/prestart.py** This file is run before Scapy core is loaded. Only the **conf** object is available. This file can be used to configure the CLI, configure parameters such as the **conf.load\_layers** list to choose which layers will be loaded, or change the logging level (for instance):

```
conf.interactive_shell = "bpython"
log_loading.setLevel(logging.WARNING)
conf.load_layers.remove("bluetooth")
conf.load_layers.append("new_layer")
```

**$HOME/.config/scapy/startup.py** This file is run after Scapy is loaded. It can be used to configure more of Scapy behaviors, like un-registering layers:

```
conf.prog.pdfreader = "xpdf"
split_layers(UDP,DNS)
```

# [EXAMPLES](#EXAMPLES)

More verbose examples are available in the documentation at *https://scapy.readthedocs.io/*. Just run **scapy** and try the following commands in the interpreter.

Test the robustness of a network stack with invalid packets:

```
sr(IP(dst="172.16.1.1", ihl=2, options=["verb$2"], version=3)/ICMP(), timeout=2)
```

Packet sniffing and dissection (with a bpf filter or tshark-like output):

```
a=sniff(filter="tcp port 110")
a=sniff(prn = lambda x: x.show) 
```

Sniffed packet re-emission:

```
a=sniff(filter="tcp port 110")
sendp(a)
```

Pcap file packet re-emission:

```
sendp(rdpcap("file.cap"))
```

Manual TCP traceroute:

```
sr(IP(dst="www.google.com", ttl=(1,30))/TCP(seq=RandInt(), sport=RandShort(), dport=dport)
```

Protocol scan:

```
sr(IP(dst="172.16.1.28", proto=(1,254)))
```

ARP ping:

```
srp(Ether(dst="ff:ff:ff:ff:ff:ff")/ARP(pdst="172.16.1.1/24"))
```

ACK scan:

```
sr(IP(dst="172.16.1.28")/TCP(dport=(1,1024), flags="A"))
```

Passive OS fingerprinting:

```
sniff(prn=prnp0f) 
```

Active OS fingerprinting:

```
nmap_fp("172.16.1.232")
```

ARP cache poisoning:

```
sendp(Ether(dst=tmac)/ARP(op="who-has", psrc=victim, pdst=target))
```

Reporting:

```
report_ports("192.168.2.34", (20,30))
```

# [SEE ALSO](#SEE_ALSO)

```
The official website: https://scapy.net/
The GitHub Development repository: https://github.com/secdev/scapy/
The official documentation: https://scapy.readthedocs.io/en/latest/
```

# [BUGS](#BUGS)

Does not give the right source IP for routes that use interface aliases.

May miss packets under heavy load. This is a restriction from python itself

Session saving is limited by Python ability to marshal objects. As a consequence, lambda functions and generators can't be saved, which seriously reduce the usefulness of this feature.

BPF filters don't work on Point-to-point interfaces.

# [AUTHOR](#AUTHOR)

Philippe Biondi and the Scapy community.

March 24, 2024

---

Document: scapy(1) from scapy 2.8.0-r0 (Chainguard OS)
Source: https://github.com/secdev/scapy