tcpdump Cheat Sheet header

All the tables provided in the PDF and JPG of the cheat sheet are also presented in tables below which are easy to copy and paste.

The tcpdump cheat sheet covers:

  • Installation commands
  • Packet capturing options
  • Logical operators
  • Display/Output options
  • Protocols
  • Common commands with protocols for filtering captures

See also: 10 Best Packet Analyzers

View or Download the Cheat Sheet JPG image

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tcpdump cheat sheet

View or Download the cheat sheet PDF file

You can download the PDF file here. When it opens in a new browser tab, simply right click on the PDF and navigate to the download/save selection, usually located in the top right-hand corner of the screen.

What’s included in the cheat sheet

The following categories and items have been included in the cheat sheet:

Installation commands

Installation Commands


CENT OS and REDHAT


$ sudo yum install tcpdump


Fedora


$ dnf install tcpdump


Ubuntu, Debian and Linux Mint


#apt-get install tcpdump


Packet capturing options

Packet Capturing Options


Switch


Syntax


Description


-i any


tcpdump -i any


Capture from all interfaces


-i eth0


tcpdump -i eth0


Capture from specific interface ( Ex Eth0)


-c


tcpdump -i eth0 -c 10


Capture first 10 packets and exit


-D


tcpdump -D


Show available interfaces


-A


tcpdump -i eth0 -A


Print in ASCII


-w


tcpdump -i eth0 -w tcpdump.txt


To save capture to a file


-r


tcpdump -r tcpdump.txt


Read and analyze saved capture file


-n


tcpdump -n -I eth0


Do not resolve host names


-nn


tcpdump -n -i eth0


Stop Domain name translation and lookups (Host names or port names )


tcp


tcpdump -i eth0 -c 10 -w tcpdump.pcap tcp


Capture TCP packets only


port


tcpdump -i eth0 port 80


Capture traffic from a defined port only


host


tcpdump host 192.168.1.100


Capture packets from specific host


net


tcpdump net 10.1.1.0/16


Capture files from network subnet


src


tcpdump src 10.1.1.100


Capture from a specific source address


dst


tcpdump dst 10.1.1.100


Capture from a specific destination address


<service>


tcpdump http


Filter traffic based on a port number for a service


<port>


tcpdump port 80


Filter traffic based on a service


port range


tcpdump portrange 21-125


Filter based on port range


-S


tcpdump -S http


Display entire packet


ipv6


tcpdunp -IPV6


Show only IPV6 packets


-d


tcpdump -d tcpdump.pcap


display human readable form in standard output


-F


tcpdump -F tcpdump.pcap


Use the given file as input for filter


-I


tcpdump -I eth0


set interface as monitor mode


-L


tcpdump -L


Display data link types for the interface


-N


tcpdump -N tcpdump.pcap


not printing domian names


-K


tcpdump -K tcpdump.pcap


Do not verify checksum


-p


tcpdump -p -i eth0


Not capturing in promiscuous mode


Logical operators

Logical Operators


Operator


Syntax


Example


Description


AND


and, &&


tcpdump -n src 192.168.1.1 and dst port 21


Combine filtering options


OR


or, ||


tcpdump dst 10.1.1.1 && !icmp


Either of the condition can match


EXCEPT


not, !


tcpdump dst 10.1.1.1 and not icmp


Negation of the condition


LESS


<


tcpdump <32


Shows packets size less than 32


GREATER


>


tcpdump >=32


Shows packets size greater than 32


Display/Output options

Display / Output Options


Switch


Description


-q


Quite and less verbose mode display less details


-t


Do not print time stamp details in dump


-v


Little verbose output


-vv


More verbose output


-vvv


Most verbose output


-x


Print data and headers in HEX format


-xx


Print data with link headers in HEX format


-X


Print output in HEX and ASCII format excluding link headers


-XX


Print output in HEX and ASCII format including link headers


-e


Print Link (Ethernet) headers


-S


Print sequence numbers in exact format


Protocols

Protocols


Ether, fddi, icmp ,ip, ip6 , ppp, radio, rarp, slip, tcp , udp, wlan


Common commands with protocols for filtering captures

Common Commands with Protocols for Filtering Captures


src/ dsthost (host name or IP)


Filter by source or destination IP address or host


ether src/ dst host (ethernet host name or IP)


Ethernet host filtering by source or destination


src/ dstnet (subnet mask in CIDR)


Filter by subnet


tcp/udp src/dst port ( port number)


Filter TCP or UDP packets by source or destination port


tcp/udp src/dst port range ( port number range)


Filter TCP or UDP packets by source or destination port range


ether/ip broadcast


Filter for Ethernet or IP broadcasts


ether/ip multicast


Filter for Ethernet or IP multicasts