Common commands in Linux

Use a script to include these commonly used linux network operation commands.

#/bin/sh

# Viewing http request headers

tcpdump -s 1024 -l -A -n host 192.168.9.56tcpdump -s 1024 -l -A src 192.168.9.56 or dst 192.168.9.56sudo tcpdump -A -s 1492 dst port 80

# The host with the IP address 192.168.0.5 in the local network now communicates with the outside world

sudo tcpdump -i eth0 src host 192.168.0.5

# View the tcp packet of the http request of the network adapter eth0

tcpdump -i eth0 port httptcpdump -i eth0 port http or port smtp or port imap or port pop3 -l -A | egrep -i 'pass=|pwd=|log=|login=|user=|username=|pw=|passw=|passwd=|password=|pass:|user:|userna me:|password:|login:|pass |user '

# View tcp, upd, and icmp non-ssh packets

tcpdump -n -v tcp or udp or icmp and not port 22

# View the http request package

sudo tcpdump -i eth0 port 80 -w -

# Filter the http Response's get host header information

sudo tcpdump -i en1 -n -s 0 -w - | grep -a -o -E "GET \/.*|Host\: .*"

# DNS query request response package

sudo tcpdump -i en0 'udp port 53'

# Nmap-sP specify to use Ping echo for scanning/24 to view how many hosts in the target network are running

nmap -sP 192.168.0.1nmap -sP 192.168.0.0/24nmap -O www.baidu.com

# Netstat is mainly used for Linux/Unix hosts to view their network conditions, such as the opened ports, the user services and service statuses.

netstat -anetstat -nlp

# Netcat scan ports opened by machines

nc -z -v -n 172.31.100.7 21-25

# The netcat command will connect to open port 21 and print the banner information of the Service running on this port.

nc -v 172.31.100.7 21

# Route table of the output Network

route

# The result shows how long the server has been running, how many login users are there, and the overall load average evaluation of server performance ).

uptime

# Monitor the network card Traffic of eth1

iftop -i eth1

# Display traffic in bytes (bytes) (default: bits ):

iftop -B

# Directly display the IP address without reverse DNS resolution:

iftop -n

# The Connection port number is displayed directly, but the service name is not displayed:

iftop -N

# Display inbound and outbound traffic of a CIDR Block

iftop -F 192.168.1.0/24 or 192.168.1.0/255.255.255.0

# Nload, a real-time network traffic monitoring tool, to view the eth0 traffic of the Network Adapter

nload -n eth0

# View the traffic of each Nic

nload -h

# IPTraf is a network monitoring tool with more powerful functions than nload. It can monitor all traffic, IP traffic, protocol-based traffic, and set filters.

iptraf

# View the current configuration of the network interface and the interface Name:

ifconfig

# Open up) or close down) Adapter

Ifconfig <Network Name> <up | down>

# Assign an IP address to the adapter:

Ifconfig <Network Name> <IP address>

# Assign a second IP address to the adapter:

Ifconfig <Network Name: number of instances> <IP address>

# Display the driver information of a network adapter, which is suitable for querying software compatibility:

ethtool -i eth0

# Display network data:

ethtool -S

# Set the adapter connection speed (Mbps)

ethtool speed <10|100|1000>

# Iwconfig check basic Wi-Fi network settings, such as SSID, channel, and encryption. You can also modify some advanced settings, including the receipt sensitivity, RTS/CTS, fragments, and number of retries.

# Display the current wireless settings, including the Interface Name:

iwconfig

# Set the ESSID extension service to set the identifier) or network name:

Iwconfig <Interface Name> essid <Network Name>

#wgetwget -S --spider http://osswin.sourceforge.net/ 2>&1 | grep Mod

# View mac addresses

cat /sys/class/net/*/address

# View the ip address of eth0

ifconfig eth0 | awk '/inet addr/ {split ($2,A,":"); print A[2]}'

# Curl: view the domail name corresponding to the page

curl -s http://en.m.wikipedia.org/wiki/List_of_Internet_top-level_domains | sed -n '/<tr valign="top">/{s/<[^>]*>//g;p}'#talnettelnet localhost 6666

# View all network interfaces

awk '{print $1}' /proc/net/dev|grep :|sed "s/:.*//g"

# Viewing the DNS server version

nslookup -q=txt -class=CHAOS version.bind NS.PHX5.NEARLYFREESPEECH.NET