====== NETWORK - Fu ======

Check to see what is running on a specific port number

<code bash>
sudo netstat -tulpn | grep :8080
</code>

Showing opened ports on machine

<code bash>
netstat -tulpnc
</code>

List services running on each open port

<code bash>
nmap -T Aggressive -A -v 127.0.0.1 -p 1-65000
</code>

Ping 10 times then quit

<code bash>
ping -c 10 hostname
</code>

Ping a host until it responds, then play a sound, then exit

<code bash>
beepwhenup () { 
    echo 'Enter host you want to ping:'; 
    read PHOST; 
    if [[ "$PHOST" == "" ]]; then 
        exit; 
    fi; 
    while true; do 
        ping -c1 -W2 $PHOST 2>&1 >/dev/null; 
        if [[ "$?" == "0" ]]; then 
            for j in $(seq 1 4); do 
                beep; 
            done; 
            ping -c1 $PHOST; 
            break; 
        fi; 
    done; 
}
</code>

Ping a host until it responds, then play a sound, then exit

<code sh>
speakwhenup() { [ "$1" ] && PHOST="$1" || return 1; until ping -c1 -W2 $PHOST >/dev/null 2>&1; do sleep 5s; done; espeak "$PHOST is up" >/dev/null 2>&1; }
</code>

Ping all hosts on 192.168.1.0/24

<code sh>
for i in {0..255} ; do (ping 192.168.1.$i -c 1  > /dev/null && echo "192.168.1.$i" & ) ; done
</code>

Ping all hosts on 192.168.1.0/24

<code bash>
fping -ga 192.168.1.0/24 2> /dev/null
</code>

Ping all hosts on 192.168.1.0/24

<code bash>
nmap -sn 192.168.1.0/24
</code>

Ping a range of addresses

<code bash>
nmap -sP -T Insane 192.168.1.1-254
</code>

Ping as traceroute

<code bash>
mtr google.com
</code>

Ping a URL sending output to file and STDOUT

<code bash>
ping google.com | tee ping-output.txt
</code>

Script broadcast-pppoe-discover

<code bash>
nmap -T4 --script broadcast-pppoe-discover 192.168.122.0/24
</code>

The NMAP command you can use scan for the Conficker virus on your LAN

<code bash>
nmap -PN -T4 -p139,445 -n -v --script=smb-check-vulns --script-args safe=1 192.168.0.1-254
</code>

Use a decoy while scanning ports to avoid getting caught by the sys
admin :9

<code bash>
sudo nmap -sS 192.168.0.10 -D 192.168.0.2
</code>

Install NMAP 5.0 ,Short and sweet command to do it

<code bash>
sudo wget -c "http://nmap.org/dist/nmap-5.00.tar.bz2" && bzip2 -cd nmap-5.00.tar.bz2 | \
tar xvf - && cd nmap-5.00 && ./configure && make && sudo make install
</code>

Cleanly list available wireless networks (using iwlist)

<code bash>
iwlist wlan0 scan | sed -ne 's#^[[:space:]]*\(Quality=\|Encryption key:\|ESSID:\)#\1#p' -e 's#^[[:space:]]*\(Mode:.*\)$#\1\n#p'
</code>

Find out what is using the bandwidth

<code bash>
nethogs
</code>

How to speedup the Ethernet device

<code bash>
sudo ethtool -s eth0 speed 100 duplex full
</code>

Obtain ip

<code bash>
udhcpc -i eth0
</code>

Prevent an IPv6 address on an interface from being used as source
address of packets.

<code bash>
ip addr change 2001:db8:1:2::ab dev eth0 preferred_lft 0
</code>

Traffic stat on ethernet interface

<code bash>
ethtool -S eth0
</code>

Extraer la MAC del comando ifconfig

<code bash>
ifconfig eth0 | grep HW | cut -d " " -f 11
</code>

Print machine’s ipv4 addresses

<code bash>
echo $(ifconfig) | egrep -o "en.*?inet [^ ]* " | sed 's/.*inet \(.*\)$/\1/' | tail -n +2
</code>

Show local IP

<code bash>
ifconfig eth0 | grep "inet:" | cut -d ":" -f2 | cut -d " " -f1
</code>

Show WAN IP

<code bash>
curl ifconfig.me
</code>

Simple MAC Changeing

<code bash>
ifconfig wlan0 hw ether 00:11:22:33:44:55
</code>

Display ncurses based network monitor

<code bash>
nload -u m eth0
</code>

Does a traceroute. Lookup and display the network or AS names and AS
numbers.

<code bash>
lft -NAS google.com
</code>

Find installed network devices

<code bash>
sudo lshw -C network
</code>

Find errors and packet loss on network cards

<code bash>
ethtool -S eth0 | egrep "(drop|disc|err|fifo|buf|fail|miss|OOB|fcs|full|frags|hdr|tso).*: [^0]"
</code>

Get contents from hosts, passwd, groups even if they’re in DB/LDAP/other

<code bash>
getent [group|hosts|networks|passwd|protocols|services] [keyword]
</code>

Get current connected wireless network with nm-tools

<code bash>
nm-tool 2>/dev/null|sed -n '/Type:[ ]*802.11 WiFi/,/IPv4 Settings/{ /State:[ ]*connected/,/IPv4 Settings/{ s/^[ ]*//;/^\*.*Infra/ { s/^*//;s/:.*//;p } }}'
</code>

Getting a list of active addresses in your own network.

<code bash>
nmap -n -sP -oG - 10.10.10.*/32 | grep ": Up" | cut -d' ' -f2
</code>

Highlight network TX, RX information change

<code bash>
watch -n 2 -d '/sbin/ifconfig eth0'
</code>

Identify active network connections

<code bash>
lsof -i -P +c 0 +M | grep -i "$1"
</code>

Investigates the network connection between the host and google public
dns server

<code bash>
mtr -t -o "LSD NBAW" 8.8.8.8
</code>

Make a server’s console beep when the network is down

<code bash>
while :; do ping -W1 -c1 -n 8.8.8.8 > /dev/null || tput bel > /dev/console; sleep 1; done
</code>

MTR command line to show jitter and mimic network traffic

<code bash>
sudo mtr -s 1472 -B 0 -oLDRSWNBAWVJMXI IP ADDRESS
</code>

Netstat -luntp

<code bash>
netstat -luntp
</code>

Network Information

<code bash>
ntop
</code>

Network Interfaces

<code bash>
ip link
netstat -ie
</code>

Network throughput test

<code bash>
iperf -s
</code>

Network usage per process

<code bash>
sudo nethogs eth0
</code>

Nmap list IPs in a network and saves in a txt

<code bash>
nmap -sP 192.168.1.0/24 | grep "Nmap scan report for"| cut -d' ' -f 5  > ips.txt
</code>

Nmap port scanning

<code bash>
nmap -v -sT 192.168.0.0/24
</code>

One liner to check out CLOSE\_WAIT and TIME\_WAIT connection every five
seconds while debugging network apps

<code bash>
while true; do netstat -a|grep WAIT|wc -l; sleep 5; done
</code>

Ping scan for a network and says who is alive or not

<code bash>
for i in `seq 254`;do ping -c 1 192.168.10.$i > /dev/null && echo "$i is up"||echo "$i is down";done
</code>

Ping scanning without nmap

<code bash>
for i in {1..254}; do ping -c 1 -W 1 10.1.1.$i | grep 'from'; done
</code>

Ping scanning without nmap

<code bash>
prefix="10.0.0" && for i in `seq 25`; do ping -c 1 $prefix.$i &> /dev/null && echo "Answer from: $prefix.$i" ; done
</code>

Ping sweep without NMAP

<code bash>
prefix="169.254" && for i in {0..254}; do echo $prefix.$i/8; for j in {1..254}; do sh -c "ping -m 1 -c 1 -t 1 $prefix.$i.$j | grep \"icmp\" &" ; done; done
</code>

Ping with timestamp

<code bash>
ping HOSTNAME | while read pong; do echo "$(date): $pong"; done
</code>

Check the status of a network interface

<code bash>
for i in `ls /sys/class/net/`; do echo $i: `cat /sys/class/net/$i/operstate`; done
</code>

Check the status of a network interface

<code bash>
mii-tool [if]
</code>

Restart network manager

<code bash>
sudo /etc/init.d/networking restart
</code>

Scan computers OS and open services on all network

<code bash>
nmap -O 192.168.1.1/24
</code>

Scan subnet for used IPs

<code bash>
nmap -T4 -sn 192.168.1.0/24
</code>

Share internet connection with only one network interface

<code bash>
ifconfig eth0:1 192.168.0.1/24
</code>

Show alive host on network

<code bash>
nmap -sP 192.168.0.* | grep Host | tr "(" ")" | cut -d\) -f2
</code>

Show all machines on the network

<code bash>
nmap 192.168.0-1.0-255 -sP
</code>

Show a running count of CLOSE\_WAIT and TIME\_WAIT connections for
debugging network apps

<code bash>
watch -n5 ss \| grep -c WAIT
</code>

Show established network connections

<code bash>
lsof -i | grep -i estab
</code>

Simulate slow network connection locally

<code bash>
sudo tc qdisc add dev lo root netem delay 500ms
</code>

Check if network cable is plugged in and working correctly

<code bash>
mii-tool eth0
</code>

Blink LED Port of NIC Card

<code bash>
ethtool -p eth0
</code>