Linux Ask! is a Q & A web site specific for Linux related questions. Questions are collected, answered and audited by experienced Linux users.
How to kill a TCP connection using tcpkill?
Answer:
You can use the tcpkill program.
tcpkill came with the dsniff in Debian/Ubuntu, you need to install it manually.
# sudo apt-get install dsniff
Usages:
1. Kill all outgoing web (port 80) connection:
# tcpkill -i eth0 port 80
2. Kill all connection by IP
# tcpkill -i eth0 host www.google.com
How to change MAC address
Answer:
To change MAC address, you need to take the network interface
# sudo ifconfig eth1 down
Then change it by
# sudo ifconfig eth1 hw ether 00:01:02:03:04:05
Kill all processes listening on a particular port
Answer:
To kill all processes listening on a particular port, e.g. port 80
# kill -9 $( lsof -i:80 -t )
Replace 80 by the port you want.
Packet sniffing with tcpdump
Answer:
To perform packet sniffing, it is easy with tcpdump
# tcpdump -i eth0 -w dump.cap -s 0After you terminated the tcpdump, you can use tool such as Wireshark to analyse the dump.cap.
Show the system ARP cache
Answer:
Show the current content of the current ARP table
# arp
Address HWtype HWaddress Flags Mask Iface
192.168.1.5 ether 00:00:0c:07:ac:0c C eth0
