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Modern way to show current IP address(es) in Linux
Answer:
In the past we already showed that you can get the IP information using the command "ifconfig", actually the modern way to do the job is
# ip a
1: lo: mtu 16436 qdisc noqueue state UNKNOWN
..
2: eth0: mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:26:5e:3e:42:d2 brd ff:ff:ff:ff:ff:ff
..
How to add a static route using command
Answer:
To add a static route, you can use a simple command like:
# sudo route add 192.168.15.0/24 192.168.1.1
The above command make all request to 192.168.15.0/24 (i.e. 192.168.15.1 to 192.168.15.254) route thru the gateway 192.168.1.1
How to show current routing table
Answer:
To show the current system's routing table, you can try:
# sudo netstat -nr
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
0.0.0.0 102.147.87.1 0.0.0.0 UG 0 0 0 eth0
0.0.0.0 102.147.45.1 0.0.0.0 UG 0 0 0 eth0
102.147.45.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
102.147.87.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
Network sniffing with tcpflow
Answer:
Wireshark is the De facto standard in network sniffing, but most of the time you might just want to analyse the content passing through your web browser or web server, then it is easy with tcpflow
For example, to show your communication with google.com to console, you can use
sudo tcpflow -c -i en0 src or dst host www.google.com
Renew DHCP IP address in Ubuntu
Answer:
To rename an IP address using DHCP in Ubuntu, try enter the commands below:
1. Release the current IP
# sudo dhclient -r2. Renew a new IP
# sudo dhclient