For more information about how to view network commands in ubuntu, see

For commands related to viewing networks in ubuntu, refer to querying Nic addresses by IP address (arping IP address) Checking computer name nmblookup-a ip address (ifconfig eth0 | awk '/inet/{split ($2, x ,":"); print x [2]} 'view the IP address w3m-no-cookie-dump www.123cha.com | grep-o' [0-9]/{1, 3/}/of the current Internet /}/. [0-9]/{1, 3 /}/. [0-9]/{1, 3 /}/. [0-9]/{1, 3/} 'w3m-no-cookie-dump ip.loveroot.com | grep-O' [0-9]/{1, 3 /}/. [0-9]/{1, 3 /}/. [0-9]/{1, 3 /}/. [0-9]/{/} 'to view the program lsof-I listening for port 80: 80 view the physical address of the current Nic ifconfig eth0 | head-1 | awk '{print $5}' add a second IP address for the same Nic # Add a 1.2.3.4 IP address on the NIC eth0: sudo ifconfig eth0: 0 1.2.3.4 netmask 255.255.255.0 # Delete the added IP: sudo ifconfig eth0: 0 down immediately enable the network to support nat echo 1 | sudo tee/proc/sys/net/ipv4/ip_forward sudo iptables-t nat-I POSTROUTING-j MASQUERADE view route information netstat-rn sudo route-n manually add a route sudo route add-net 192.168.0.0 netmask 255.255.255.0 gw 172.16.0.1 manually delete a route sudo route del-net 192.168.0.0 netmask 255.255.255.0 gw 172.16.0.1 how to modify the nic mac address sudo ifconfig eth0 down # disable sudo ifconfig eth0 hw ether 00: AA: BB: CC: DD: EE # Then change the sudo ifconfig eth0 up # then start the permanent address change method for the NIC sudo gedit/etc/network/interfaces and add a line after iface eth0 inet static: pre-up ifconfig eth0 hw ether 01: 01: 01: 01: 01: 01 the configuration file should be like the following iface eth0 inet static pre-up ifconfig eth0 hw ether 01: 01: 01: 01: 01: 01 address 192.168.1.10 netmask 255.255.255.0 gateway 192.168.1.1 the last is logout or reboot statistics on the number of current IP connections netstat-na | grep ESTABLISHED | awk '{print $5}' | awk-F: '{print $1}' | sort | uniq-c | sort-r-n netstat-na | grep SYN | awk '{print $5}' | awk-F: '{print $1}' | sort | uniq-c | sort-r-n: the IP address tcpdump-tnn-c 20000-I eth0 of the current 100 IP Packets | awk-F ". "'{print $1 ". "$2 ". "$3 ". "$4} '| sort | uniq-c | sort-nr | awk' $1> 100 'blocked IPV6echo" blacklist ipv6 "| sudo tee/etc/modprobe. d/blacklist-ipv6 view current network connection status and program sudo netstat-atnp view network connection status netstat-n | awk '/^ tcp/{++ S [$ NF]} END {(a in S) print, S [a]} 'view all the listening ports of the current system nc-zv localhost 1-65535 view the current network traffic # install ethstatus software sudo apt-get install ethstatus # view the ADSL speed sudo ethstatus -I ppp0 # view the speed of the NIC sudo ethstatus-I eth0 # or install bwm-ng sudo apt-get install bwm-ng # view the current network traffic bwm-ng to view the domain name registration record whois baidu.cn view the Routing Status of a domain name tracepath baidu.cn re-obtain the IP address sudo dhclient from the server