Linux Commands - network

* vncpasswd - create a passwd for the vnc server.
* vncserver - create x-window display so that vncclient can remote login. Example: "vncserver :10 -geometry 1280x960" create a display :10 with size 1280x960. "vncserver -kill :10" stops the display :10.
* ftp - connect to a ftp server and is useful to manage your webpage hosting site. Example."ftp youracount.x10hosting.com".
* telnet - remote login to a host, not secure, use ssh instead.
* ssh - open an ssh session on a remote host. Example: "ssh guy@192.168.1.100" will login host 192.168.1.100 with user guy.
* scp - copy files from/to remote host using ssh. Example: "scp guy@192.168.1.100:test.txt /some/local/directory/" will copy file test.txt from site 192.168.1.100 to local machine.
* wget - Retrieve web pages or files via HTTP, HTTPS or FTP. Example: "wget http://www.google.com/index.html" will download the webpage index.html from google site.

* netstat - powerful network debug tool. Example: "netstat" displays all sockets. "netstat -r" displays routing table. "netstat -s" displays summary of protocols.
* ping - ping a remote host. Example: "ping -c 3 www.google.com" send 3 ping packets to google.
* traceroute - trace the route to a remote host. Example "traceroute www.google.com" will find all the router hops to google.
* iptables - administration tool for IPv4 packets filtering and NAT. Exmple: "iptables -l" list all rules for all chains.

* write - send message to a user loging into the machine. Example: "send guy" will open a sending box to pass a message to user guy. Control + D to close the message window.
* mail - send smtp mail. You should have a MTA such as postfix installed on your host in order to send mail. Example: "echo This will go into the body of the mail. | mail -s “Hello world” you@youremailid.com".

* hostname - display or set the host name for local machine.
* host - simple dns loop up. Example: "host www.google.com" get the ip address of google. "host 204.228.150.3" reverse loop up the domain for ip address.
* dig - detailed dns look up. Example: "dig kl2217.x10hosting.com" shows the A, CNAME, NS records of the dns loopup. "dig kl2217.x10hosting.com MX" shows the mail server loopup records.
* nslookup - interactive dns look up tool.