/How to be a network adminstrator – I

How to be a network adminstrator – I

Al salam 3likom .. 🙂
I will make Network series , will cover basic networking utilities and configuration commands .
Prerequisites :
You should have some background in History of network , TCP/IP , routers , FTP , HTTP , etc ..
Agenda for first package :
•    hostname
•    ping
•    ifconfig
•    iwconfig
•    ifup
•    ifdown
•    ethtool
•    arp
•    traceroute
•    tracepath
•    nslookup
•    dig
•    host
•    whois
1- hostname
•    Function : display system ‘s host name
•    Syntax :
$hostname
example

hostname used to display the name assigned to the local system such above the local system in my pc named by aboelfetouh  .

2- ping

  • Function : send an ICMP echo message to betwork host . Using ping comand to ping network host .
  • Syntax :

$ ping  [option] [Host]
$ ping -c [num] [Host]  send a specified number of ICMP packets .
example

We here using ping to ping 10.0.0.2 Host . This can be helpful when troubleshooting network connectivity problems  . in Output we find four ICMP messages received by 10.0.0.2 host ,So it is connected .
We cand stop ping with with CTRL + C
3 – ifconfig

  • Function : print network interfaces !

Network interfaces such as ethernet card it is display IP , MAC , ….
 

  • Syntax :

$ ifconfig
example

eth0 means ethernet card . We can make this
$ifconfig -a                              #display all interfaces
we notice that there is eth0 and wlan0 ,wlan  means wireless interface .
4– iwconfig

  • Function : Display wireless network interfaces .
  • Syntax :

$ iwconfig
 
example

but I have not wirless connections , But if their it will show a specific information of wireless network.
5- ifup

  • Function : enables a network interface .
  • Syntax :

# ifup [interface]
note : that command must make by admin [#]
example
# ifup eth0
6- ifdown

  • Function : disable a network interface .
  • Syntax :

# ifdown [interface]
example
# ifdown eth0
be careful with this 😀
7- ethtool

  • Function : display ethernet card settings.
  • Syntax :

# ethtool [ethernet card]
example
 

8- arp

  • Function : display arp cache
  • Syntax :

$ arp [option]
example

Local network use arp communicate with neighboring system , arp matches IPs with MAC address of destination address
arp cache : is that table that contain resolved address .
9- traceroute

  • Function : Display Tcp/IP routing information
  • Syntax

$ traceroute [Host]
$ traceroute [option] [Host]
example

bu by default each setp should determine one hop on the path . In TCP/IP  route more than hops , we use traceroute to know hops in the path
10- tracepath

  • Function : Display information on linux system
  • Syntax

$ tracepath [Host]
example

11- nslookup

  • Function : display Dns lookups for aspecific host
  • Syntax

$ nslookup [Host]
example

make view if IP , Address and troubleshoot address
12- dig

  • Function : modern replacement of nslookup
  • Syntax

$ dig [Host]
example
13- host

  • Function : such as nslookup and dig ,But it provide it in easier and readable view
  • Syntax

$ host [Host]
example

14- whois

  • Function : lookup domain name registration information
  • Syntax

$ whois [Host]
example

output

etc ..

wait the upcoming package  isA 🙂