Setting ip address linux centos

1.Yang jelas harus Login dengan user root :D
2.Ubah Script eth0 di folder /etc/sysconfig/network-script/

[root@centos ~]#cd /etc/sysconfig/network-script/
[root@centos network-script]#

[root@centos network-script]#vi ifcfg-eth0

Kemudian isikan dengan skrip berikut ini :

DEVICE=eth0
BOOTPROTO=static
BROADCAST=192.168.1.255
IPADDR=192.168.1.128
NETMASK=255.255.255.0
NETWORK=192.168.1.0
ONBOOT=yes
TYPE=Ethernet

simpan dan keluar dengan menggunakan :wq

3.Edit file konfigurasi default gateway yang ada pada folder /etc/syconfig

[root@centos network-script]#cd /etc/sysconfig
[root@centos sysconfig]#vi network
isikan dengan skrip berikut ini
NETWORKING=yes
HOSTNAME=localhost.localdomain
GATEWAY=192.168.1.1
simpan dan keluar dengan menggunakan :wq

2.Edit file resolv.conf yang digunakan untuk menyimpan data dns

[root@centos network-script]#cd /etc/
[root@centos etc]#vi resolv.conf

Kemudian isikan dengan skrip berikut ini
nameserver 192.168.1.1
nameserver 202.134.0.155

simpan dan keluar dengan menggunakan :wq

6.Restart network.
[root@centos etc]#/etc/init.d/network restart

7.Cek IP yang sudah terinstall pada Ethernet
[root@centos etc]#ifconfig
eth0 Link encap:Ethernet HWaddr 00:50:56:A4:00:08
inet addr:192.168.1.128 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::230:18ff:fea4:e06f/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:81548 errors:0 dropped:0 overruns:0 frame:0
TX packets:74945 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:68397087 (65.2 MiB) TX bytes:8293763 (7.9 MiB)
Interrupt:201 Base address:0×6000

Install Nmap dan cara penggunaannya

Nmap (Network Mapper) adalah sebuah tools scanner keamanan yang awalnya ditulis oleh Gordon Lyon dan digunakan untuk menemukan host dan layanan di jaringan komputer, sehingga membuat peta jaringan. Nmap berjalan pada Linux, Microsoft Windows, Solaris, HP-UX dan varian BSD (termasuk Mac OS X), dan juga pada AmigaOS dan SGI IRIX [2] Linux. Adalah platform yang paling populer nmap dengan Windows berikut dengan cermat. Cara untuk install nmap di Ubuntu sangatlah mudah, cuma melakukan download dari internet seperti perintah di bawah :

user@user-laptop:~$ sudo apt-get install nmap
[sudo] password for user:
Reading package lists… Done
Building dependency tree
Reading state information… Done
The following packages were automatically installed and are no longer required:
linux-headers-2.6.32-21 linux-headers-2.6.32-21-generic
Use ‘apt-get autoremove’ to remove them.
The following extra packages will be installed:
liblua5.1-0
The following NEW packages will be installed:
liblua5.1-0 nmap
0 upgraded, 2 newly installed, 0 to remove and 29 not upgraded.
Need to get 1,671kB of archives.
After this operation, 6,541kB of additional disk space will be used.
Do you want to continue [Y/n]? y
Get:1 http://id.archive.ubuntu.com/ubuntu/ lucid/main liblua5.1-0 5.1.4-5 [82.2kB]
Get:2 http://id.archive.ubuntu.com/ubuntu/ lucid/main nmap 5.00-3 [1,589kB]
Fetched 1,671kB in 5s (303kB/s)
Selecting previously deselected package liblua5.1-0.
(Reading database … 149317 files and directories currently installed.)
Unpacking liblua5.1-0 (from …/liblua5.1-0_5.1.4-5_i386.deb) …
Selecting previously deselected package nmap.
Unpacking nmap (from …/archives/nmap_5.00-3_i386.deb) …
Processing triggers for man-db …
Setting up liblua5.1-0 (5.1.4-5) …
Setting up nmap (5.00-3) …
Processing triggers for libc-bin …
ldconfig deferred processing now taking place
to run nmap to scan ip address with range 10.10.28.0 – 10.10.28.254, you just run command :

user@user-laptop:~$ nmap -sP 10.10.28.0/24
and the result :
Starting Nmap 5.00 ( http://nmap.org ) at 2010-08-30 17:23 WIT
Host 10.10.28.1 is up (0.00025s latency).
Host 10.10.28.3 is up (0.00032s latency).
Host 10.10.28.7 is up (0.000098s latency).
Host 10.10.28.9 is up (0.00022s latency).
Host 10.10.28.21 is up (0.00032s latency).
Host 10.10.28.22 is up (0.00030s latency).
Host 10.10.28.41 is up (0.0012s latency).
Host 10.10.28.42 is up (0.0011s latency).
Host 10.10.28.43 is up (0.0010s latency).
Host 10.10.28.44 is up (0.0010s latency).
Host 10.10.28.45 is up (0.0013s latency).
Host 10.10.28.46 is up (0.0012s latency).
Host 10.10.28.47 is up (0.0016s latency).
Host 10.10.28.48 is up (0.0015s latency).
Host 10.10.28.49 is up (0.0015s latency).
Host 10.10.28.50 is up (0.0015s latency).
Host 10.10.28.51 is up (0.0012s latency).
Host 10.10.28.100 is up (0.012s latency).
Host 10.10.28.105 is up (0.0041s latency).
Host 10.10.28.131 is up (0.0041s latency).
Nmap done: 256 IP addresses (20 hosts up) scanned in 2.36 seconds
Port Scanning with range 100-150

user@user-laptop:~$ nmap 10.10.28.22 -p100-150
Starting Nmap 5.00 ( http://nmap.org ) at 2010-08-30 17:33 WIT
Interesting ports on 10.10.28.22:
Not shown: 49 closed ports
PORT STATE SERVICE
135/tcp open msrpc
139/tcp open netbios-ssn
Nmap done: 1 IP address (1 host up) scanned in 1.16 seconds
for Scan Operating System :
user@user-laptop:~$ sudo nmap 10.10.28.22 -O
Starting Nmap 5.00 ( http://nmap.org ) at 2010-08-30 17:35 WIT
Interesting ports on 10.10.28.22:
Not shown: 988 closed ports
PORT STATE SERVICE
135/tcp open msrpc
139/tcp open netbios-ssn
445/tcp open microsoft-ds
3389/tcp open ms-term-serv
5101/tcp open admdog
49152/tcp open unknown
49153/tcp open unknown
49154/tcp open unknown
49155/tcp open unknown
49156/tcp open unknown
49157/tcp open unknown
49160/tcp open unknown
MAC Address: 00:04:4B:16:59:89 (Nvidia)
Device type: general purpose
Running: Microsoft Windows Vista|2008|7
OS details: Microsoft Windows Vista SP0 or SP1, Server 2008, or Windows 7 Ultimate (build 7000)
Network Distance: 1 hop
OS detection performed. Please report any incorrect results at http://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 8.39 seconds
nmap Faster Execution
If you want to make faster scan, use -T4 option on nmap command.
user@user-laptop:~$ sudo nmap -A -T4 10.10.28.3
Starting Nmap 5.00 ( http://nmap.org ) at 2010-08-30 17:38 WIT
Interesting ports on 10.10.28.3:
Not shown: 998 closed ports
PORT STATE SERVICE VERSION
5009/tcp open airport-admin Apple AirPort admin
10000/tcp open snet-sensor-mgmt?
MAC Address: 00:1F:F3:42:BD:75 (Apple)
Device type: general purpose
Running: NetBSD 4.X
OS details: NetBSD 4.99.4
Network Distance: 1 hop
OS and Service detection performed. Please report any incorrect results at http://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 83.68 seconds