Encryption

*Bermaksud- menukar bahasa yang boleh difahami kepada x boleh difahami dgn mnggunakan chipher @ key.
plaintext-bahasa asal (bahasa yang difahami)
chipher text-bahasa kod (bahasa yang x boleh difahami)

*encryption algorithm-PGP (prety good privacy), ceaser chipher, MDS HASH, 3DES/DES.

*Have 2 type of encryption - symmetric n asymmetric encryption.

Differences view	Symmetric encryption	Asymmetric encryption
Meaning	Guna key yg sama	Guna 2 key yg berbeza (private n public)
Function	M’bolehkan ketepatan comm. Antara 2 pihak dalam p’sekitaran t’tutup	M’aktifkan k’selamatan dgn tepat pada symmetric encryption yg x b’fungsi@susah utk d’implementasi
Computer efficiency	Kelajuan yg luar biasa sejak operasi relative yg mudah digunakan telah dilaksanakan dengan cekap	M’hitung dgn p’lahan2 dgn m’gunakan perisian yg berat n operasi yg komplek b’dasarkan encryption utk menyelesaikan masalah teori nombor.
Key size	M’gunakan 128-bit kunci simetri yg dianggap sangat selamat	Paling kurang Guna 1000-bits saiz kunci untuk m’capai tahap yg m’cukupi dan tahap keselamatan t’kini.
Hardware	Melakukan algorithm yg seserhana n memerlukan hardware yg murah	Melakukan algorithm yg komplek n memerlukan hardware yg powerful
security	-b’dasarkan pd kekuatan algorithm n saiz kunci -ketepatan saiz kunci b’gantung pd kaedah encryption	Sama dengan symmetric

ROJAK

Arp- (Address Resolution Protocol)
      - Provide IP to internet Address
Nbstat- Display TCP/IP connection using netbios
          - Provide that that computer IP address
Netstat- Provide the connection both the local and remote, ports and the state of the connection.
IP segment- untuk mengelakkan delay dalam kelas
                 e.g: 192.168.100.248 (semua IP dari 1-248 akan di scan walaupun IP yang diguna hanya 5)

Linux as server

open command line - ctrl+alt+F1
close command line - ctrl+alt+F7
ls                           - paparkan flder in command line
mkdir                    - buat folder
cd "nama file"        - masuk subfolder
cd                        - balik ke menu awal
cat >                    - buat file
cat                       - nak cek file yg dah dibuat
mv                      - tukarnama file @ nak pindah file ke folder lain
                           e.g:  mv /root/raja/setup.txt /root/USR/opensource/setup.bak
vi                        - buat file baru
:wq                     - save file
i                          - insert data dalam file
/sbin                    - kalau dalam open terminal kene tambah ni kat depan
q                         - back to localhost kalau salah command
ctrl+c                  - back to localhost












                                                   
          

CHANGE USER ACCAUNT

su
[root@localhost ~]# ls
anaconda-ks.cfg  install.log  install.log.syslog
[root@localhost ~]# clear

[root@localhost ~]# useradd RAJA
bash: useradd: command not found
[root@localhost ~]# useradd RAJA
bash: useradd: command not found
[root@localhost ~]# /sbin useradd raja
bash: /sbin: is a directory
[root@localhost ~]# ls
anaconda-ks.cfg  install.log  install.log.syslog
[root@localhost ~]# adduser RAJA
bash: adduser: command not found
[root@localhost ~]# useradd RAJA
bash: useradd: command not found
[root@localhost ~]# cat /etc/shadow
root:$1$lYyi1Dmv$300DIzdNcqFmbulL77ruR1:14983:0:99999:7:::
bin:*:14983:0:99999:7:::
daemon:*:14983:0:99999:7:::
adm:*:14983:0:99999:7:::
lp:*:14983:0:99999:7:::
sync:*:14983:0:99999:7:::
shutdown:*:14983:0:99999:7:::
halt:*:14983:0:99999:7:::
mail:*:14983:0:99999:7:::
news:*:14983:0:99999:7:::
uucp:*:14983:0:99999:7:::
operator:*:14983:0:99999:7:::
games:*:14983:0:99999:7:::
gopher:*:14983:0:99999:7:::
ftp:*:14983:0:99999:7:::
nobody:*:14983:0:99999:7:::
nscd:!!:14983:0:99999:7:::
vcsa:!!:14983:0:99999:7:::
rpc:!!:14983:0:99999:7:::
mailnull:!!:14983:0:99999:7:::
smmsp:!!:14983:0:99999:7:::
apache:!!:14983:0:99999:7:::
pcap:!!:14983:0:99999:7:::
ntp:!!:14983:0:99999:7:::
dbus:!!:14983:0:99999:7:::
avahi:!!:14983:0:99999:7:::
hsqldb:!!:14983:0:99999:7:::
rpcuser:!!:14983:0:99999:7:::
nfsnobody:!!:14983:0:99999:7:::
sshd:!!:14983:0:99999:7:::
haldaemon:!!:14983:0:99999:7:::
avahi-autoipd:!!:14983:0:99999:7:::
xfs:!!:14983:0:99999:7:::
gdm:!!:14983:0:99999:7:::
kismec11:$1$lGCwEVAe$WgtfqjHHnI1W09AKsK5fv1:14983:0:99999:7:::
RAJA:!!:14983:0:99999:7:::
ali:!!:14983:0:99999:7:::
KING:!!:14983:0:99999:7:::
[root@localhost ~]# cat /etc/passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
news:x:9:13:news:/etc/news:
uucp:x:10:14:uucp:/var/spool/uucp:/sbin/nologin
operator:x:11:0:operator:/root:/sbin/nologin
games:x:12:100:games:/usr/games:/sbin/nologin
gopher:x:13:30:gopher:/var/gopher:/sbin/nologin
ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
nobody:x:99:99:Nobody:/:/sbin/nologin
nscd:x:28:28:NSCD Daemon:/:/sbin/nologin
vcsa:x:69:69:virtual console memory owner:/dev:/sbin/nologin
rpc:x:32:32:Portmapper RPC user:/:/sbin/nologin
mailnull:x:47:47::/var/spool/mqueue:/sbin/nologin
smmsp:x:51:51::/var/spool/mqueue:/sbin/nologin
apache:x:48:48:Apache:/var/www:/sbin/nologin
pcap:x:77:77::/var/arpwatch:/sbin/nologin
ntp:x:38:38::/etc/ntp:/sbin/nologin
dbus:x:81:81:System message bus:/:/sbin/nologin
avahi:x:70:70:Avahi daemon:/:/sbin/nologin
hsqldb:x:96:96::/var/lib/hsqldb:/sbin/nologin
rpcuser:x:29:29:RPC Service User:/var/lib/nfs:/sbin/nologin
nfsnobody:x:65534:65534:Anonymous NFS User:/var/lib/nfs:/sbin/nologin
sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
haldaemon:x:68:68:HAL daemon:/:/sbin/nologin
avahi-autoipd:x:100:102:avahi-autoipd:/var/lib/avahi-autoipd:/sbin/nologin
xfs:x:43:43:X Font Server:/etc/X11/fs:/sbin/nologin
gdm:x:42:42::/var/gdm:/sbin/nologin
kismec11:x:500:500:IT DEPARTMENT:/home/kismec11:/bin/bash
RAJA:x:501:501::/home/RAJA:/bin/bash
ali:x:502:502::/home/ali:/bin/bash
KING:x:503:503::/home/KING:/bin/bash
[root@localhost ~]# clear

[root@localhost ~]# su RAJA
[RAJA@localhost root]$ su root
Password:
[root@localhost ~]#

command in linux

[kismec11@localhost ~]$ su
Password:
[root@localhost kismec11]# cd
[root@localhost ~]# ls
anaconda-ks.cfg  install.log  install.log.syslog
[root@localhost ~]# mkdir dog
[root@localhost ~]# cd dog
[root@localhost dog]# ls
[root@localhost dog]# cd
[root@localhost ~]# ls
anaconda-ks.cfg  dog  install.log  install.log.syslog
[root@localhost ~]# cd dog
[root@localhost dog]# mkdir cat
[root@localhost dog]# cd cat
[root@localhost cat]# mkdir mouse
[root@localhost cat]# cd mouse
[root@localhost mouse]# cat >mickey.txt
apple.txt
oren.txt
grape.txt
ciku.txt
[root@localhost mouse]# cat mickey.txt
apple.txt
oren.txt
grape.txt
ciku.txt
[root@localhost mouse]# cat >BBQ.txt
ayam.list
nugget.list
roaster.list
[root@localhost mouse]# cat BBQ.txt
ayam.list
nugget.list
roaster.list
[root@localhost mouse]# cd
[root@localhost ~]# ls
anaconda-ks.cfg  dog  install.log  install.log.syslog
[root@localhost ~]# cd dog
[root@localhost dog]# ls
cat
[root@localhost dog]# cd cat
[root@localhost cat]# ls
mouse
[root@localhost cat]# cd mouse
[root@localhost mouse]# ls
BBQ.txt  mickey.txt
[root@localhost mouse]# cat mickey.txt
apple.txt
oren.txt
grape.txt
ciku.txt
[root@localhost mouse]# cat BBQ.txt
ayam.list
nugget.list
roaster.list
[root@localhost mouse]# ls
BBQ.txt  mickey.txt
[root@localhost mouse]# mv mickey.txt mouse.txt
[root@localhost mouse]# ls
BBQ.txt  mouse.txt
[root@localhost mouse]# cd
[root@localhost ~]# ls
anaconda-ks.cfg  dog  install.log  install.log.syslog
[root@localhost ~]# cd dog
[root@localhost dog]# ls
cat
[root@localhost dog]# cd cat
[root@localhost cat]# cat >mickey.txt
apple.txt
oren.txt
grape.txt
ciku.txt
[root@localhost cat]# ls
mickey.txt  mouse
[root@localhost cat]# cat >BBQ.txt
ayam.list
nugget.list
roaster.list
[root@localhost cat]# ls
BBQ.txt  mickey.txt  mouse
[root@localhost cat]# cd mouse
[root@localhost mouse]# ls
BBQ.txt  mouse.txt
[root@localhost mouse]# rm mouse.txt
rm: remove regular file `mouse.txt'? y
[root@localhost mouse]# ls
BBQ.txt
[root@localhost mouse]# rm BBQ.txt
rm: remove regular file `BBQ.txt'? y
[root@localhost mouse]# ls
[root@localhost mouse]# cd cat
bash: cd: cat: No such file or directory
[root@localhost mouse]# cd
[root@localhost ~]# ls
anaconda-ks.cfg  dog  install.log  install.log.syslog
[root@localhost ~]# cd dog
[root@localhost dog]# ls
cat
[root@localhost dog]# cd cat
[root@localhost cat]# ls
BBQ.txt  mickey.txt  mouse
[root@localhost cat]# cat BBQ.txt
ayam.list
nugget.list
roaster.list
[root@localhost cat]# cat mickey.txt
apple.txt
oren.txt
grape.txt
ciku.txt
[root@localhost cat]# cd mouse
[root@localhost mouse]# ls
[root@localhost mouse]# cd
[root@localhost ~]# ls
anaconda-ks.cfg  dog  install.log  install.log.syslog
[root@localhost ~]# cd dog
[root@localhost dog]# ls
cat
[root@localhost dog]# cd cat
[root@localhost cat]# ls
BBQ.txt  mickey.txt  mouse
[root@localhost cat]# cp BBQ.txt
cp: missing destination file operand after `BBQ.txt'
Try `cp --help' for more information.
[root@localhost cat]# cp BBQ.txt cat
[root@localhost cat]# ls
BBQ.txt  cat  mickey.txt  mouse
[root@localhost cat]# cd
[root@localhost ~]# ls
anaconda-ks.cfg  dog  install.log  install.log.syslog
[root@localhost ~]# cd dog
[root@localhost dog]# ls
cat
[root@localhost dog]# cd cat
[root@localhost cat]# ls
mouse  mouse.txt
[root@localhost cat]# cd mouse
[root@localhost mouse]# ls
BBQ.txt  mouse.txt
[root@localhost mouse]# cd
[root@localhost ~]# ls
anaconda-ks.cfg  dog  install.log  install.log.syslog
[root@localhost ~]# cd dog
[root@localhost dog]# ls
cat
[root@localhost dog]# cd cat
[root@localhost cat]# ls
mouse  mouse.txt
[root@localhost cat]# rm mouse.txt
rm: remove regular file `mouse.txt'? y
[root@localhost cat]# ls
mouse
[root@localhost cat]# cd mouse
[root@localhost mouse]# ls
BBQ.txt  mouse.txt
[root@localhost mouse]# cp /root/dog/cat/mouse/mouse.txt /root/dog/cat/mouse.txt
[root@localhost mouse]# ls
BBQ.txt  mouse.txt
[root@localhost mouse]#

BANDWIDTH MANAGEMENT

Mekanisme pengurusan Bandwidth boleh digunakan untuk prestasi jurutera selanjutnya dan termasuk:
- Bentuk lalu lintas (had kadar).


Publisher's Description

Bandwidth Management and Firewall will allow to limit bandwidth for a computer or group of computers comunicating from/to internet or to limit bandwidth for some network service.

In this case computer or service with limited bandwidth can not exceed assigned limit. Bandwidth limitation is possible to set by header fields of protocols: Ethernet, IP, TCP, UDP, ICMP.

DoS attack protection secures against SYN flood or connect flood attack and TCP protocol inspection drops harmful TCP packets. In firewall can be set prohibiting of opening TCP connection from chosen side. These functions can protect corporate network connected to internet and secures chosen opened ports on gateway used for connecting from internet to corporate network. Packet filter can work with protocols : Ethernet, IP v4, TCP, UDP, ICMP.

You can monitor and log bandwidth utilization for some computer or group of computers or for some network service. Bandwidth Management and Firewall has counters which allows monitoring of current data flow and sum of transferred data for some computer or network service. The results can be used for efficient using of bandwidth leased from your ISP and for detection of bandwidth lack.

TCP/IP UTILITIES

1.) ARP       - Address Resolution Protocol.
                    - Provides IP to Ethernet addresses.-Menyediakan IP ke alamat Ethernet.
                    - Each hardware card has an address coded in.- Setiap kad mempunyai alamat kod masuk.
2.) Nbtstat    - Displays TCP/IP connections using netbios.-Mempamerkan sambungan TCP/IP menggunakan  netbios.
                    - Provide that computers IP address. - Bagi alamat IP PC.
3.) Netstat    - Provides the connection both the local and remote, ports and the state of the connection. - Menyediakan Sambungan baik tempatan dan luar, tapak dan keadaan sambungan.
4.) Ping         - Verify connection and also used quite frequently as a troubleshooting tools. - Pengesahan sambungan dan sebagai penyelesaian masalah
5.) Route      - allows you to view and manipulate the routing tables. - membolehkan anda untuk melihat dan memanipulasi jadual routing.
                    - Useful tool Diagnosing and modifying networking routing issues.
6.) Tracert    - allows you to see the route taken by packages from yourself to a destination.
                    - Also show the time it takes.
                    - Also be used to determined the IP address of a service were you only know the name.
7.) Winipcfg - It will tell you your present IP address and your subnet mask.
                    - If you click "more info" it will also provide the DNS and WINS servers if   you have any.