공부

------------------ cmd ------------------------
1) ping -n 1 8.8.8.8
   [ping -n x(x번을 의미한다.)]
 1-1) ping 8.8.8.8
      -> 기본적으로 4번 실행한다.
 1-2) ping -l 1400 -n 1 8.8.8.8
 1-3) ping -f -l 2000 -n 1 8.8.8.8
      (-f는 Do Not Fragment)

2) arp -a
   arp -d 

3) netstat -r
4) ipconfig /all

L4: port address
   ->http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml
port: 16bit -> 0~ 65535

A - 0
  - 1
    ...
  -65535
[ Port == Service ]

System Port(Well Known Port)
 :web은 80 예를들어 www.naver.com:80
User Port(Registered Port)
 :사용자 등록 Port
Dynamic/Private
 :누구든지 사용할 수 있다.
http:80
smtp:25

 

192.168.0.0
(2^n = 2, n=1)
NNNNNNNN-NNNNNNNN-NNNNNNNN-HHHHHHHH

NNNNNNNN-NNNNNNNN-NNNNNNNN-NHHHHHHH
[1]: NNNNNNNN-NNNNNNNN-NNNNNNNN-0HHHHHHH
 (1)Range:NNNNNNNN-NNNNNNNN-NNNNNNNN-00000000 NNNNNNNN-NNNNNNNN-NNNNNNNN-01111111
  192.168.0.0 ~ 192.168.0.127
 (2)192.168.0.0
 (3)192.168.0.127
 (4)192.168.0.1 ~ 192.168.0.126

 comp1:192.168.0.1
 comp2:192.168.0.2
 comp3:192.168.0.3
 gateway:192.168.0.126
[2] NNNNNNNN-NNNNNNNN-NNNNNNNN-1HHHHHHH
(2^n = 2, n=1)
 NNNNNNNN-NNNNNNNN-NNNNNNNN-1NHHHHHH
 NNNNNNNN-NNNNNNNN-NNNNNNNN-10HHHHHH
 (1)Range:NNNNNNNN-NNNNNNNN-NNNNNNNN-10000000 NNNNNNNN-NNNNNNNN-NNNNNNNN-10111111
  192.168.0.128 ~ 192.168.0.191
 (2)192.168.0.128
 (3)192.168.0.191
 (4)192.168.0.129 ~ 192.168.0.190

 comp4:192.168.0.129
 comp5:192.168.0.130
 comp6:192.168.0.131
 gateway:192.168.0.190
   
 NNNNNNNN-NNNNNNNN-NNNNNNNN-11HHHHHH
 (1)Range:NNNNNNNN-NNNNNNNN-NNNNNNNN-11000000 NNNNNNNN-NNNNNNNN-NNNNNNNN-11111111
  192.168.0.192 ~ 192.168.0.255
 (2)192.168.0.192
 (3)192.168.0.255
 (4)192.168.0.193 ~ 192.168.0.254

 comp7:192.168.0.193
 comp8:192.168.0.194
 comp9:192.168.0.195
 gateway:192.168.0.254

192.168.1.0
 NNNNNNNN-NNNNNNNN-NNNNNNNN-HHHHHHHH
 (1)Range: 192.168.1.0 ~ 192.168.1.255
 (2)192.168.1.0
 (3)192.168.1.255
 (4)192.168.1.1 ~ 192.168.1.254
 
 comp10:192.168.1.2
 comp11:192.168.1.3
 comp12:192.168.1.4
 gateway:192.168.1.254