이더넷(Ethernet) 인터페이스(Interface) 란?

Ethernet Interface

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LAN구간을 연결하는 Interface이며 IEEE에서 지정한 표준 Protocol이기 때문에
통신방법 , 전송속도 , 대역 폭등이 표준으로 규정되어 있기 때문에
연결을 실시하게 되면 Layer 2까지는 기본적으로 통신이 실시된다.


                          192.168.12.0/24                          192.168.23.0/24
                  S1/0                              S1/1    S1/0                              S1/1
              R1-------------------------------R2-------------------------------R3
               |                                             |                                            |
            Fa0/0                                        Fa0/0                                     Fa0/0
               |                                             |                                            |
             SW1                                        SW2                                        SW3
       192.168.1.0/24                            192.168.2.0/24                           192.168.3.0/24


1. R1
Router# conf t
!
Router(config)# hostname R1
!
R1(config)# interface fastethernet 0/0
R1(config-if)# no shutdown    : Layer 1 활성화 상태로 전환
R1(config-if)# ip address 192.168.1.254 255.255.255.0  : Layer 3 주소 할당 (Layer 2는 표준이므로 설정 생략)

* 정보 확인

R1# show ip route : Routing Table 확인
C    192.168.1.0/24 is directly connected, FastEthernet0/0

R1# ping 192.168.1.1    : PC  <-----  G/W
R1# ping 192.168.1.2    : PC  <-----  G/W
R1# ping 192.168.1.3    : PC  <-----  G/W
PC> ping 192.168.1.254 : PC  ----->  G/W

R1# show arp : ARP Table 확인
Protocol  Address          Age (min)  Hardware Addr     Type   Interface
Internet  192.168.1.1                 1   000A.F326.2AD5   ARPA   FastEthernet0/0
Internet  192.168.1.2                 0   00D0.BA4B.B3A2  ARPA   FastEthernet0/0
Internet  192.168.1.3                 0   000C.858D.7C45   ARPA   FastEthernet0/0
Internet  192.168.1.254              -   00D0.BC20.3901   ARPA   FastEthernet0/0


R1# show interface fastethernet 0/0
FastEthernet0/0 is up, line protocol is up (connected)
  Hardware is Lance, address is 00d0.bc20.3901 (bia 00d0.bc20.3901)
  Internet address is 192.168.1.254/24
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255



2. R2
Router# conf t
!
Router(config)# hostname R2
!
R2(config)# interface fastethernet 0/0
R2(config-if)# no shutdown 
R2(config-if)# ip address 192.168.2.254 255.255.255.0

* 정보 확인

R2# show ip route
R2# show arp
R2# show interface fastethernet 0/0
R2# show running-config
R2# ping 192.168.2.1  : PC3통신
R2# ping 192.168.2.2  : PC4통신



3. R3
Router# conf t
!
Router(config)# hostname R3
!
R2(config)# interface fastethernet 0/0
R2(config-if)# no shutdown 
R2(config-if)# ip address 192.168.3.254 255.255.255.0

* 정보 확인

R3# show ip route
R3# show arp
R3# show interface fastethernet 0/0
R3# show running-config
R3# ping 192.168.3.1  : PC3통신
R3# ping 192.168.3.2  : PC4통신