라우터 인터페이스 확인
show ip interface brief

케이블 확인(DTE / DCE)
show controllers serial1/0

라우터 설정 (+telnet)

[R1]
config t
hostname HACKER
interface fastethernet0/0
ip address 100.100.100.254 255.255.255.0
no shutdown
exit
interface serial1/0
ip address 1.1.1.1 255.255.255.252
no shutdown
exit
router rip
version 2
network 100.100.100.0
network 1.1.1.0
line vty 0 4
transport input telnet
password 123456
exit
exit

[R2]
config t
hostname ST
interface fastethernet0/0
ip address 125.246.95.254 255.255.255.0
no shutdown
exit
interface serial1/0
케이블이 DCE라면 - clock rate 64000
ip address 1.1.1.2 255.255.255.252
no shutdown
exit
router rip
version 2
network 125.246.95.0
network 1.1.1.0
line vty 0 4
transport input telnet
password 123456
exit
exit