CCNA 14강 수업내용

@@OSPF(Open Shortest Path First)
-알고리즘 : Link State 계열에 SPF(Shortest Path First) 알고리즘 사용

-정보수집 : OSPF PDU 
No Type                                 
 1   Hello : Multicast(224.0.0.5)로 Hello Packet을 전달 Neighbor확인
 2   DBD(Database Descrption) : 인접관계를 맺는데 사용
 3   LSR(Link State Request) : 상세한 정보 요청시 사용
 4   LSU(Link State Update) : LSAs 실어 나를때 사용
 5   LSA(Link State Ack) : DBD,LSR,LSU에 응답 

-BestPath : 누적 Cost
Cost = 10^8(100000000) / Bandwidth(bps)
100mbps = 100000000  / 100000000 = 1
2048kbps = 100000000 / 2048000 = 48
loopback = 1

-Network 유지 : Neighbor의 Hello Packet
                       Update : 10초, Holdtime : 40초

-관리거리 : 110

@OSPF 설정방법
Router(config)#router ospf <process ID> => OSPF Enable
Router(config-router)#router-id<Router ID> => Router-ID 수동설정
Router(config-router)#no auto-summary => Default Enable
Router(config-router)#network <Classless><Wildcardmask><Area ID>

@OSPF Config
R1#sh ip route connect

R2#sh ip route connect

R3#sh ip route connect

[Capture 하기]
Dynagen => capture R1 s1/0 OSPF.cap HDLC

R1
en
conf t
router ospf 1
router-id 1.1.1.1
network 172.11.0.0 0.0.0.255 area 0
network 172.11.1.0 0.0.0.255 area 0
network 192.168.1.0 0.0.0.3 area 0
network 192.168.1.8 0.0.0.3 area 0
end

R2
en
conf t
router ospf 1
network 172.12.0.0 0.0.0.255 area 0
network 172.12.1.0 0.0.0.255 area 0
network 192.168.1.0 0.0.0.3 area 0
network 192.168.1.4 0.0.0.3 area 0
end

R3
en
conf t
router ospf 2
router-id 3.3.3.3
network 172.13.0.0 0.0.0.255 area 0
network 172.13.1.0 0.0.0.255 area 0
network 192.168.1.4 0.0.0.3 area 0
network 192.168.1.8 0.0.0.3 area 0
end

@OSPF 상태
init
2way
exstart
exchange
loading
full
 
                           Down
A(1.1.1.1) <---------------------> B(2.2.2.2)
                        init상태
Hello  -------------------------->
                      2way상태
         <-------------------------  Hello
                     Exstart상태
Slave                                           Master
                   Exchange상태
          <------------------------- DBD
 DBD   -------------------------->
          <-------- LSAck --------->

          <------------------------- LSR
LSU(LSAs) ---------------------->
LSR    --------------------------->
          <-------------------------- LSU(LSAs)
          <------- LSAck ----------->
                    Loading 상태
                        Full 상태

@Debug Message를 통해 OSPF 상태 확인
R1#debug ip ospf events
R1#clear ip ospf process
Reset ALL OSPF Processes [no] : yes
R1# un all

@OSPF Interface 상태확인 및 변경
R2#sh ip ospf interface
Serial1/1 is up, line protocol is up
  Internet Address 192.168.1.5/30, Area 0
  Process ID 1, Router ID 172.12.1.1, Network Type POINT_TO_POINT, Cost: 48

Loopback1 is up, line protocol is up
  Internet Address 172.12.1.1/24, Area 0
  Process ID 1, Router ID 172.12.1.1, Network Type LOOPBACK, Cost: 1

FastEthernet0/0 is up, line protocol is up
  Internet Address 172.12.0.1/24, Area 0
  Process ID 1, Router ID 172.12.1.1, Network Type BROADCAST, Cost: 1

R1
conf t
int lo 0
ip ospf network point-to-point
int lo 1
ip ospf network point-to-point
end

R2
conf t
int lo 1
ip ospf network point-to-point
end

R3
conf t
int lo 0
ip ospf network point-to-point
int lo 1
ip ospf network point-to-point
end