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ANTON
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2009-06-22 23:11:01, 조회 : 510, 추천 : 44 |
OSPF (Open Shortest Path First)
-Open : 표준 개방형
-Shortest Path First : 최단거리 우선
-헬로 패킷을 주고 받아 네이버및 어드제이션 네이버 관계구성
-Link-state 알고리즘
-상호 라우터간에 인접성을 맺고 네이버 관계가 성립된 이후에 라우팅 업데이트 실시
-네트워크에 변화가 있을때만 변화된 부분만 업데이트.증가된 부분만 업데이트 실시
-즉.Distance Vector 알고리즘을 보완한 알고리즘이다
-Multicast Update(224.0.0.5 , 224.0.0.6)
-인접성(Neighbor) [조건]
1.같은 Network은 같은 area에 포함
2.같은 Network은 같은 Hello,Dead 주기가 같아야함
3.인증사항 동일(Area 단위로 인증 실시)
4.Stub Tag 동일
CF-STUB
1.area x stub (e1,e2차단 o,ia만 받아들임
2.area x stub no-summary (e1,e2,ia차단 o만 받아드림 )
3.area x nssa default-information-originate (lsa 5가 광고되지않고 대신 lsa7이 광고 n1)
4.area x nssa no-summary (lsa345 광고 되지 않고 대신 lsa7이광고 n2)
n1,n2차단 area x nassa no-redistribution
---------------------------------------------------------------------------------------------------
-5가지 패킷 (Router ID를 가장 먼저 생성)
Type 1. Hello : 네이버를 찾고 네이버와의 관계유지(*는 무조건 일치)
-Area-ID *
-Hello,Dead 주기*
-인증 *
-Stub *
-Router-ID
-OSPF 우선순위값(Default = 1)
-DR/BDR 정보
-Neighbor 정보
------------------------------ 네이버 테이블 show ip ospf neighbor
Type 2. DBD (DDP):라우팅 정보를 담고 있는 데이타 베이스 정보
LSDB(Link-state Database) 생성하기 위한 첫걸음
R1------------------------------R2
LSDB = LSDB
등록 과정 : 등급별로 저장(SPF)
LSA : link-state Advertise (시퀀스 번호 일치기능) 네트워크 정보
LSR : 요청
LSU : LSR 응답으로 update packet
-----------------기본수렴-----------------------데이타베이스 테이블 show ip ospf database
Type 3.LSR
Type 4.LSU
Type 5.LSA : ACK(DBD에 대해서 수신 필요)
*DBD를 동기화 할때 사용하는 패킷은 :LSA(Link-State Advertise)
down state (Router ID 생성)
Init state *-->인접성 조건이 불일치시(업데이트가 이루어지지않음)
Two-Way state (인접성 조건이 만족됐을때)
Exstart state (M/S)
Exchange state (DBD생성 M --> S)
Loading state
Full state (모든Update가 이루어진 상태)
show ip ospf int ser0 인터페이스 상태확인
ip ospf hello-interval 헬로/데드 주기일치
----------------------------------------------------------------------------------------------------
-3가지 테이블
1.Neighbor : Show ip ospf neighbor
-Hello 페킷을 고환해서 인접성에 조건이 맞다면 네이버 관계가 성립
-자신의 기준에서 OSPF 인접성성을 맺은 네이버 라우터의 라우터 아이디가 출력
-네이버 관계가 됬는지 확인할때 사용
2.Database : Shp ip ospf database
-각각의 영역에 대한 범위를 나누어서 관리
-목적지로 가기 위한 경로들의 집합
-SPF를 이용하여 최단거리를 추적하여 최적의 경로를 라우팅 테이블에 등록
-LSDB를 동기화 하기 위해서 LSA 광고 패킷을 교환한다
-같은 Area안에서는 LSDB 내용이 같아야 한다
3.Routing : Show ip route ospf
-최적의 경로들의 집합
-라우터가 참조하는 테이블
-Metric : 10^8/링크당Bandwidth = Cost(거리비용)10^8/Bandwidth
-균등로드분산 지원(4 ~ 6)
------------------------------------------------------------------------------------------------------
-2계층 디자인 모델 (AS : 1~65551)
.같은 Network은 같은 Area안에 포함되어야한다
.모든 Area는 Area 0 을 경유해야한다
-Area단위사용: LSDB를 동기화하기 위한 LSA 광고 패킷에 대한 플러딩의 범위를 줄이기 위하여
(플러딩:내가 받은 Port를 제외하고 모든 Port로 뿌림)
-ABR Router : Area 경계 사이에서 두 Area의 LSDB를 동기화 하고 중계하는 역할
-ASBR Router: AS 경계 사이에서 외부 정보를 OSPF 전체 도메인으로 업데이트하는 라우터
-BackBone Router: Transit Area라고 불리는 Area --> Area 0
-만약 Area 0을 경유하지 못하는경우 Virtual-Link 생성
-redistribute connected subnets metric-type 1 가변
-redistribute connected subnets metric-type 2 불변
----------------------------------------------------------------------------------
-DR/BDR 선출하는 네트워크 환경 .LAN : Broadcast(자동)
.WAN : NBMA(수동 설정)
-DR/BDR 선출하지 않는 네트워크 환경 :P0int-to-point , Point to Multipoin (Sub interface)
-우선순위값(Priority 기본=1)
:OSPF에서 가장큰 우선순위값을 가진 Router가 DR로 선출
두번째로 큰 값을 가진 Router가 BDR로 선출
우선순위 값이 0일경우 = 영원히 DR/BDR이 될수없음
DR Other --> DR(224.0.0.6) DR --> DROther (224.0.0.5)
-설정:해당 interface 에서 ip ospf priority (0~255)
----------------------------------------------------------------------------------
-Router-ID 선정기준:(Router-ID가 있을경우 관리가 용이)
1.router-id 직접 설정
2.해당 Router에서 가상 Interfac가 존재할경우
가장 높은 Loopback Interface IP
3.해당 Router에서 가장 높은 IP
해당 프로세스 안에서 설정
router (As 번호)
router-id X.X.X.X
network [Local Network]
clear ip ospf process [y]
----------------------------------------------------------------------------------
LSA1:router- 기본 area정보(DR/BDR선출X) ------->Intra Area - Routing Table (0)
LSA2:network- 기본 area정보(DR/BDR선출0) ------->Intra Area - Routing Table (0)
LSA3:summary- 다른 area에서 들어온 정보(ABR) --->Inttr Area - Routing Table (0 IA)
LSA4:summary- 라우터ID(ASBR) --->Inttr Area - Routing Table (0 IA)
LSA5:AS-external- 외부 AS에서 들어온정보(ASBR) ----------->Exter Area - Routing Table (0 E1,O E2)
LSA7:AS-external- (NSSA ASBR)
----------------------------------------------------------------------------------
Summary
1.ABR Router에서실시하는 Inter route 경로정보 요약
area 1 range 10.1.0.0 255.255.0.0 (cidr사용)
------------------------------------------------------
2.ASBR Router에서 실시하는 Exter route 경로정보 요약
summary-address 172.16.8.0 255.255.248.0
----------------------------------------------------------------------------------
ospf 보안
1.네이버인증 (인터페이스만 적용)
평문 : int X
ip opsf authentication
ip opsf authentication-key XXX
MD5 : int X
ip opsf authentication message-digest
ip opsf authentication-key 1 md5 XXX
2.에어리어 인증
평문 : router ospf 1
area X authentication
int Y
ip ospf authentication-key XXX
MD5 : router ospf 1
area X authentication message-diegest
int x
ip ospf message-digest-key 1 md5 XXX
평문타입1로 인증, md5타입2로 인증 보안안할경우 0으로 인증
--------------------------------------------------------------------------------------
가상인터페이스
백본 area 떨어져 있을경우 사용
area X virtual-link 백본 area ID
가상링크인증
R1 : routr ospf 1
area 0 authentication message-digest
area 2 virtual-link 2.2.2.2 message-digest-key 1 md5 cisco
R2 : router ospf 1
area 2 virtual-link 1.1.1.1 message-digest-key 1 md5 cisco
가상 네이버인증
R1 : routr ospf 1
area 0 authentication authentication
area 2 virtual-link 2.2.2.2 authentication-key cisco
R2 : router ospf 1
area 2 virtual-link 1.1.1.1 authentication-key cisco
--------------------------------------------------------------------------------------------
대맨드 써컷
네이버 관계를 맺으면 30초마다 팻킷을 보내고
30분마다 lsa리프레스를 보낸다.(기존에 광고했던 lsa 통채로 다시 보낸 )
이런 트랙픽을 막기위해 해당 인터페이스에 ip ospf demand-circit 사용
인터페이스 타입에서 확인할수있음
r1#show run
interface Loopback0
ip address 1.1.1.1 255.255.255.0
!
interface Ethernet0/0
ip address 14.14.13.1 255.255.255.0
ip access-group 10 in
half-duplex
!
interface Serial0/0
ip address 150.14.1.1 255.255.255.0
encapsulation frame-relay
ip ospf priority 0
ip ospf demand-circuit
frame-relay map ip 150.14.1.2 103 broadcast
frame-relay map ip 150.14.1.3 103 broadcast
no frame-relay inverse-arp
frame-relay lmi-type cisco
!
interface Ethernet1/0
ip address 14.14.11.1 255.255.255.0
half-duplex
!
router ospf 1
router-id 1.1.1.1
log-adjacency-changes
area 1 authentication message-digest
area 1 virtual-link 1.1.3.3 message-digest-key 1 md5 cisco
network 1.1.1.1 0.0.0.0 area 0
network 14.14.11.1 0.0.0.0 area 1
network 14.14.13.1 0.0.0.0 area 0
network 150.14.1.1 0.0.0.0 area 0
end
r2#show run
interface Loopback0
ip address 1.1.2.2 255.255.255.0
!
interface Ethernet0/0
ip address 14.14.12.2 255.255.255.0
half-duplex
!
interface Serial0/0
ip address 150.14.1.2 255.255.255.0
encapsulation frame-relay
frame-relay map ip 150.14.1.1 203 broadcast
frame-relay map ip 150.14.1.3 203 broadcast
no frame-relay inverse-arp
!
interface Ethernet1/0
ip address 14.14.13.2 255.255.255.0
half-duplex
!
router ospf 1
router-id 1.1.2.2
log-adjacency-changes
area 2 stub
network 1.1.2.2 0.0.0.0 area 0
network 14.14.12.2 0.0.0.0 area 2
network 14.14.13.2 0.0.0.0 area 0
network 150.14.1.2 0.0.0.0 area 0
!
end
r3#show run
!
interface Loopback0
ip address 1.1.3.3 255.255.255.0
!
interface Loopback120
ip address 120.120.9.1 255.255.255.0 secondary
ip address 120.120.10.1 255.255.255.0 secondary
ip address 120.120.11.1 255.255.255.0 secondary
ip address 120.120.12.1 255.255.255.0 secondary
ip address 120.120.13.1 255.255.255.0 secondary
ip address 120.120.8.1 255.255.255.0
!
interface Ethernet0
ip address 14.14.11.3 255.255.255.0
!
interface Serial0
ip address 150.14.2.1 255.255.255.0
encapsulation frame-relay
ip ospf network broadcast
frame-relay map ip 150.14.2.3 113 broadcast
no frame-relay inverse-arp
!
router ospf 1
router-id 1.1.3.3
log-adjacency-changes
area 1 authentication message-digest
area 1 range 120.120.8.0 255.255.248.0
area 1 virtual-link 1.1.1.1 authentication-key 1 md5 cisco
redistribute connected
network 1.1.3.3 0.0.0.0 area 1
network 14.14.11.3 0.0.0.0 area 1
network 120.120.8.0 0.0.7.255 area 1
network 150.14.2.1 0.0.0.0 area 11
distribute-list prefix 10 in Serial0
!
ip prefix-list 10 seq 5 permit 128.128.1.0/24
ip prefix-list 10 seq 10 permit 128.128.2.0/24
!
1.0.0.0/8 is variably subnetted, 5 subnets, 2 masks
O 1.1.5.5/32 [110/75] via 14.14.11.1, 00:09:48, Ethernet0
O IA 1.1.4.4/32 [110/31] via 14.14.11.1, 00:09:48, Ethernet0
O 1.1.2.2/32 [110/21] via 14.14.11.1, 00:09:48, Ethernet0
O 1.1.1.1/32 [110/11] via 14.14.11.1, 00:09:48, Ethernet0
C 1.1.3.0/24 is directly connected, Loopback0
172.16.0.0/21 is subnetted, 1 subnets
O E2 172.16.8.0 [110/20] via 14.14.11.1, 00:09:48, Ethernet0
128.128.0.0/24 is subnetted, 2 subnets
O E1 128.128.1.0 [110/1064] via 150.14.2.3, 00:09:49, Serial0
O E1 128.128.2.0 [110/1064] via 150.14.2.3, 00:09:49, Serial0
10.0.0.0/24 is subnetted, 5 subnets
O E2 10.10.1.0 [110/20] via 14.14.11.1, 00:09:49, Ethernet0
O E2 10.10.2.0 [110/20] via 14.14.11.1, 00:09:49, Ethernet0
O E2 10.10.3.0 [110/20] via 14.14.11.1, 00:09:49, Ethernet0
O E2 10.10.4.0 [110/20] via 14.14.11.1, 00:09:49, Ethernet0
O E2 10.10.5.0 [110/20] via 14.14.11.1, 00:09:49, Ethernet0
14.0.0.0/24 is subnetted, 4 subnets
C 14.14.11.0 is directly connected, Ethernet0
O IA 14.14.12.0 [110/30] via 14.14.11.1, 00:09:49, Ethernet0
O 14.14.13.0 [110/20] via 14.14.11.1, 00:09:49, Ethernet0
O E2 14.14.14.0 [110/20] via 14.14.11.1, 00:09:49, Ethernet0
150.14.0.0/24 is subnetted, 2 subnets
O 150.14.1.0 [110/74] via 14.14.11.1, 00:09:49, Ethernet0
C 150.14.2.0 is directly connected, Serial0
120.0.0.0/8 is variably subnetted, 7 subnets, 2 masks
C 120.120.8.0/24 is directly connected, Loopback120
O 120.120.8.0/21 is a summary, 00:13:31, Null0
C 120.120.9.0/24 is directly connected, Loopback120
C 120.120.10.0/24 is directly connected, Loopback120
C 120.120.11.0/24 is directly connected, Loopback120
C 120.120.12.0/24 is directly connected, Loopback120
C 120.120.13.0/24 is directly connected, Loopback120
r4#show run
!
interface Loopback0
ip address 1.1.4.4 255.255.255.0
!
interface Ethernet0
ip address 14.14.12.4 255.255.255.0
!
interface Serial0
no ip address
encapsulation frame-relay IETF
shutdown
frame-relay lmi-type cisco
!
interface Serial1
no ip address
shutdown
!
router ospf 1
router-id 1.1.4.4
log-adjacency-changes
area 2 stub
network 1.1.4.4 0.0.0.0 area 2
network 14.14.12.4 0.0.0.0 area 2
!
end
bb1#show run
!
interface Loopback0
ip address 1.1.5.5 255.255.255.0
!
interface Loopback10
ip address 10.10.2.1 255.255.255.0 secondary
ip address 10.10.3.1 255.255.255.0 secondary
ip address 10.10.4.1 255.255.255.0 secondary
ip address 10.10.5.1 255.255.255.0 secondary
ip address 10.10.1.1 255.255.255.0
!
interface Loopback172
ip address 172.16.9.1 255.255.255.0 secondary
ip address 172.16.10.1 255.255.255.0 secondary
ip address 172.16.11.1 255.255.255.0 secondary
ip address 172.16.12.1 255.255.255.0 secondary
ip address 172.16.13.1 255.255.255.0 secondary
ip address 172.16.8.1 255.255.255.0
!
!
interface Ethernet0/0.11
encapsulation dot1Q 11
ip address 14.14.11.11 255.255.255.0
no snmp trap link-status
!
interface Ethernet0/0.12
encapsulation dot1Q 12
ip address 14.14.12.12 255.255.255.0
no snmp trap link-status
!
interface Serial0/0
ip address 150.14.1.3 255.255.255.0
encapsulation frame-relay
ip ospf priority 5
frame-relay map ip 150.14.1.1 301 broadcast
frame-relay map ip 150.14.1.2 302 broadcast
no frame-relay inverse-arp
frame-relay lmi-type cisco
!
interface Ethernet1/0
ip address 14.14.14.5 255.255.255.0
half-duplex
!
router ospf 1
router-id 1.1.5.5
log-adjacency-changes
summary-address 172.16.8.0 255.255.248.0
redistribute connected subnets
redistribute rip metric 1000 subnets
network 1.1.5.5 0.0.0.0 area 0
network 150.14.1.3 0.0.0.0 area 0
neighbor 150.14.1.1
neighbor 150.14.1.2
!
router rip
version 2
redistribute ospf 1 metric 5
network 10.0.0.0
network 14.0.0.0
network 172.16.0.0
no auto-summary
!
end
bb2#show run
!
interface Loopback0
ip address 1.1.6.6 255.255.255.0
!
interface Loopback128
ip address 128.128.2.1 255.255.255.0 secondary
ip address 128.128.3.1 255.255.255.0 secondary
ip address 128.128.4.1 255.255.255.0 secondary
ip address 128.128.5.1 255.255.255.0 secondary
ip address 128.128.1.1 255.255.255.0
!
interface Ethernet0
ip address 14.14.15.6 255.255.255.0
!
interface Serial0
ip address 150.14.2.3 255.255.255.0
encapsulation frame-relay
ip ospf network broadcast
ip ospf priority 0
frame-relay map ip 150.14.2.1 311 broadcast
no frame-relay inverse-arp
frame-relay lmi-type cisco
!
router eigrp 10
redistribute ospf 1 metric 1544 2000 255 1 1500 route-map AA
network 14.14.15.6 0.0.0.0
network 128.128.0.0 0.0.3.255
no auto-summary
eigrp router-id 1.1.6.6
!
router ospf 1
router-id 1.1.6.6
log-adjacency-changes
redistribute eigrp 10 metric 1000 metric-type 1 subnets
network 1.1.6.6 0.0.0.0 area 11
network 150.14.2.3 0.0.0.0 area 11
!
ip access-list standard per128
permit 128.128.1.0 0.0.0.255
permit 128.128.5.0 0.0.0.255
!
!
route-map AA permit 10
match ip address per128
!
route-map AA permit 20
!
end
bb2#show ip route
1.0.0.0/8 is variably subnetted, 6 subnets, 2 masks
O IA 1.1.5.5/32 [110/139] via 150.14.2.1, 00:03:03, Serial0
O IA 1.1.4.4/32 [110/95] via 150.14.2.1, 00:15:21, Serial0
O IA 1.1.3.3/32 [110/65] via 150.14.2.1, 00:15:21, Serial0
O IA 1.1.2.2/32 [110/85] via 150.14.2.1, 00:15:21, Serial0
O IA 1.1.1.1/32 [110/75] via 150.14.2.1, 00:15:21, Serial0
C 1.1.6.0/24 is directly connected, Loopback0
172.16.0.0/21 is subnetted, 1 subnets
O E2 172.16.8.0 [110/20] via 150.14.2.1, 00:02:58, Serial0
128.128.0.0/24 is subnetted, 5 subnets
C 128.128.1.0 is directly connected, Loopback128
C 128.128.2.0 is directly connected, Loopback128
C 128.128.3.0 is directly connected, Loopback128
C 128.128.4.0 is directly connected, Loopback128
C 128.128.5.0 is directly connected, Loopback128
10.0.0.0/24 is subnetted, 5 subnets
O E2 10.10.1.0 [110/20] via 150.14.2.1, 00:03:00, Serial0
O E2 10.10.2.0 [110/20] via 150.14.2.1, 00:03:00, Serial0
O E2 10.10.3.0 [110/20] via 150.14.2.1, 00:03:00, Serial0
O E2 10.10.4.0 [110/20] via 150.14.2.1, 00:03:00, Serial0
O E2 10.10.5.0 [110/20] via 150.14.2.1, 00:03:00, Serial0
14.0.0.0/24 is subnetted, 5 subnets
O IA 14.14.11.0 [110/74] via 150.14.2.1, 00:15:23, Serial0
O IA 14.14.12.0 [110/94] via 150.14.2.1, 00:15:23, Serial0
O IA 14.14.13.0 [110/84] via 150.14.2.1, 00:15:23, Serial0
O E2 14.14.14.0 [110/20] via 150.14.2.1, 00:03:00, Serial0
C 14.14.15.0 is directly connected, Ethernet0
150.14.0.0/24 is subnetted, 2 subnets
O IA 150.14.1.0 [110/138] via 150.14.2.1, 00:03:04, Serial0
C 150.14.2.0 is directly connected, Serial0
120.0.0.0/21 is subnetted, 1 subnets
O IA 120.120.8.0 [110/65] via 150.14.2.1, 00:06:48, Serial0
bb2#
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