CCNP-5 OSPF试验1
试验拓扑：
试验要求：模拟在广播环境下，
OSPF
的配置与调试。
试验目的：掌握
OSPF
的基本配置，并且能够分析得到
OSPF
在广播环境下邻居发现过程，
DR/BDR
选举过程，定时器的时间间隔。
实验配置：
R1
：
R1(config)#int f0/0
R1(config-if)#ip add 199.99.1.1 255.255.255.0
R1(config-if)#no shu
R1(config-if)#exit
R1(config)#int loop0
R1(config-if)#ip add
1.1.1
.1 255.255.255.0
R1(config-if)#ip ospf network point-to-point
R1(config-if)#exit
R1(config)#router ospf 100
R1(config-router)#router-id
1.1.1
.1
R1(config-router)#network 199.99.1.0
0.0.0
.255 a 0
R2
：
R2(config)#int f0/0
R2(config-if)#ip add 199.99.1.2 255.255.255.0
R2(config-if)#no shu
R2(config-if)#exit
R2(config)#int loop0
R2(config-if)#ip add
2.2.2
.2 255.255.255.0
R2(config-if)#ip ospf network point-to-point
R2(config-if)#exit
R2(config)#router ospf 100
R2(config-router)#router-id
2.2.2
.2
R2(config-router)#network 199.99.1.0
0.0.0
.255 a 0
R3
：
R3(config)#int f0/0
R3(config-if)#ip add 199.99.1.3 255.255.255.0
R3(config-if)#no shu
R3(config-if)#exit
R3(config)#int loop0
R3(config-if)#ip add
3.3.3
.3 255.255.255.0
R3(config-if)#ip ospf network point-to-point
R3(config-if)#exit
R3(config)#router ospf 100
R3(config-router)#router-id
3.3.3
.3
R3(config-router)#network 199.99.1.0
0.0.0
.255 area 0
配置完成后，使用
show ip ospf interface
命令查看端口类型：
R1#show ip ospf interface f0/0
FastEthernet0/0 is up, line protocol is up
Internet Address 199.99.1.1/24, Area 0
Process ID 100, Router ID
1.1.1
.1, Network Type BROADCAST, Cost: 1
Transmit Delay is 1 sec, State DROTHER, Priority 1
Designated Router (ID)
3.3.3
.3, Interface address 199.99.1.3
Backup Designated router (ID)
2.2.2
.2, Interface address 199.99.1.2
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Hello due in 00:00:01
Supports Link-local Signaling (LLS)
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 2, Adjacent neighbor count is 2
Adjacent with neighbor
2.2.2
.2 (Backup Designated Router)
Adjacent with neighbor
3.3.3
.3 (Designated Router)
Suppress hello for 0 neighbor(s)
R2#show ip ospf interface f0/0
FastEthernet0/0 is up, line protocol is up
Internet Address 199.99.1.2/24, Area 0
Process ID 100, Router ID
2.2.2
.2, Network Type BROADCAST, Cost: 1
Transmit Delay is 1 sec, State BDR, Priority 1
Designated Router (ID)
3.3.3
.3, Interface address 199.99.1.3
Backup Designated router (ID)
2.2.2
.2, Interface address 199.99.1.2
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Hello due in 00:00:06
Supports Link-local Signaling (LLS)
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 0, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 2, Adjacent neighbor count is 2
Adjacent with neighbor
1.1.1
.1
Adjacent with neighbor
3.3.3
.3 (Designated Router)
Suppress hello for 0 neighbor(s)
R3#show ip ospf interface f0/0
FastEthernet0/0 is up, line protocol is up
Internet Address 199.99.1.3/24, Area 0
Process ID 100, Router ID
3.3.3
.3, Network Type BROADCAST, Cost: 1
Transmit Delay is 1 sec,
State DR
, Priority 1
Designated Router (ID)
3.3.3
.3, Interface address 199.99.1.3
Backup Designated router (ID)
2.2.2
.2, Interface address 199.99.1.2
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Hello due in 00:00:07
Supports Link-local Signaling (LLS)
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 2, Adjacent neighbor count is 2
Adjacent with neighbor
1.1.1
.1
Adjacent with neighbor
2.2.2
.2 (Backup Designated Router)
Suppress hello for 0 neighbor(s)
不仅可以看到网络类型是
BROADCAST
，还可以知道端口属于哪个
AREA
，
ROUTER ID
是多少，优先级都是默认值
1DR,BDR
是谁，
HELLO/DEAD/WAIT
计时器为多少等等。
使用
show ip ospf neiighbore
命令查看
OSPF
邻居表：
R1#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
R2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
R3#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
通过上面的输出可以知道
R3
是
DR
，
R2
是
BDR
，
R1
为
DROther
，这是因为
R3
的
router-id
最大，
R2
的次之，
R1
最小。再使用
show ip ospf database
查看都有哪些
LSA
类型：
R1#show ip ospf database
OSPF Router with ID (
1.1.1
.1) (Process ID 100)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
199.99.1.3
3.3.3
.3 354 0x80000001 0x
00736F
R2#show ip ospf database
OSPF Router with ID (
2.2.2
.2) (Process ID 100)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
199.99.1.3
3.3.3
.3 371 0x80000001 0x
00736F
R3#show ip ospf database
OSPF Router with ID (
3.3.3
.3) (Process ID 100)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
199.99.1.3
3.3.3
.3 378 0x80000001 0x
00736F
可以看到只有
1
类和
2
类
LSA
。
然后我们抓取一下
R1
的
debug
信息看看：
R1#debug ip ospf adj
OSPF adjacency events debugging is on
R1#
R1#clear ip ospf p
R1#clear ip ospf process
Reset ALL OSPF processes? [no]: y
R1#
*Mar 1 00:13:57.483: OSPF: Interface FastEthernet0/0 going Down
*Mar 1 00:13:57.483: OSPF:
1.1.1
.1 address 199.99.1.1 on FastEthernet0/0 is dead, state DOWN
*Mar 1 00:13:57.483: OSPF: Neighbor change Event on interface FastEthernet0/0
*Mar 1 00:13:57.483: OSPF: DR/BDR election on FastEthernet0/0
*Mar 1 00:13:57.487: OSPF: Elect BDR
2.2.2
.2
*Mar 1 00:13:57.487: OSPF: Elect DR
3.3.3
.3
*Mar 1 00:13:57.487: DR:
3.3.3
.3 (Id) BDR: 2.2.2.2 (Id)
*Mar 1 00:13:57.487: OSPF:
2.2.2
.2 address 199.99.1.2 on FastEthernet0/0 is dead, state DOWN
*Mar 1 00:13:57.487: %OSPF-5-ADJCHG: Process 100, Nbr
2.2.2
.2 on FastEthernet0/0 from FULL to DOWN, Neighbor Down: Interface down or detached
*Mar 1 00:13:57.491: OSPF: Neighbor change Event on interface FastEthernet0/0
*Mar 1 00:13:57.491: OSPF: DR/BDR election on FastEthernet0/0
*Mar 1 00:13:57.491: OSPF: Elect BDR
0.0.0
.0
*Mar 1 00:13:57.491: OSPF: Elect DR
3.3.3
.3
*Mar 1 00:13:57.495: DR:
3.3.3
.3 (Id) BDR: none
*Mar 1 00:13:57.495: OSPF:
3.3.3
.3 address 199.99.1.3 on FastEthernet0/0 is dead, state DOWN
*Mar 1 00:13:57.495: %OSPF-5-ADJCHG: Process 100, Nbr
3.3.3
.3 on FastEthernet0/0 from FULL to DOWN, Neighbor Down: Interface down or detached
*Mar 1 00:13:57.499: OSPF: Neighbor change Event on interface FastEthernet0/0
*Mar 1 00:13:57.499: OSPF: DR/BDR election on FastEthernet0/0
*Mar 1 00:13:57.499: OSPF: Elect BDR
0.0.0
.0
*Mar 1 00:13:57.499: OSPF: Elect DR
0.0.0
.0
*Mar 1 00:13:57.499: DR: none BDR: none
*Mar 1 00:13:57.503: OSPF: Remember old DR
3.3.3
.3 (id)
*Mar 1 00:13:57.587: OSPF: Interface FastEthernet0/0 going Up
*Mar 1 00:13:57.639: OSPF: 2 Way Communication to
2.2.2
.2 on FastEthernet0/0, state 2WAY
\\与R2
建立邻居关系，形成
2 Way
。
*Mar 1 00:13:57.639: OSPF: Backup seen Event before WAIT timer on FastEthernet0/0
*Mar 1 00:13:57.639: OSPF: DR/BDR election on FastEthernet0/0 \\与R2比较，选取DR/BDR
*Mar 1 00:13:57.643: OSPF: Elect BDR
2.2.2
.2
*Mar 1 00:13:57.643: OSPF: Elect DR
2.2.2
.2
*Mar 1 00:13:57.643: DR:
2.2.2
.2 (Id) BDR: 2.2.2.2 (Id)
*Mar 1 00:13:57.643: OSPF: Send DBD to
2.2.2
.2 on FastEthernet0/0 seq 0x1522 opt 0x52 flag 0x7 len 32
\\
发送数据库描述报文
*Mar 1 00:13:57.663: OSPF: 2 Way Communication to
3.3.3
.3 on FastEthernet0/0, state 2WAY
\\与R3
建立邻居关系，形成
2 Way
。
*Mar 1 00:13:57.663: OSPF: Neighbor change Event on interface FastEthernet0/0
*Mar 1 00:13:57.663: OSPF: DR/BDR election on FastEthernet0/0 \\与R2和R3比较，选取DR/BDR
*Mar 1 00:13:57.667: OSPF: Elect BDR
2.2.2
.2
*Mar 1 00:13:57.667: OSPF: Elect DR
3.3.3
.3
*Mar 1 00:13:57.667: OSPF: Send DBD to
3.3.3
.3 on FastEthernet0/0 seq 0x18AD opt 0x52 flag 0x7 len 32
\\
发送数据库描述报文给
DR
*Mar 1 00:13:57.671: OSPF: Remember old DR
2.2.2
.2 (id)
*Mar 1 00:13:57.671: OSPF: Neighbor change Event on interface FastEthernet0/0
*Mar 1 00:13:57.671: OSPF: DR/BDR election on FastEthernet0/0
*Mar 1 00:13:57.671: OSPF: Elect BDR
2.2.2
.2
*Mar 1 00:13:57.671: OSPF: Elect DR
3.3.3
.3
*Mar 1 00:13:57.675: DR:
3.3.3
.3 (Id) BDR: 2.2.2.2 (Id)
*Mar 1 00:13:57.711: OSPF: Rcv DBD from
2.2.2
.2 on FastEthernet0/0 seq 0x11D0 opt 0x52 flag 0x7 len 32 mtu 1500 state EXSTART
\\收到R2
的数据库描述报文，转到
EXSTART
状态
*Mar 1 00:13:57.711: OSPF: NBR Negotiation Done. We are the SLAVE
\\MASTER/SLAVE
的选取，在此为
R2
为
MASTER
，
R1
为
SLAVE
。
*Mar 1 00:13:57.715: OSPF: Send DBD to
2.2.2
.2 on FastEthernet0/0 seq 0x11D0 opt 0x52 flag 0x0 len 32
*Mar 1 00:13:57.759: OSPF: Rcv DBD from
3.3.3
.3 on FastEthernet0/0 seq 0x
78A
opt 0x52 flag 0x7 len 32 mtu 1500 state EXSTART
\\收到R3
的数据库描述报文，转到
EXSTART
状态
*Mar 1 00:13:57.763: OSPF: NBR Negotiation Done. We are the SLAVE
\\MASTER/SLAVE
的选取，在此为
R3
为
MASTER
，
R1
为
SLAVE
。
*Mar 1 00:13:57.763: OSPF: Send DBD to
3.3.3
.3 on FastEthernet0/0 seq 0x
78A
opt 0x52 flag 0x0 len 32
*Mar 1 00:13:57.767: OSPF: Rcv DBD from
2.2.2
.2 on FastEthernet0/0 seq 0x11D1 opt 0x52 flag 0x3 len 92 mtu 1500 state EXCHANGE
\\
交换
DBD
报文，状态转为
EXCHANGE
。
*Mar 1 00:13:57.771: OSPF: Send DBD to
2.2.2
.2 on FastEthernet0/0 seq 0x11D1 opt 0x52 flag 0x0 len 32
*Mar 1 00:13:57.879: OSPF: Rcv DBD from
2.2.2
.2 on FastEthernet0/0 seq 0x11D2 opt 0x52 flag 0x1 len 32 mtu 1500 state EXCHANGE
*Mar 1 00:13:57.879: OSPF: Exchange Done with
2.2.2
.2 on FastEthernet0/0
*Mar 1 00:13:57.883: OSPF: Send LS REQ to
2.2.2
.2 length 36 LSA count 3
\\
发送
LSR
*Mar 1 00:13:57.883: OSPF: Send DBD to
2.2.2
.2 on FastEthernet0/0 seq 0x11D2 opt 0x52 flag 0x0 len 32
*Mar 1 00:13:57.955: OSPF: Rcv DBD from
3.3.3
.3 on FastEthernet0/0 seq 0x78B opt 0x52 flag 0x3 len 92 mtu 1500 state EXCHANGE
\\
交换
DBD
报文，状态转为
EXCHANGE
。
*Mar 1 00:13:57.955: OSPF: Send DBD to
3.3.3
.3 on FastEthernet0/0 seq 0x78B opt 0x52 flag 0x0 len 32
*Mar 1 00:13:57.987: OSPF: Reset old DR on FastEthernet0/0
*Mar 1 00:13:57.987: OSPF: Build router LSA for area 0, router ID
1.1.1
.1, seq 0x80000001
*Mar 1 00:13:57.995: OSPF: Rcv LS UPD from
2.2.2
.2 on FastEthernet0/0 length 136 LSA count 3
\\
收到
LSU
*Mar 1 00:13:57.995: OSPF: Synchronized with
2.2.2
.2 on FastEthernet0/0, state FULL
*Mar 1 00:13:57.999: %OSPF-5-ADJCHG: Process 100, Nbr
2.2.2
.2 on FastEthernet0/0 from LOADING to FULL, Loading Done
\\与R2
成为
FULL
状态。
*Mar 1 00:13:57.999: OSPF: Rcv DBD from
3.3.3
.3 on FastEthernet0/0 seq 0x
78C
opt 0x52 flag 0x1 len 32 mtu 1500 state EXCHANGE
*Mar 1 00:13:57.999: OSPF: Exchange Done with
3.3.3
.3 on FastEthernet0/0
*Mar 1 00:13:58.003: OSPF: Synchronized with
3.3.3
.3 on FastEthernet0/0, state FULL *Mar 1 00:13:58.003: %OSPF-5-ADJCHG: Process 100, Nbr
3.3.3
.3 on FastEthernet0/0 from LOADING to FULL, Loading Done
\\与R3
成为
FULL
状态。
*Mar 1 00:13:58.003: OSPF: Send DBD to
3.3.3
.3 on FastEthernet0/0 seq 0x
78C
opt 0x52 flag 0x0 len 32
*Mar 1 00:13:58.083: OSPF: Rcv LS UPD from
3.3.3
.3 on FastEthernet0/0 length 60 LSA count 1
*Mar 1 00:14:02.583: OSPF: Rcv LS UPD from
2.2.2
.2 on FastEthernet0/0 length 64 LSA count 1
*Mar 1 00:14:02.783: OSPF: Rcv LS UPD from
3.3.3
.3 on FastEthernet0/0 length 64 LSA count 1
*Mar 1 00:14:02.855: OSPF: Rcv LS UPD from
2.2.2
.2 on FastEthernet0/0 length 64 LSA count 1
*Mar 1 00:14:02.859: OSPF: Rcv LS UPD from
3.3.3
.3 on FastEthernet0/0 length 64 LSA count 1
*Mar 1 00:14:03.135: OSPF: Rcv LS UPD from
3.3.3
.3 on FastEthernet0/0 length 64 LSA count 1
*Mar 1 00:14:03.499: OSPF: Build router LSA for area 0, router ID
1.1.1
.1, seq 0x80000003
*Mar 1 00:14:03.671: OSPF: Rcv LS UPD from
3.3.3
.3 on FastEthernet0/0 length 64 LSA count 1
红色标记
/
蓝色注释的部分比较重要，通过红色标记
/
蓝色注释的部分可以看到整个
OSPF
邻居建立和选取
DR/BDR
和交换
DBD
报文和
LSU/LSR/LSAck
报文，最终形成
FULL
状态的全部过程。
实验总结：通过这个简单的实验我们可以知道在广播环境下，
OSPF
的邻居关系是自动建立的，并且需要有
DR/BDR
地选取，还可以看到几个特别计时器的设置，
hello
间隔为
10
秒，死亡，等待时间为
hello
时间间隔的
4
倍
40
秒。
本文转自loveme2351CTO博客，原文链接：http://blog.51cto.com/loveme23/45808
，如需转载请自行联系原作者
