CCNP-7 OSPF试验3(BSCI)

简介:

CCNP-7 OSPF试验3

试验拓扑:

试验要求: R1 R2 R3 通过 FR 相连,形成 hub and spoke 网络, R1 hub 路由器,在 R1 R2 R3 上起 OSPF
试验目的:掌握 OSPF NBMA 环境下的配置和观察 OSPF NBMA 下特征。

试验配置:
R1
interface Loopback0
 ip address 100.100.100.100 255.255.255.0
 ip ospf network point-to-point
!        
interface Loopback1
 ip address 192.168.1.1 255.255.255.0
 ip ospf network point-to-point
!
interface Serial1/0
 ip address 199.99.1.1 255.255.255.0
 encapsulation frame-relay
 serial restart-delay 0
 frame-relay map ip 199.99.1.1 301 broadcast
 frame-relay map ip 199.99.1.2 301 broadcast
 frame-relay map ip 199.99.1.3 302 broadcast
 no frame-relay inverse-arp
!
router ospf 100
 router-id 100.100.100.100
 log-adjacency-changes
 network 100.100.100.0  0.0.0 .255 area 0
 network 192.168.1.0  0.0.0 .255 area 0
 network 199.99.1.0  0.0.0 .255 area 0
 neighbor 199.99.1.2
 neighbor 199.99.1.3
 
R2
interface Loopback0
 ip address  2.2.2 .2 255.255.255.0
 ip ospf network point-to-point
!        
interface Loopback1
 ip address 192.168.2.1 255.255.255.0
 ip ospf network point-to-point
!
interface Serial1/0
 ip address 199.99.1.2 255.255.255.0
 encapsulation frame-relay
 serial restart-delay 0
 frame-relay map ip 199.99.1.1 103 broadcast
 frame-relay map ip 199.99.1.3 103 broadcast
 no frame-relay inverse-arp
!
router ospf 100
 router-id  2.2.2 .2
 log-adjacency-changes
 network  2.2.2 .0 0.0.0.255 area 0
 network 192.168.2.0  0.0.0 .255 area 0
 network 199.99.1.0  0.0.0 .255 area 0
 neighbor 199.99.1.1
 
R3
interface Loopback0
 ip address  3.3.3 .3 255.255.255.0
 ip ospf network point-to-point
!        
interface Loopback1
 ip address 192.168.3.1 255.255.255.0
 ip ospf network point-to-point
!
interface Serial1/0
 ip address 199.99.1.3 255.255.255.0
 encapsulation frame-relay
 serial restart-delay 0
 frame-relay map ip 199.99.1.1 203 broadcast
 frame-relay map ip 199.99.1.2 203 broadcast
 no frame-relay inverse-arp
!
router ospf 100
 router-id  3.3.3 .3
 log-adjacency-changes
 network  3.3.3 .0 0.0.0.255 area 0
 network 192.168.3.0  0.0.0 .255 area 0
 network 199.99.1.0  0.0.0 .255 area 0
 neighbor 199.99.1.1
 
以上为基本配置,要注意用红颜色标记的部分, 因为在 NBMA 环境下,邻居关系是不会自动建立的,所以要手动添加邻居,这样他们在建立邻居关系的时候发送的不是组播,而是单播。 然后我们用 show ip ospf interface 命令查看接口:
R1#show ip ospf interface
Loopback0 is up, line protocol is up
  Internet Address 100.100.100.100/24, Area 0
  Process ID 100, Router ID 100.100.100.100, Network Type POINT_TO_POINT, Cost: 1
  Transmit Delay is 1 sec, State POINT_TO_POINT,
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
  Supports Link-local Signaling (LLS)
  Index 3/3, flood queue length 0
  Next 0x0(0)/0x0(0)
  Last flood scan length is 0, maximum is 0
  Last flood scan time is 0 msec, maximum is 0 msec
  Neighbor Count is 0, Adjacent neighbor count is 0
  Suppress hello for 0 neighbor(s)
Loopback1 is up, line protocol is up
  Internet Address 192.168.1.1/24, Area 0
  Process ID 100, Router ID 100.100.100.100, Network Type POINT_TO_POINT, Cost: 1
  Transmit Delay is 1 sec, State POINT_TO_POINT,
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
  Supports Link-local Signaling (LLS)
  Index 2/2, flood queue length 0
  Next 0x0(0)/0x0(0)
  Last flood scan length is 0, maximum is 0
  Last flood scan time is 0 msec, maximum is 0 msec
  Neighbor Count is 0, Adjacent neighbor count is 0
  Suppress hello for 0 neighbor(s)
Serial1/0 is up, line protocol is up
  Internet Address 199.99.1.1/24, Area 0
  Process ID 100, Router ID 100.100.100.100, Network Type NON_BROADCAST, Cost: 64
  Transmit Delay is 1 sec,  State DR , Priority 1
  Designated Router (ID) 100.100.100.100, Interface address 199.99.1.1
  Backup Designated router (ID)  3.3.3 .3, Interface address 199.99.1.3
  Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5
    oob-resync timeout 120
    Hello due in 00:00:28
  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 4 msec
  Neighbor Count is 2, Adjacent neighbor count is 2
    Adjacent with neighbor  2.2.2 .2
    Adjacent with neighbor  3.3.3 .3  (Backup Designated Router)
  Suppress hello for 0 neighbor(s)
 
R2#show ip ospf interface
Loopback0 is up, line protocol is up
  Internet Address  2.2.2 .2/24, Area 0
  Process ID 100, Router ID  2.2.2 .2, Network Type POINT_TO_POINT, Cost: 1
  Transmit Delay is 1 sec, State POINT_TO_POINT,
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
  Supports Link-local Signaling (LLS)
  Index 3/3, flood queue length 0
  Next 0x0(0)/0x0(0)
  Last flood scan length is 0, maximum is 0
  Last flood scan time is 0 msec, maximum is 0 msec
  Neighbor Count is 0, Adjacent neighbor count is 0
  Suppress hello for 0 neighbor(s)
Loopback1 is up, line protocol is up
  Internet Address 192.168.2.1/24, Area 0
  Process ID 100, Router ID  2.2.2 .2, Network Type POINT_TO_POINT, Cost: 1
  Transmit Delay is 1 sec, State POINT_TO_POINT,
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
  Supports Link-local Signaling (LLS)
  Index 2/2, flood queue length 0
  Next 0x0(0)/0x0(0)
  Last flood scan length is 0, maximum is 0
  Last flood scan time is 0 msec, maximum is 0 msec
  Neighbor Count is 0, Adjacent neighbor count is 0
  Suppress hello for 0 neighbor(s)
Serial1/0 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 NON_BROADCAST, Cost: 64
  Transmit Delay is 1 sec, State BDR, Priority 1
  Designated Router (ID) 100.100.100.100, Interface address 199.99.1.1
  Backup Designated router (ID)  2.2.2 .2, Interface address 199.99.1.2
  Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5
    oob-resync timeout 120
    Hello due in 00:00:03
  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 1, Adjacent neighbor count is 1
    Adjacent with neighbor 100.100.100.100  (Designated Router)
  Suppress hello for 0 neighbor(s)
 
R3#show ip ospf interface
Loopback0 is up, line protocol is up
  Internet Address  3.3.3 .3/24, Area 0
  Process ID 100, Router ID  3.3.3 .3, Network Type POINT_TO_POINT, Cost: 1
  Transmit Delay is 1 sec, State POINT_TO_POINT,
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
  Supports Link-local Signaling (LLS)
  Index 3/3, flood queue length 0
  Next 0x0(0)/0x0(0)
  Last flood scan length is 0, maximum is 0
  Last flood scan time is 0 msec, maximum is 0 msec
  Neighbor Count is 0, Adjacent neighbor count is 0
  Suppress hello for 0 neighbor(s)
Loopback1 is up, line protocol is up
  Internet Address 192.168.3.1/24, Area 0
  Process ID 100, Router ID  3.3.3 .3, Network Type POINT_TO_POINT, Cost: 1
  Transmit Delay is 1 sec, State POINT_TO_POINT,
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
  Supports Link-local Signaling (LLS)
  Index 2/2, flood queue length 0
  Next 0x0(0)/0x0(0)
  Last flood scan length is 0, maximum is 0
  Last flood scan time is 0 msec, maximum is 0 msec
  Neighbor Count is 0, Adjacent neighbor count is 0
  Suppress hello for 0 neighbor(s)
Serial1/0 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 NON_BROADCAST, Cost: 64
  Transmit Delay is 1 sec, State BDR, Priority 1
  Designated Router (ID) 100.100.100.100, Interface address 199.99.1.1
  Backup Designated router (ID)  3.3.3 .3, Interface address 199.99.1.3
  Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5
    oob-resync timeout 120
    Hello due in 00:00:25
  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 1, Adjacent neighbor count is 1
    Adjacent with neighbor 100.100.100.100  (Designated Router)
  Suppress hello for 0 neighbor(s)
 
要注意在这里用红色标记的部分,接口类型为 NON_BROADCAST ,默认的 HELLO 时间间隔为 30 秒,等待时间和死亡时间为 HELLO 时间间隔的四倍,也就是 120 秒。然后再用 show ip ospf neighbor 查看各自的邻居关系:
R1#show ip ospf neighbor
 
Neighbor ID     Pri   State           Dead Time   Address         Interface
2.2.2 .2           1   FULL/DROTHER    00:01:50    199.99.1.2      Serial1/0
3.3.3 .3           1   FULL/BDR        00:01:47    199.99.1.3      Serial1/0
 
 
R2#show ip ospf neighbor
 
Neighbor ID     Pri   State           Dead Time   Address         Interface
100.100.100.100   1   FULL/DR         00:01:38    199.99.1.1      Serial1/0
 
 
R3#show ip ospf neighbor
 
Neighbor ID     Pri   State           Dead Time   Address         Interface
100.100.100.100   1   FULL/DR         00:01:33    199.99.1.1      Serial1/0
 
可以发现有 DR/BDR 的选择,一般情况下 DR hub 路由器担当。 所以这里我们把 hub 路由器的 router-id 设置为最高,或者修改优先级也可以做到使 hub 路由器成为 DR 的目的,如在 R2 R3 的接口下打上这样的一条命令: ip ospf priority 0 , 配置完后就可以使 R2 R3 丧失 DR/BDR 的选举。
  最后查看以下各自的路由表:
R1#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O -  OSPF IA  - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route
 
Gateway of last resort is not set
 
      2.0.0 .0/24 is subnetted, 1 subnets
O        2.2.2 .0 [110/65] via 199.99.1.2, 00:01:40, Serial1/0
     100.0.0.0/24 is subnetted, 1 subnets
C       100.100.100.0 is directly connected, Loopback0
      3.0.0 .0/24 is subnetted, 1 subnets
O        3.3.3 .0 [110/65] via 199.99.1.3, 00:01:40, Serial1/0
C    199.99.1.0/24 is directly connected, Serial1/0
C    192.168.1.0/24 is directly connected, Loopback1
O    192.168.2.0/24 [110/65] via 199.99.1.2, 00:01:40, Serial1/0
O    192.168.3.0/24 [110/65] via 199.99.1.3, 00:01:40, Serial1/0
 
R2#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O -  OSPF IA  - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route
 
Gateway of last resort is not set
 
      2.0.0 .0/24 is subnetted, 1 subnets
C        2.2.2 .0 is directly connected, Loopback0
     100.0.0.0/24 is subnetted, 1 subnets
O       100.100.100.0 [110/65] via 199.99.1.1, 00:01:45, Serial1/0
      3.0.0 .0/24 is subnetted, 1 subnets
O        3.3.3 .0 [110/65] via 199.99.1.3, 00:01:45, Serial1/0
C    199.99.1.0/24 is directly connected, Serial1/0
O    192.168.1.0/24 [110/65] via 199.99.1.1, 00:01:45, Serial1/0
C    192.168.2.0/24 is directly connected, Loopback1
O    192.168.3.0/24 [110/65] via 199.99.1.3, 00:01:45, Serial1/0
 
R3#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O -  OSPF IA  - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route
 
Gateway of last resort is not set
 
      2.0.0 .0/24 is subnetted, 1 subnets
O        2.2.2 .0 [110/65] via 199.99.1.2, 00:01:41, Serial1/0
     100.0.0.0/24 is subnetted, 1 subnets
O       100.100.100.0 [110/65] via 199.99.1.1, 00:01:41, Serial1/0
      3.0.0 .0/24 is subnetted, 1 subnets
C        3.3.3 .0 is directly connected, Loopback0
C    199.99.1.0/24 is directly connected, Serial1/0
O    192.168.1.0/24 [110/65] via 199.99.1.1, 00:01:41, Serial1/0
O    192.168.2.0/24 [110/65] via 199.99.1.2, 00:01:41, Serial1/0
C    192.168.3.0/24 is directly connected, Loopback1
 
实验中遇到的问题:最初的时候我只在 R2 R3 上作了一个静态的映射,就是到 R1 的映射,自己以为可以通过 OSPF 学习到到达对端 sopke 路由器的路由,可是都配置完成后发现无法 ping 通,查看路由表的时候发现了问题的所在:
C    199.99.1.0/24 is directly connected, Serial1/0
看到了吧,因为三台路由器的 IP 地址在同一网段,所以直连的路由的管理距离为 0 ,而 OSPF 的管理距离为 110 ,所以路由表里只会出现直接的路由,但是如果要达到对端 spoke 路由器,没有做静态映射是无法到达的,所以才出现了 R2 无法 ping R3 的情况:
R2#ping 199.99.1.3
 
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 199.99.1.3, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
 
R2#ping  3.3.3 .3
 
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to  3.3.3 .3, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
分别在 R2 R3 上加上到达对端 spoke 路由器的静态映射后,就可以 ping 通了。
R2#ping 192.168.3.1
 
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.3.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 264/340/428 ms
R2#ping
Protocol [ip]:
Target IP address: 192.168.3.1
Repeat count [5]:
Datagram size [100]:
Timeout in seconds [2]:
Extended commands [n]: y
Source address or interface: 192.168.2.1
Type of service [0]:
Set DF bit in IP header? [no]:
Validate reply data? [no]:
Data pattern [0xABCD]:
Loose, Strict, Record, Timestamp, Verbose[none]:
Sweep range of sizes [n]:
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.3.1, timeout is 2 seconds:
Packet sent with a source address of 192.168.2.1
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 332/354/384 ms


实验总结:掌握在 NBMA 环境下面,接口默认的网络类型为 NBMA ,邻居关系不会自动建立,需要手动添加邻居,并且有 DR/BDR 的选举,默认的 HELLO 时间间隔为 30 秒,等待时间和死亡时间为 HELLO 时间间隔的 4 倍, 120 秒。





















本文转自loveme2351CTO博客,原文链接 http://blog.51cto.com/loveme23/46097 : ,如需转载请自行联系原作者

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