IP : 开放最短路径优先 (OSPF)

基于广播媒介的 OSPF 的初始配置

2016 年 10 月 24 日 - 机器翻译
其他版本: PDFpdf | 英语 (2015 年 8 月 22 日) | 反馈


目录


简介

本文档说明了广播介质(例如,以太网和令牌环)上的 Open Shortest Path First (OSPF) 配置示例。show ip ospf interface 命令会验证在所有广播介质上运行的 OSPF 是否默认为广播网络类型。

先决条件

要求

本文档的读者应掌握以下这些主题的相关知识:

使用的组件

本文档中的信息适用于以下软件和硬件版本。

  • 两个 Cisco 2501 路由器

  • Cisco IOSï ¿  ½软件版本12.2(27)

本文档中的信息都是基于特定实验室环境中的设备编写的。本文档中使用的所有设备最初均采用原始(默认)配置。如果您使用的是真实网络,请确保您已经了解所有命令的潜在影响。

相关产品

您还可以将此配置用于任意两个至少包含一个以太网、令牌环或 FDDI 接口的路由器。

规则

有关文档规则的详细信息,请参阅 Cisco 技术提示规则

配置

本部分为您提供了可用于配置本文档所述功能的信息。

注意: 要查找有关本文档所使用命令的其他信息,请参阅 OSPF 命令或使用命令查找工具仅限注册用户)。

网络图

本文档使用此网络设置。

/image/gif/paws/13686/14a.gif

配置

本文档使用以下配置。

Router1
interface Loopback0
�ip address 192.168.45.1 255.255.255.0
!
interface Ethernet0
�ip address 10.10.10.1 255.255.255.0
!
router ospf 1
�network 10.10.10.0 0.0.0.255 area 0

!--- OSPF is configured to run on the 
!--- Ethernet interface with an Area ID of 1.
 
!��� 

Router2
interface Loopback0
�ip address 172.16.10.1 255.255.255.0
!
interface Ethernet0
�ip address 10.10.10.2 255.255.255.0
!
router ospf 1
�network 10.10.10.0 0.0.0.255 area 0

!--- OSPF is configured to run on the 
!--- Ethernet interface with an Area ID of 1.

!   

验证

本部分提供的信息可帮助您确认您的配置是否可正常运行。

命令输出解释程序工具仅限注册用户)支持某些 show 命令,使用此工具可以查看对 show 命令输出的分析。

Router1#show ip ospf neighbor

 Neighbor ID���Pri����State��������� Dead Time����� Address������ Interface
 172.16.10.1����1�����FULL/BDR������ 00:00:38���� 10.10.10.2����� Ethernet0

在此输出中,Router1 的邻居状态是“Full”,Router2 的邻居 ID 是 172.16.10.1。Router2 在此广播网络中是备用指定路由器 (BDR)。要了解有关 show ip ospf neighbor 命令显示内容的详细信息,请参阅 show ip ospf neighbor 命令显示什么内容?

  • show ip ospf interface - 显示与 OSPF 相关的接口信息。在以太网接口上发出的 Router1 的输出如下所示:

Router1#show ip ospf interface ethernet 0
�� Ethernet0 is up, line protocol is up�
�� Internet Address 10.10.10.1/24, Area 0�
�� Process ID 1, Router ID 192.168.45.1, Network Type BROADCAST, Cost: 10
�� Transmit Delay is 1 sec, State DR, Priority 1�
�� Designated Router (ID) 192.168.45.1, Interface address 10.10.10.1
�� Backup Designated router (ID) 172.16.10.1, Interface address 10.10.10.2
�� Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
�� Hello due in 00:00:00
�� Index 2/2, flood queue length 0
�� Next 0x0(0)/0x0(0)
�� Last flood scan length is 2, maximum is 2
�� Last flood scan time is 0 msec, maximum is 0 msec
�� Neighbor Count is 1, Adjacent neighbor count is 1�
�� Adjacent with neighbor 172.16.10.1 (Backup Designated Router)
�� Suppress hello for 0 neighbor(s)

从此输出可以了解到,以太网 0 接口的网络类型为广播。要了解有关 show ip ospf interface 命令显示内容的详细信息,请参阅 show ip ospf interface 命令显示什么内容?

同样,在 Router2 上,show 命令的输出如下所示。

Router2#show ip ospf neighbor

 Neighbor ID��� Pri����State������ Dead Time������ Address������� Interface
�192.168.45.1��� 1�����FULL/DR������ 00:00:31����� 10.10.10.1������ Ethernet0

show ip ospf neighbor 命令的输出可以了解到,Router1 是此广播网络中的指定路由器 (DR)。

Router2#show ip ospf interface ethernet 0
���� Ethernet0 is up, line protocol is up�
���� Internet Address 10.10.10.2/24, Area 0�
���� Process ID 1, Router ID 172.16.10.1, Network Type BROADCAST, Cost: 10
���� Transmit Delay is 1 sec, State BDR, Priority 1�
���� Designated Router (ID) 192.168.45.1, Interface address 10.10.10.1
���� Backup Designated router (ID) 172.16.10.1, Interface address 10.10.10.2
���� Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
���� Hello due in 00:00:00
���� 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 192.168.45.1 (Designated Router)
���� Suppress hello for 0 neighbor(s)

Router2 的 show ip ospf interface ethernet 0 命令输出也显示以太网 0 接口的网络类型为广播。

故障排除

本部分提供的信息可用于对配置进行故障排除。

故障排除命令

命令输出解释程序工具仅限注册用户)支持某些 show 命令,使用此工具可以查看对 show 命令输出的分析。

注意: 在发出 debug 命令之前,请参阅有关 debug 命令的重要信息

两个路由器之间形成邻接时,会有多种状态。您可以使用 debug ip ospf adj 命令来查看各种状态,以及在广播 OSPF 网络中发生的 DR 和 BDR 选择。在较早的 Cisco IOS 软件版本中,您可以使用 debug ip ospf adjacency 命令。您需要在邻居关系建立之前发出此 debug 命令。

以下输出来自 Router1。输出中以粗体字显示的部分是邻接进程经历的各种状态。

Router1#debug ip ospf adj
OSPF adjacency events debugging is on

*Mar  1 01:41:23.319: OSPF: Rcv DBD from 172.16.10.1 on Ethernet0 seq 0x1F6C opt
 0x42 flag 0x7 len 32  mtu 1500 state INIT
*Mar  1 01:41:23.323: OSPF: 2 Way Communication to 172.16.10.1 
 on Ethernet0, state 2WAY
*Mar  1 01:41:23.327: OSPF: Neighbor change Event on interface Ethernet0
*Mar  1 01:41:23.327: OSPF: DR/BDR election on Ethernet0
*Mar  1 01:41:23.331: OSPF: Elect BDR 172.16.10.1
*Mar  1 01:41:23.331: OSPF: Elect DR 192.168.45.1
*Mar  1 01:41:23.335:        DR: 192.168.45.1 (Id)   BDR: 172.16.10.1 (Id)
*Mar  1 01:41:23.339: OSPF: Send DBD to 172.16.10.1 on Ethernet0 seq 0x2552 opt
0x42 flag 0x7 len 32
*Mar  1 01:41:23.343: OSPF: First DBD and we are not SLAVE
*Mar  1 01:41:23.359: OSPF: Rcv DBD from 172.16.10.1 on Ethernet0 seq 0x2552 opt
 0x42 flag 0x2 len 52  mtu 1500 state EXSTART
*Mar  1 01:41:23.363: OSPF: NBR Negotiation Done. We are the MASTER
*Mar  1 01:41:23.367: OSPF: Send DBD to 172.16.10.1 on Ethernet0 seq 0x2553 opt
0x42 flag 0x3 len 72
*Mar  1 01:41:23.387: OSPF: Rcv DBD from 172.16.10.1 on Ethernet0 seq 0x2553 opt
 0x42 flag 0x0 len 32  mtu 1500 state EXCHANGE
*Mar  1 01:41:23.391: OSPF: Send DBD to 172.16.10.1 on Ethernet0 seq 0x2554 opt
0x42 flag 0x1 len 32
*Mar  1 01:41:23.411: OSPF: Rcv DBD from 172.16.10.1 on Ethernet0 seq 0x2554 opt
 0x42 flag 0x0 len 32  mtu 1500 state EXCHANGE
*Mar  1 01:41:23.415: OSPF: Exchange Done with 172.16.10.1 on Ethernet0
*Mar  1 01:41:23.419: OSPF: Synchronized with 172.16.10.1 on Ethernet0, state FULL
01:41:23: %OSPF-5-ADJCHG: Process 1, Nbr 172.16.10.1 on Ethernet0 
 from LOADING to FULL, Loading Done
*Mar  1 01:41:23.879: OSPF: Build router LSA for area 0, router ID 192.168.45.1,
 seq 0x80000004
*Mar  1 01:41:23.923: OSPF: Build network LSA for Ethernet0, router ID 192.168.45.1
*Mar  1 01:41:25.503: OSPF: Neighbor change Event on interface Ethernet0
*Mar  1 01:41:25.507: OSPF: DR/BDR election on Ethernet0
*Mar  1 01:41:25.507: OSPF: Elect BDR 172.16.10.1
*Mar  1 01:41:25.511: OSPF: Elect DR 192.168.45.1
*Mar  1 01:41:25.511:        DR: 192.168.45.1 (Id)   BDR: 172.16.10.1 (Id)

发出 debug ip ospf events 命令可验证 hello 计时器值,如此示例输出所示。

Router1#debug ip ospf events
OSPF events debugging is on
Router1#
*Mar  1 04:04:11.926: OSPF: Rcv hello from 172.16.10.1 area 0 from 
  Ethernet0 10.10.10.2
*Mar  1 04:04:11.930: OSPF: End of hello processing
*Mar  1 04:04:21.926: OSPF: Rcv hello from 172.16.10.1 
  area 0 from Ethernet0 10.10.10.2
*Mar  1 04:04:21.930: OSPF: End of hello processing
*Mar  1 04:04:31.926: OSPF: Rcv hello from 172.16.10.1 area 0 from 
  Ethernet0 10.10.10.2
*Mar  1 04:04:31.930: OSPF: End of hello processing
*Mar  1 04:04:41.926: OSPF: Rcv hello from 172.16.10.1 area 0 from 
  Ethernet0 10.10.10.2
*Mar  1 04:04:41.930: OSPF: End of hello processing
*Mar  1 04:04:51.926: OSPF: Rcv hello from 172.16.10.1 area 0 from 
  Ethernet0 10.10.10.2
*Mar  1 04:04:51.930: OSPF: End of hello processing
*Mar  1 04:05:01.926: OSPF: Rcv hello from 172.16.10.1 area 0 from 
  Ethernet0 10.10.10.2
*Mar  1 04:05:01.930: OSPF: End of hello processing
*Mar  1 04:05:11.926: OSPF: Rcv hello from 172.16.10.1 area 0 from 
  Ethernet0 10.10.10.2
*Mar  1 04:05:11.930: OSPF: End of hello processing
*Mar  1 04:05:21.926: OSPF: Rcv hello from 172.16.10.1 area 0 from 
  Ethernet0 10.10.10.2
*Mar  1 04:05:21.930: OSPF: End of hello processing

此输出显示 Hello 数据包每 10 秒交换一次。


相关信息


Document ID: 13686