目录
实验原理
案例
路由器配置单区域OSPF基本功能
单区域总结
路由器配置多区域OSPF基本功能
多区域特点
实验原理
OSPF（Open Shortest Path First，开放最短路径优先）是互联网的标准协议，是为克服RIP的缺点而开发的。目前针对IPv4协议使用的 是OSPFv2。OSPF最主要的特征就是使用分布式的链路状态协议（Link State Protocol）。当链路状态发生变化时，OSPF路由器使用可靠的洪泛法 （Flooding）向本自治系统中所有路由器发送信息，发送的信息是与本 路由器相邻的所有路由器的链路状态，包括：本路由器与哪些路由器相邻，以及该链路的“度量”（Metric）等。
由于一个路由器的链路状态只涉及到与相邻路由器的连通状态，而 与整个互联网的规模并无直接关系，因此当互联网规模很大时，OSPF 协议要比距离向量协议RIP好得多。
所 有 的 路 由 器 都 维 护 一 个 链 路 状 态 数 据 库 （ Link State DataBase，LSDB），这个数据库实际上就是全网的拓扑结构图。这个拓扑结构图在全网范围内是一致的（这称为链路状态数据库的同步）。每一个路由器使用链路状态数据库中的数据，构造出自己的路由表（例如，使用Dijkstra的最短路径路由算法）。OSPF的链路状态数据库能较快地进行更新，使各个路由器能及时更新其路由表。OSPF 的更新过程 收敛得快，没有“坏消息传播得慢”的问题，不会产生路由环路。
为了使 OSPF 能够用于规模很大的网络，OSPF 将一个自治系统再划分为若干个更小的范围，叫作区域（Area）。区域内的详细拓扑信息不向其他区域发送，区域间传递的是聚合的路由信息，而不是详细的描 述拓扑结构的链路状态信息，减少了整个网络上的通信量。每个区域都 有自己的LSDB，不同区域的LSDB是不同的。
为了使每一个区域能够和本区域以外的区域进行通信，OSPF使用层次结构的区域划分，将区域分为两层，在上层的区域叫作主干区域 （Backbone Area），用于连通其他在下层的区域。主干区域的标识符规定为0.0.0.0。下层区域都通过主干区域实现区域之间的通信。在一 个采用OSPF的自治系统中，只能有一个主干区域。
OSPF直接使用 IP 数据报传送 OSPF分组，协议号为 89。OSPF 有 五种类型的分组：Hello（问候）分组、DD（Database Description， 数据库描述）分组、LSR（Link State Request，链路状态请求）分 组、LSU（Link State Update，链路状态更新）分组和 LSA（Link State Acknowledgment，链路状态确认）分组。每个OSPF分组构成的数据报很短，不需要分片。
此外，OSPF对不同的链路可根据IP分组的不同服务类型TOS而设置 成不同的代价。因此，OSPF 对于不同类型的业务可计算出不同的路 由。如果到同一个目的网络有多条相同代价的路径，那么可以将通信量 分配给这几条路径，实现多路径间的负载平衡。
所有在 OSPF 路由器之间交换的分组都具有鉴别的功能。OSPF支持可变长度的子网划分和无分类编址CIDR。
由于网络中的链路状态可能经常发生变化，因此OSPF让每一个链路状态都带上一个32位的序号，序号越大，状态就越新。
对 于 多 点 接 入 的 局 域 网 ， OSPF协议采用了指定路由器（Designated Router）的方法，使广播的信息量大大减少。指定的路由器代表该局域网上所有的链路向连接到该网络上的各OSPF路由器发送状态信息。
案例
路由器配置单区域OSPF基本功能
具体配置如下
配置路由器RTA
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sysname RTSA
[RTSA]sysname RTA
#配置连接计算机端口的ip地址
[RTA]interface g0/0/2
[RTA-GigabitEthernet0/0/2]ip address 10.1.10.1 24
Sep 23 2023 10:35:40-08:00 RTA %%01IFNET/4/LINK_STATE(l)[0]:The line protocol IPon the interface GigabitEthernet0/0/2 has entered the UP state.
[RTA-GigabitEthernet0/0/2]qu
[RTA]undo info-center enable
Info: Information center is disabled.
[RTA]qu
#配置连接路由器的端口的IP地址
[RTA]int g0/0/0
[RTA-GigabitEthernet0/0/0]ip address 172.16.101.1 24
[RTA-GigabitEthernet0/0/0]qu
配置路由器RTB
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sysname RTB
[RTB]int g0/0/0
[RTB-GigabitEthernet0/0/0]ip address 172.16.101.2 24
Sep 23 2023 10:37:20-08:00 RTB %%01IFNET/4/LINK_STATE(l)[0]:The line protocol IPon the interface GigabitEthernet0/0/0 has entered the UP state.
[RTB-GigabitEthernet0/0/0]qu
[RTB]int g0/0/1
[RTB-GigabitEthernet0/0/1]ip address 172.16.102.1 24
Sep 23 2023 10:37:34-08:00 RTB %%01IFNET/4/LINK_STATE(l)[1]:The line protocol IPon the interface GigabitEthernet0/0/1 has entered the UP state.
[RTB-GigabitEthernet0/0/1]qu配置路由器RTC
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sysname RTC
[RTC]int g0/0/0
[RTC-GigabitEthernet0/0/0]ip address 172.16.103.2 24
Sep 23 2023 10:38:03-08:00 RTC %%01IFNET/4/LINK_STATE(l)[0]:The line protocol IPon the interface GigabitEthernet0/0/0 has entered the UP state.
[RTC-GigabitEthernet0/0/0]
[RTC-GigabitEthernet0/0/0]qu
[RTC]undo info-center enable
Info: Information center is disabled.
[RTC]int g0/0/1
[RTC-GigabitEthernet0/0/1]ip address 172.16.102.2 24
[RTC-GigabitEthernet0/0/1]qu配置路由器RTD
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sysname RTD
[RTD]int g0/0/2
[RTD-GigabitEthernet0/0/2]ip address 11.1.50.1 24
Sep 23 2023 10:40:24-08:00 RTD %%01IFNET/4/LINK_STATE(l)[0]:The line protocol IPon the interface GigabitEthernet0/0/2 has entered the UP state.
[RTD-GigabitEthernet0/0/2]qu
[RTD]int g0/0/0
[RTD-GigabitEthernet0/0/0]ip address 172.16.103.1 24
[RTD-GigabitEthernet0/0/0]
Sep 23 2023 10:40:38-08:00 RTD %%01IFNET/4/LINK_STATE(l)[1]:The line protocol IPon the interface GigabitEthernet0/0/0 has entered the UP state.
[RTD-GigabitEthernet0/0/0]qu
[RTD]配置各路由器的单区域OSPF基本功能
<RTA>sys
Enter system view, return user view with Ctrl+Z.
# 路由器的 Router ID是一台路由器在自治系统中的唯一标识，是一个 32 比特无符号整数，用点分十进制数表示。默认情况下，路由器系统会从当前接口的 IP 地址中自动选取一个最大值作为 Router ID。手动配置 Router ID时，必须保证自治系统中任意两台 Router ID都不相同。通常的做法是将RouterID配置为与该设备某个端口的 IP地址一致
[RTA]router id 10.1.10.1
Info: Router ID has been modified, please reset the relative protocols manually
to update the Router ID.
#使能OSPF进程，指定OSPF进程为1，进程号取值范围是1~65535。默认值是1
[RTA]ospf 1
#创建区域，单区域只有一个主干区域。主干区域编号为0
[RTA-ospf-1]area 0
# 指定运行OSPE接口和接口所属区域
# OSPF使用反掩码，例如0.0.0.255表示掩码长度为24位
# 接口的 IP 地址掩码长度必须大于等于 network 命令中的掩码长度，且接口不带子网的 IP 地址必须在network命令指定的网段范围之内。
# undo network命令用来删除运行OSPE协议的接口
# 默认情况下，接口不属于任何区域。
[RTA-ospf-1-area-0.0.0.0]network 10.1.10.0 0.0.0.255
[RTA-ospf-1-area-0.0.0.0]network 172.16.101.0 0.0.0.255
[RTA-ospf-1-area-0.0.0.0]qu
[RTA-ospf-1]qu
[RTA]display IP routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: PublicDestinations : 10 Routes : 10 Destination/Mask Proto Pre Cost Flags NextHop Interface10.1.10.0/24 Direct 0 0 D 10.1.10.1 GigabitEthernet
0/0/210.1.10.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/210.1.10.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/2127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0172.16.101.0/24 Direct 0 0 D 172.16.101.1 GigabitEthernet
0/0/0172.16.101.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0172.16.101.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0[RTA]display IP routing-table protocol ospf<RTB>sys
Enter system view, return user view with Ctrl+Z.
[RTB]router id 172.16.101.2
[RTB]ospf 1
[RTB-ospf-1]area 0
[RTB-ospf-1-area-0.0.0.0]network 172.16.101.0 0.0.0.255
[RTB-ospf-1-area-0.0.0.0]network 172.16.102.0 0.0.0.255
[RTB-ospf-1-area-0.0.0.0]qu
[RTB-ospf-1]qu
[RTB]display IP routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: PublicDestinations : 11 Routes : 11 Destination/Mask Proto Pre Cost Flags NextHop Interface10.1.10.0/24 OSPF 10 2 D 172.16.101.1 GigabitEthernet
0/0/0127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0172.16.101.0/24 Direct 0 0 D 172.16.101.2 GigabitEthernet
0/0/0172.16.101.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0172.16.101.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0172.16.102.0/24 Direct 0 0 D 172.16.102.1 GigabitEthernet
0/0/1172.16.102.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1172.16.102.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0[RTB]display IP routing-table protocol ospf
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Public routing table : OSPFDestinations : 1 Routes : 1 OSPF routing table status : <Active>Destinations : 1 Routes : 1Destination/Mask Proto Pre Cost Flags NextHop Interface10.1.10.0/24 OSPF 10 2 D 172.16.101.1 GigabitEthernet
0/0/0OSPF routing table status : <Inactive>Destinations : 0 Routes : 0<RTC>sys
Enter system view, return user view with Ctrl+Z.
[RTC]router id 172.16.103.2
Info: Router ID has been modified, please reset the relative protocols manually
to update the Router ID.
[RTC]ospf 1
[RTC-ospf-1]area 0
[RTC-ospf-1-area-0.0.0.0]network 172.16.102.0 0.0.0.255
[RTC-ospf-1-area-0.0.0.0]network 172.16.103.0 0.0.0.255
[RTC-ospf-1-area-0.0.0.0]qu
[RTC-ospf-1]qu
[RTC]display IP routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: PublicDestinations : 12 Routes : 12 Destination/Mask Proto Pre Cost Flags NextHop Interface10.1.10.0/24 OSPF 10 3 D 172.16.102.1 GigabitEthernet
0/0/1127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0172.16.101.0/24 OSPF 10 2 D 172.16.102.1 GigabitEthernet
0/0/1172.16.102.0/24 Direct 0 0 D 172.16.102.2 GigabitEthernet
0/0/1172.16.102.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1172.16.102.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1172.16.103.0/24 Direct 0 0 D 172.16.103.2 GigabitEthernet
0/0/0172.16.103.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0172.16.103.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0[RTC]display IP routing-table protocol ospf
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Public routing table : OSPFDestinations : 2 Routes : 2 OSPF routing table status : <Active>Destinations : 2 Routes : 2Destination/Mask Proto Pre Cost Flags NextHop Interface10.1.10.0/24 OSPF 10 3 D 172.16.102.1 GigabitEthernet
0/0/1172.16.101.0/24 OSPF 10 2 D 172.16.102.1 GigabitEthernet
0/0/1OSPF routing table status : <Inactive>Destinations : 0 Routes : 0<RTD>sys
Enter system view, return user view with Ctrl+Z.
[RTD]ospf 1
[RTD-ospf-1]area 0
[RTD-ospf-1-area-0.0.0.0]network 11.1.50.0 0.0.0.255
[RTD-ospf-1-area-0.0.0.0]network 172.16.103.0 0.0.0.255
[RTD-ospf-1-area-0.0.0.0]qu
[RTD-ospf-1]
Sep 23 2023 11:18:11-08:00 RTD %%01OSPF/4/NBR_CHANGE_E(l)[0]:Neighbor changes ev
ent: neighbor status changed. (ProcessId=256, NeighborAddress=2.103.16.172, Neig
hborEvent=HelloReceived, NeighborPreviousState=Down, NeighborCurrentState=Init) [RTD-ospf-1]
Sep 23 2023 11:18:11-08:00 RTD %%01OSPF/4/NBR_CHANGE_E(l)[1]:Neighbor changes ev
ent: neighbor status changed. (ProcessId=256, NeighborAddress=2.103.16.172, Neig
hborEvent=2WayReceived, NeighborPreviousState=Init, NeighborCurrentState=2Way)
[RTD-ospf-1]
Sep 23 2023 11:18:11-08:00 RTD %%01OSPF/4/NBR_CHANGE_E(l)[2]:Neighbor changes ev
ent: neighbor status changed. (ProcessId=256, NeighborAddress=2.103.16.172, Neig
hborEvent=AdjOk?, NeighborPreviousState=2Way, NeighborCurrentState=ExStart)
[RTD-ospf-1]
Sep 23 2023 11:18:11-08:00 RTD %%01OSPF/4/NBR_CHANGE_E(l)[3]:Neighbor changes ev
ent: neighbor status changed. (ProcessId=256, NeighborAddress=2.103.16.172, Neig
hborEvent=NegotiationDone, NeighborPreviousState=ExStart, NeighborCurrentState=E
xchange)
[RTD-ospf-1]
Sep 23 2023 11:18:11-08:00 RTD %%01OSPF/4/NBR_CHANGE_E(l)[4]:Neighbor changes ev
ent: neighbor status changed. (ProcessId=256, NeighborAddress=2.103.16.172, Neig
hborEvent=ExchangeDone, NeighborPreviousState=Exchange, NeighborCurrentState=Loa
ding)
[RTD-ospf-1]
Sep 23 2023 11:18:11-08:00 RTD %%01OSPF/4/NBR_CHANGE_E(l)[5]:Neighbor changes ev
ent: neighbor status changed. (ProcessId=256, NeighborAddress=2.103.16.172, Neig
hborEvent=LoadingDone, NeighborPreviousState=Loading, NeighborCurrentState=Full)[RTD-ospf-1]qu
[RTD]display IP routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: PublicDestinations : 13 Routes : 13 Destination/Mask Proto Pre Cost Flags NextHop Interface10.1.10.0/24 OSPF 10 4 D 172.16.103.2 GigabitEthernet
0/0/011.1.50.0/24 Direct 0 0 D 11.1.50.1 GigabitEthernet
0/0/211.1.50.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/211.1.50.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/2127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0172.16.101.0/24 OSPF 10 3 D 172.16.103.2 GigabitEthernet
0/0/0172.16.102.0/24 OSPF 10 2 D 172.16.103.2 GigabitEthernet
0/0/0172.16.103.0/24 Direct 0 0 D 172.16.103.1 GigabitEthernet
0/0/0172.16.103.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0172.16.103.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0[RTD]display IP routing-table protocol ospf
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Public routing table : OSPFDestinations : 3 Routes : 3 OSPF routing table status : <Active>Destinations : 3 Routes : 3Destination/Mask Proto Pre Cost Flags NextHop Interface10.1.10.0/24 OSPF 10 4 D 172.16.103.2 GigabitEthernet
0/0/0172.16.101.0/24 OSPF 10 3 D 172.16.103.2 GigabitEthernet
0/0/0172.16.102.0/24 OSPF 10 2 D 172.16.103.2 GigabitEthernet
0/0/0OSPF routing table status : <Inactive>Destinations : 0 Routes : 0可以通过以下命令查看配置结果
# 查看OSPE 的概要信息
<RTA> display ospf brief
<RTA> display ospf 1 brief# 查看OSPE的接口信息
<RTA> display ospf interface all
<RTA> display ospf l interface gigabitethernet 0/0/0# 查看OSPE的链路状态数据库(LSDB)详细信息
<RTA> display ospf lsdb
<RTA> display ospf 1 lsdb
# 查看OSPE的链路状态数据库(LSDB)概要信息
<RTA> display ospf lsdb brief
<RTA> display ospf 1 lsdb brief
# 查看OSPE链路状态数据库中 Router LSA的相关信息
<RTA> display ospf lsdb router
<RTA> display ospf 1 lsdb router
# 查看OSPE链路状态数据库中 Network LSA的相关信息
<RTA> display ospf lsdb network 10.1.10.1
<RTA> display ospf 1 lsdb network 172.16.101.0
# 查看 OSPE 中各区域邻居的详细信息
<RTA> display ospf peer
# 查看 OSPE 中各区域邻居的概要信息
<RTA> display ospf l peer brief
# 查看OSPE路由表的信息。
<RTA> display ospf routing
<RTA> display ospf 1 routing router-id 172.16.103.2# 查看路由器 IP路由表。
<RTA> display IP routing-table#查看路由器IP路由表中的OSPE路由
<RTA> displayIP routing-table protocol ospf
PC端互ping结果如下
PC>ping 11.1.50.11Ping 11.1.50.11: 32 data bytes, Press Ctrl_C to break
Request timeout!
From 11.1.50.11: bytes=32 seq=2 ttl=124 time=31 ms
From 11.1.50.11: bytes=32 seq=3 ttl=124 time=16 ms
From 11.1.50.11: bytes=32 seq=4 ttl=124 time=31 ms
From 11.1.50.11: bytes=32 seq=5 ttl=124 time=32 ms--- 11.1.50.11 ping statistics ---5 packet(s) transmitted4 packet(s) received20.00% packet lossround-trip min/avg/max = 0/27/32 msPC>tracert 11.1.50.11traceroute to 11.1.50.11, 8 hops max
(ICMP), press Ctrl+C to stop1 10.1.10.1 16 ms 15 ms 16 ms2 172.16.101.2 16 ms 15 ms 16 ms3 172.16.102.2 31 ms 16 ms 31 ms4 172.16.103.1 16 ms 31 ms 31 ms5 11.1.50.11 31 ms 16 ms 31 msPC>ping 10.1.10.11Ping 10.1.10.11: 32 data bytes, Press Ctrl_C to break
From 10.1.10.11: bytes=32 seq=1 ttl=124 time=31 ms
From 10.1.10.11: bytes=32 seq=2 ttl=124 time=31 ms
From 10.1.10.11: bytes=32 seq=3 ttl=124 time=31 ms
From 10.1.10.11: bytes=32 seq=4 ttl=124 time=16 ms
From 10.1.10.11: bytes=32 seq=5 ttl=124 time=31 ms--- 10.1.10.11 ping statistics ---5 packet(s) transmitted5 packet(s) received0.00% packet lossround-trip min/avg/max = 16/28/31 msPC>tracert 10.1.10.11traceroute to 10.1.10.11, 8 hops max
(ICMP), press Ctrl+C to stop1 11.1.50.1 <1 ms 16 ms 15 ms2 172.16.103.2 16 ms 16 ms <1 ms3 172.16.102.1 31 ms 15 ms 16 ms4 172.16.101.1 16 ms 31 ms 31 ms5 10.1.10.11 31 ms 16 ms 31 ms对RTB的g0/0/0端口抓包，可以看出
1.ospf是通过IPv4协议进行分组的，使用的端口为89号端口
2.使用组播地址作为目的地址（224.0.0.5）
这里可以看他属于什么包，以及版本（version）
这里可以看到包的信息
关闭RTD的g0/0/0端口
<RTD>sys
Enter system view, return user view with Ctrl+Z.
[RTD]int g0/0/0
[RTD-GigabitEthernet0/0/0]shutdown
Sep 23 2023 13:32:31-08:00 RTD %%01IFPDT/4/IF_STATE(l)[0]:Interface GigabitEther
net0/0/0 has turned into DOWN state.
[RTD-GigabitEthernet0/0/0]
[RTD-GigabitEthernet0/0/0]
Sep 23 2023 13:32:31-08:00 RTD %%01IFNET/4/LINK_STATE(l)[1]:The line protocol IPon the interface GigabitEthernet0/0/0 has entered the DOWN state.
[RTD-GigabitEthernet0/0/0]
Sep 23 2023 13:32:31-08:00 RTD %%01OSPF/3/NBR_CHG_DOWN(l)[2]:Neighbor event:neig
hbor state changed to Down. (ProcessId=256, NeighborAddress=2.103.16.172, Neighb
orEvent=KillNbr, NeighborPreviousState=Full, NeighborCurrentState=Down)
[RTD-GigabitEthernet0/0/0]
Sep 23 2023 13:32:31-08:00 RTD %%01OSPF/3/NBR_DOWN_REASON(l)[3]:Neighbor state l
eaves full or changed to Down. (ProcessId=256, NeighborRouterId=2.103.16.172, Ne
ighborAreaId=0, NeighborInterface=GigabitEthernet0/0/0,NeighborDownImmediate rea
son=Neighbor Down Due to Kill Neighbor, NeighborDownPrimeReason=Physical Interfa
ce State Change, NeighborChangeTime=2023-09-23 13:32:31-08:00)
[RTD-GigabitEthernet0/0/0]在RTB的g0/0/0端口抓包，抓到了LSU,LSA
LSU信息如下
LSA信息如下
再次开启RTD的g0/0/0端口
<RTD>sys
Enter system view, return user view with Ctrl+Z.
[RTD]int g0/0/0
[RTD-GigabitEthernet0/0/0]undo shutdown
[RTD-GigabitEthernet0/0/0]
Sep 23 2023 13:38:44-08:00 RTD %%01IFPDT/4/IF_STATE(l)[0]:Interface GigabitEther
net0/0/0 has turned into UP state.
[RTD-GigabitEthernet0/0/0]
Sep 23 2023 13:38:44-08:00 RTD %%01IFNET/4/LINK_STATE(l)[1]:The line protocol IPon the interface GigabitEthernet0/0/0 has entered the UP state. RTC的g0/0/0端口抓包信息如下
DD信息如下
LSR信息如下
LSU信息如下
LSA信息如下
单区域总结
•企业内网，如果仅仅配置一个区域，那必须是OSPF区域0，主干区域
•OSPF进程号的作用是：在同一个额路由器上区分不同的OSPF协议，不同路由器上的进程号可以相同也可以不相同。
•OSPF的Router-ID用于标识不同的路由器们必须确保全网唯一
•OSPF Ruter-id最大特点：稳定。一旦确定，就无法修改，除非重启OSPF协议或者重启路由器
路由器配置多区域OSPF基本功能
OSPF区域的类型：
- 骨干区域：area 0
- 非骨干区域：
- 普通区域
- 特殊区域：Stub区域、完全Stub区域、NSSA区域、完全NSSA区域
所有的非骨干区域，必须与骨干区域直接相连，否则区域之间无法互通
来看下面的案例：
在第一次配置的路由的基础上，配置多区域OSPF， 配置RTA
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sysname RTA
[RTA]router id 10.1.10.1
Info: Router ID has been modified, please reset the relative protocols manually
to update the Router ID.
[RTA]ospf 1
[RTA-ospf-1]area 1
[RTA-ospf-1-area-0.0.0.1]network 10.1.10.0 0.0.0.255
[RTA-ospf-1-area-0.0.0.1]network 172.16.101.0 0.0.0.255
[RTA-ospf-1-area-0.0.0.1]qu
[RTA-ospf-1]qu#路由器都配置ospf后
[RTA]display IP routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: PublicDestinations : 13 Routes : 13 Destination/Mask Proto Pre Cost Flags NextHop Interface10.1.10.0/24 Direct 0 0 D 10.1.10.1 GigabitEthernet
0/0/210.1.10.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/210.1.10.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/211.1.50.0/24 OSPF 10 4 D 172.16.101.2 GigabitEthernet
0/0/0127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0172.16.101.0/24 Direct 0 0 D 172.16.101.1 GigabitEthernet
0/0/0172.16.101.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0172.16.101.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0172.16.102.0/24 OSPF 10 2 D 172.16.101.2 GigabitEthernet
0/0/0172.16.103.0/24 OSPF 10 3 D 172.16.101.2 GigabitEthernet
0/0/0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0[RTA]display IP routing-table protocol ospf
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Public routing table : OSPFDestinations : 3 Routes : 3 OSPF routing table status : <Active>Destinations : 3 Routes : 3Destination/Mask Proto Pre Cost Flags NextHop Interface11.1.50.0/24 OSPF 10 4 D 172.16.101.2 GigabitEthernet
0/0/0172.16.102.0/24 OSPF 10 2 D 172.16.101.2 GigabitEthernet
0/0/0172.16.103.0/24 OSPF 10 3 D 172.16.101.2 GigabitEthernet
0/0/0OSPF routing table status : <Inactive>Destinations : 0 Routes : 0配置RTB
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sysname RTB
[RTB]router id 172.16.101.2
Info: Router ID has been modified, please reset the relative protocols manually
to update the Router ID.
[RTB]ospf 1[RTB-ospf-1]area 0
[RTB-ospf-1-area-0.0.0.0]network 172.16.102.0 0.0.0.255
[RTB-ospf-1-area-0.0.0.0]qu[RTB-ospf-1]area 1
[RTB-ospf-1-area-0.0.0.1]network 172.16.101.0 0.0.0.255
[RTB-ospf-1-area-0.0.0.1]qu
[RTB-ospf-1]qu#路由器都配置ospf后
[RTB]display IP routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: PublicDestinations : 13 Routes : 13 Destination/Mask Proto Pre Cost Flags NextHop Interface10.1.10.0/24 OSPF 10 2 D 172.16.101.1 GigabitEthernet
0/0/011.1.50.0/24 OSPF 10 3 D 172.16.102.2 GigabitEthernet
0/0/1127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0172.16.101.0/24 Direct 0 0 D 172.16.101.2 GigabitEthernet
0/0/0172.16.101.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0172.16.101.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0172.16.102.0/24 Direct 0 0 D 172.16.102.1 GigabitEthernet
0/0/1172.16.102.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1172.16.102.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1172.16.103.0/24 OSPF 10 2 D 172.16.102.2 GigabitEthernet
0/0/1
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0[RTB]display IP routing-table protocol ospf
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Public routing table : OSPFDestinations : 3 Routes : 3 OSPF routing table status : <Active>Destinations : 3 Routes : 3Destination/Mask Proto Pre Cost Flags NextHop Interface10.1.10.0/24 OSPF 10 2 D 172.16.101.1 GigabitEthernet
0/0/011.1.50.0/24 OSPF 10 3 D 172.16.102.2 GigabitEthernet
0/0/1172.16.103.0/24 OSPF 10 2 D 172.16.102.2 GigabitEthernet
0/0/1OSPF routing table status : <Inactive>Destinations : 0 Routes : 0配置RTC
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sysname RTC
[RTC]router id 172.16.103.2
Info: Router ID has been modified, please reset the relative protocols manually
to update the Router ID.
[RTC]ospf 1[RTC-ospf-1]area 0
[RTC-ospf-1-area-0.0.0.0]network 172.16.102.0 0.0.0.255
[RTC-ospf-1-area-0.0.0.0]qu[RTC-ospf-1]area 2
[RTC-ospf-1-area-0.0.0.2]network 172.16.103.0 0.0.0.255
[RTC-ospf-1-area-0.0.0.2]qu
[RTC-ospf-1]qu
[RTC]#各路由器都配置ospf后
[RTC]display IP routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: PublicDestinations : 13 Routes : 13 Destination/Mask Proto Pre Cost Flags NextHop Interface10.1.10.0/24 OSPF 10 3 D 172.16.102.1 GigabitEthernet
0/0/111.1.50.0/24 OSPF 10 2 D 172.16.103.1 GigabitEthernet
0/0/0127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0172.16.101.0/24 OSPF 10 2 D 172.16.102.1 GigabitEthernet
0/0/1172.16.102.0/24 Direct 0 0 D 172.16.102.2 GigabitEthernet
0/0/1172.16.102.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1172.16.102.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1172.16.103.0/24 Direct 0 0 D 172.16.103.2 GigabitEthernet
0/0/0172.16.103.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0172.16.103.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0[RTC]display IP routing-table protocol ospf
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Public routing table : OSPFDestinations : 3 Routes : 3 OSPF routing table status : <Active>Destinations : 3 Routes : 3Destination/Mask Proto Pre Cost Flags NextHop Interface10.1.10.0/24 OSPF 10 3 D 172.16.102.1 GigabitEthernet
0/0/111.1.50.0/24 OSPF 10 2 D 172.16.103.1 GigabitEthernet
0/0/0172.16.101.0/24 OSPF 10 2 D 172.16.102.1 GigabitEthernet
0/0/1OSPF routing table status : <Inactive>Destinations : 0 Routes : 0配置RTD
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sysname RTD
[RTD]router id 11.1.50.1
Info: Router ID has been modified, please reset the relative protocols manually
to update the Router ID.
[RTD]ospf 1[RTD-ospf-1]area 2
[RTD-ospf-1-area-0.0.0.2]network 11.1.50.0 0.0.0.255
[RTD-ospf-1-area-0.0.0.2]network 172.16.103.0 0.0.0.255
[RTD-ospf-1-area-0.0.0.2]qu
[RTD-ospf-1]qu
[RTD][RTD]display IP routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: PublicDestinations : 13 Routes : 13 Destination/Mask Proto Pre Cost Flags NextHop Interface10.1.10.0/24 OSPF 10 4 D 172.16.103.2 GigabitEthernet
0/0/011.1.50.0/24 Direct 0 0 D 11.1.50.1 GigabitEthernet
0/0/211.1.50.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/211.1.50.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/2127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0172.16.101.0/24 OSPF 10 3 D 172.16.103.2 GigabitEthernet
0/0/0172.16.102.0/24 OSPF 10 2 D 172.16.103.2 GigabitEthernet
0/0/0172.16.103.0/24 Direct 0 0 D 172.16.103.1 GigabitEthernet
0/0/0172.16.103.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0172.16.103.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0[RTD]display IP routing-table protocol ospf
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Public routing table : OSPFDestinations : 3 Routes : 3 OSPF routing table status : <Active>Destinations : 3 Routes : 3Destination/Mask Proto Pre Cost Flags NextHop Interface10.1.10.0/24 OSPF 10 4 D 172.16.103.2 GigabitEthernet
0/0/0172.16.101.0/24 OSPF 10 3 D 172.16.103.2 GigabitEthernet
0/0/0172.16.102.0/24 OSPF 10 2 D 172.16.103.2 GigabitEthernet
0/0/0OSPF routing table status : <Inactive>Destinations : 0 Routes : 0可以用以下命令查看配置结果
# 查看OSPE的概要信息。
<RTA>displayospf brief
<RTA> display ospf l brief
# 查看OSPE的接口信息。
<RTA> displayospf interface all
<RTA> display ospf interface gigabitethernet 0/0/0
#查看OSPE的链路状态数据库(LSDB)详细信息。
<RTA> display ospf lsdb
<RTA> display ospf 1lsdb
# 查看 OSPE的链路状态数据库(LSDB)概要信息
<RTA> display ospf lsdb brief
<RTA> displayospf1 lsdb brief
# 查看OSPE链路状态数据库中 Router LSA的相关信息
<RTA> display ospf lsdb router
<RTA> display ospf 1 lsdb router
# 查看OSPE链路状态数据库中Network LSA的相关信息
<RTA> display ospf lsdb network 10.1.10.1
<RTA> display ospf 1 lsdb network 172.16.101.0
# 查看OSPE 中各区域邻居的详细信息
<RTA>display ospf peer
#查看OSPE 中各区域邻居的概要信息
<RTA> display ospf l peer brief
# 查看OSPE路由表的信息。
<RTA> display ospf routing
<RTA> display ospf l routing router-id 172.16.103.2
#查看路由器IP路由表。
<RTA> display IP routing-table
# 查看路由器 IP路由表中的OSPE路由
<RTA> display IP routing-table protocol ospf
两个PC互ping
PC>ping 11.1.50.1Ping 11.1.50.1: 32 data bytes, Press Ctrl_C to break
From 11.1.50.1: bytes=32 seq=1 ttl=252 time=47 ms
From 11.1.50.1: bytes=32 seq=2 ttl=252 time=31 ms
From 11.1.50.1: bytes=32 seq=3 ttl=252 time=47 ms
From 11.1.50.1: bytes=32 seq=4 ttl=252 time=31 ms
From 11.1.50.1: bytes=32 seq=5 ttl=252 time=32 ms--- 11.1.50.1 ping statistics ---5 packet(s) transmitted5 packet(s) received0.00% packet lossround-trip min/avg/max = 31/37/47 msPC>tracert 11.1.50.11traceroute to 11.1.50.11, 8 hops max
(ICMP), press Ctrl+C to stop1 10.1.10.1 16 ms <1 ms 15 ms2 172.16.101.2 16 ms <1 ms 16 ms3 172.16.102.2 31 ms 15 ms 16 ms4 172.16.103.1 31 ms 32 ms 15 ms5 11.1.50.11 31 ms 32 ms 15 msPing 10.1.10.11: 32 data bytes, Press Ctrl_C to break
From 10.1.10.11: bytes=32 seq=1 ttl=124 time=31 ms
From 10.1.10.11: bytes=32 seq=2 ttl=124 time=31 ms
From 10.1.10.11: bytes=32 seq=3 ttl=124 time=32 ms
From 10.1.10.11: bytes=32 seq=4 ttl=124 time=31 ms
From 10.1.10.11: bytes=32 seq=5 ttl=124 time=31 ms--- 10.1.10.11 ping statistics ---5 packet(s) transmitted5 packet(s) received0.00% packet lossround-trip min/avg/max = 31/31/32 msPC>tracert 10.1.10.11traceroute to 10.1.10.11, 8 hops max
(ICMP), press Ctrl+C to stop1 11.1.50.1 15 ms <1 ms 16 ms2 172.16.103.2 15 ms 16 ms <1 ms3 172.16.102.1 31 ms 16 ms 31 ms4 172.16.101.1 16 ms 31 ms 16 ms5 10.1.10.11 31 ms 31 ms 16 ms
跟上个实验一样，关闭RTD的g0/0/0端口，对RTB的g0/0/0端口进行抓包，可以看到ospf的包明显增多了(LSU,LSA,DD)，因为在单区域抓包中，主要捕获到区域内的报文，包括网络、路由器和链路状态信息。而在多区域抓包中，会捕获到 ABR（区域边界路由器） 之间交换的报文，这些报文包含了不同区域之间的路由信息和汇总信息。
开启RTC的g0/0/0端口 ，对RTC的g0/0/0端口进行抓包
可以注意到一点，多区域ospf响应要比单区域慢一些，这是因为 多区域OSPF 使用了洪泛（flooding）机制来传播 LSA 更新信息，每个路由器都需要将 LSA 发送给它的邻居，然后邻居再将其转发给它们的邻居，以此类推，直到 LSA 到达整个网络。
以下是RTB的g0/0/0端口的抓包，这里可以比较清楚的看到ospf的更新机制
1.DR使用LSA包回复发生变化的路由器，并使用组播地址224.0.0.5向其他路由器发送LSU包泛洪，每一个收到泛洪的路由器使用LSA包回复DR。
注：如果一个路由器被连接到其他网络，它便转发LSU泛洪分组给这个网络的DR，DR再转发到这个网络中的其他路由器。
2.收到LSU更新包的路由器，更新自己的链路状态数据库（LSDB），并通过最短生成树算法计算出最短路径更新到路由表。
多区域特点
1.ospf多区域通过划分不同的区域，实现了对每个区域进行独立的配置和管理。
2.OSPF 多区域允许跨区域进行路由，通过主干区域将不同区域连接起来。这样可以实现更高效的路径选择和数据流转发。
3.如果某个区域发生故障，其他区域仍然可以正常工作，提高了整个网络的可用性和容错性。
如果佬们发现什么错误或者有抓包的更多细节，请不吝赐教，感谢佬们！！💝💝💝
