【OSPF协议】华为OSPF多区域配置

拓扑结构

实现功能

步骤

1. 基础配置

以R3为例：

#
sysname R3
#
interface LoopBack0
ip address 10.3.3.3 255.255.255.255
#
interface LoopBack1
ip address 10.3.0.1 255.255.255.0
#
interface LoopBack2
ip address 10.3.1.1 255.255.255.0
#
interface GigabitEthernet0/0/0
ip address 10.0.123.3 255.255.255.0

[R3]display ip interface brief
*down: administratively down
^down: standby
(l): loopback
(s): spoofing
The number of interface that is UP in Physical is 5
The number of interface that is DOWN in Physical is 2
The number of interface that is UP in Protocol is 5
The number of interface that is DOWN in Protocol is 2

Interface IP Address/Mask Physical Protocol
GigabitEthernet0/0/0 10.0.123.3/24 up up
GigabitEthernet0/0/1 unassigned down down
GigabitEthernet0/0/2 unassigned down down
LoopBack0 10.3.3.3/32 up up(s)
LoopBack1 10.3.0.1/24 up up(s)
LoopBack2 10.3.1.1/24 up up(s)
NULL0 unassigned up up(s)

2. 配置多区域OSPF

以R2配置为例；

• 在R2与R4互联接口上修改网络类型为P2P，加快邻接关系建立；

ospf 1 router-id 10.2.2.2
area 0.0.0.0
network 10.0.24.1 0.0.0.0
network 10.2.2.2 0.0.0.0
area 0.0.0.2
network 10.0.123.2 0.0.0.0

interface GigabitEthernet0/0/1
ip address 10.0.24.1 255.255.255.252
ospf network-type p2p

配置完成后R2和R4上的邻居关系

<R2>display ospf peer brief

OSPF Process 1 with Router ID 10.2.2.2
Peer Statistic Information
—————————————————————————-
Area Id Interface Neighbor id State
0.0.0.0 GigabitEthernet0/0/1 10.4.4.4 Full
0.0.0.2 GigabitEthernet0/0/0 10.1.1.1 Full
0.0.0.2 GigabitEthernet0/0/0 10.3.3.3 Full
—————————————————————————-

<R4>display ospf peer brief

OSPF Process 1 with Router ID 10.4.4.4
Peer Statistic Information
—————————————————————————-
Area Id Interface Neighbor id State
0.0.0.0 GigabitEthernet0/0/0 10.2.2.2 Full
0.0.0.1 GigabitEthernet0/0/1 10.5.5.5 Full
—————————————————————————-

配置完成后R2和R4上的LSDB

R2和R4作为ABR维护两个区域的LSDB

<R2>display ospf lsdb

OSPF Process 1 with Router ID 10.2.2.2
Link State Database

Area: 0.0.0.0
Type LinkState ID AdvRouter Age Len Sequence Metric
Router 10.2.2.2 10.2.2.2 1582 60 8000000C 0
Router 10.4.4.4 10.4.4.4 1583 60 8000000C 0
Sum-Net 10.3.1.0 10.2.2.2 220 28 80000001 1
Sum-Net 10.3.0.0 10.2.2.2 226 28 80000001 1
Sum-Net 10.5.1.0 10.4.4.4 137 28 80000001 1
Sum-Net 10.5.0.0 10.4.4.4 147 28 80000001 1
Sum-Net 10.5.5.5 10.4.4.4 1461 28 80000001 1
Sum-Net 10.1.1.1 10.2.2.2 1362 28 80000001 1
Sum-Net 10.0.45.0 10.4.4.4 1629 28 80000001 1
Sum-Net 10.0.123.0 10.2.2.2 1733 28 80000001 1
Sum-Net 10.3.3.3 10.2.2.2 1296 28 80000001 1

Area: 0.0.0.2
Type LinkState ID AdvRouter Age Len Sequence Metric
Router 10.3.3.3 10.3.3.3 182 72 8000000E 0
Router 10.2.2.2 10.2.2.2 668 60 8000000F 1
Router 10.1.1.1 10.1.1.1 1303 48 80000006 0
Network 10.0.123.2 10.2.2.2 1296 36 80000004 0
Sum-Net 10.0.24.0 10.2.2.2 1714 28 80000001 1
Sum-Net 10.5.1.0 10.2.2.2 136 28 80000001 2
Sum-Net 10.5.0.0 10.2.2.2 146 28 80000001 2
Sum-Net 10.4.4.4 10.2.2.2 1582 28 80000001 1
Sum-Net 10.5.5.5 10.2.2.2 1460 28 80000001 2
Sum-Net 10.0.45.0 10.2.2.2 1582 28 80000001 2
Sum-Net 10.2.2.2 10.2.2.2 1733 28 80000001 0

<R4>display ospf lsdb

OSPF Process 1 with Router ID 10.4.4.4
Link State Database

Area: 0.0.0.0
Type LinkState ID AdvRouter Age Len Sequence Metric
Router 10.2.2.2 10.2.2.2 1626 60 8000000C 0
Router 10.4.4.4 10.4.4.4 1625 60 8000000C 0
Sum-Net 10.3.1.0 10.2.2.2 264 28 80000001 1
Sum-Net 10.3.0.0 10.2.2.2 270 28 80000001 1
Sum-Net 10.5.1.0 10.4.4.4 178 28 80000001 1
Sum-Net 10.5.0.0 10.4.4.4 189 28 80000001 1
Sum-Net 10.5.5.5 10.4.4.4 1502 28 80000001 1
Sum-Net 10.1.1.1 10.2.2.2 1406 28 80000001 1
Sum-Net 10.0.45.0 10.4.4.4 1671 28 80000001 1
Sum-Net 10.0.123.0 10.2.2.2 1777 28 80000001 1
Sum-Net 10.3.3.3 10.2.2.2 1339 28 80000001 1

Area: 0.0.0.1
Type LinkState ID AdvRouter Age Len Sequence Metric
Router 10.5.5.5 10.5.5.5 136 72 80000008 0
Router 10.4.4.4 10.4.4.4 1500 36 80000005 1
Network 10.0.45.1 10.4.4.4 1500 32 80000002 0
Sum-Net 10.3.1.0 10.4.4.4 263 28 80000001 2
Sum-Net 10.3.0.0 10.4.4.4 269 28 80000001 2
Sum-Net 10.0.24.0 10.4.4.4 1671 28 80000001 1
Sum-Net 10.4.4.4 10.4.4.4 1671 28 80000001 0
Sum-Net 10.1.1.1 10.4.4.4 1405 28 80000001 2
Sum-Net 10.2.0.0 10.4.4.4 757 28 80000001 1
Sum-Net 10.0.123.0 10.4.4.4 1624 28 80000001 2
Sum-Net 10.3.3.3 10.4.4.4 1339 28 80000001 2

3. 配置路由汇总

3.1 区域间路由汇总

区域间路由汇总减少区域间的路由条目，也减少了路由震荡的发生。

在R4区域1（要汇总那个区域的路由就在那个区域执行汇总）对R5的L1和L2的路由进行汇聚。

#
ospf 1 router-id 10.4.4.4
area 0.0.0.0
network 10.0.24.2 0.0.0.0
network 10.4.4.4 0.0.0.0
area 0.0.0.1
abr-summary 10.5.0.0 255.255.254.0
network 10.0.45.1 0.0.0.0

汇总后，R4作为ABR再向区域0发布路由时只发布汇总后的路由

[R4-ospf-1]display ospf lsdb

OSPF Process 1 with Router ID 10.4.4.4
Link State Database

Area: 0.0.0.0
Type LinkState ID AdvRouter Age Len Sequence Metric
Sum-Net 10.5.0.0 10.4.4.4 92 28 80000002 1
Sum-Net 10.5.5.5 10.4.4.4 22 28 80000002 1

在R2上区域2中对R3的L1和L2接口路由进行汇总

ospf 1 router-id 10.2.2.2
area 0.0.0.0
network 10.0.24.1 0.0.0.0
network 10.2.2.2 0.0.0.0
area 0.0.0.2
abr-summary 10.2.0.0 255.255.254.0
network 10.0.123.2 0.0.0.0

汇总后R2在向区域0发布汇总后的路由

[R2]display ospf lsdb

OSPF Process 1 with Router ID 10.2.2.2
Link State Database

Area: 0.0.0.0
Type LinkState ID AdvRouter Age Len Sequence Metric
Sum-Net 10.3.0.0 10.2.2.2 1226 28 80000001 1

3.2 区域外路由汇总

在R2上将L1和L2的路由引入到OSPF（为了避免引入其他直连路由影响观察，这里做了ip前缀过滤）

ospf 1 router-id 10.2.2.2
filter-policy ip-prefix 1 export
import-route direct
area 0.0.0.0
network 10.0.24.1 0.0.0.0
network 10.2.2.2 0.0.0.0
area 0.0.0.2
abr-summary 10.2.0.0 255.255.254.0
network 10.0.123.2 0.0.0.0
#
ip ip-prefix 1 index 10 permit 10.2.0.0 24
ip ip-prefix 1 index 20 permit 10.2.1.0 24

引入后R4收到2条5类LSA

R5收到5类LSA和R4通告的4类LSA

在R2上进行外部路由汇聚

ospf 1 router-id 10.2.2.2
asbr-summary 10.2.0.0 255.255.254.0
filter-policy ip-prefix 1 export
import-route direct
area 0.0.0.0
network 10.0.24.1 0.0.0.0
network 10.2.2.2 0.0.0.0
area 0.0.0.2
abr-summary 10.2.0.0 255.255.254.0
network 10.0.123.2 0.0.0.0

R5此时的OSPF路由表和IP路由表

4、修改OSPF参考带宽值

以R2为例

[!WARNING]
OSPF域内的所有路由器参考贷款值必须一致

ospf 1 router-id 10.2.2.2
bandwidth-reference 10000

5、在OSPF引入缺省路由

在R1的L0接口模拟接入互联网

]ip route-static 0.0.0.0 0.0.0.0 LoopBack 0

将缺省路由引入到OSPF，指定外部类型为Type 1

ospf 1 router-id 10.1.1.1
default-route-advertise always type 1

[!IMPORTANT]
default-route-advertise always type 1

• always 无论本机是否存在激活的非本OSPF进程缺省路由，都会产生并发布一个描述缺省路由的LSA。
• type 指定外部路由类型（缺省为2）

在其他路由器查看引入的默认路由，以R2为例，因为引入Type=1，因此会计算Cost

6、修改OSPF中路由优先级

以R3为例，修改OSPF协议区域内、区域间的路由优先级为20，修改外部路由优先级为50

ospf 1 router-id 10.3.3.3
preference 20
preference ase 50

完整配置

R2为例

<R2>display current-configuration
[V200R003C00]
#
sysname R2
#
snmp-agent local-engineid 800007DB03000000000000
snmp-agent
#
clock timezone China-Standard-Time minus 08:00:00
#
portal local-server load portalpage.zip
#
drop illegal-mac alarm
#
router id 10.2.2.2
#
set cpu-usage threshold 80 restore 75
#
aaa
authentication-scheme default
authorization-scheme default
accounting-scheme default
domain default
domain default_admin
local-user admin password cipher %$%$K8m.Nt84DZ}e#<0`8bmE3Uw}%$%$
local-user admin service-type http
#
firewall zone Local
priority 15
#
interface GigabitEthernet0/0/0
ip address 10.0.123.2 255.255.255.0
#
interface GigabitEthernet0/0/1
ip address 10.0.24.1 255.255.255.252
ospf network-type p2p
#
interface GigabitEthernet0/0/2
#
interface NULL0
#
interface LoopBack0
ip address 10.2.2.2 255.255.255.255
#
interface LoopBack1
ip address 10.2.0.1 255.255.255.0
#
interface LoopBack2
ip address 10.2.1.1 255.255.255.0
#
ospf 1 router-id 10.2.2.2
asbr-summary 10.2.0.0 255.255.254.0
filter-policy ip-prefix 1 export
import-route direct
bandwidth-reference 10000
area 0.0.0.0
network 10.0.24.1 0.0.0.0
network 10.2.2.2 0.0.0.0
area 0.0.0.2
abr-summary 10.2.0.0 255.255.254.0
network 10.0.123.2 0.0.0.0
#
ip ip-prefix 1 index 10 permit 10.2.0.0 24
ip ip-prefix 1 index 20 permit 10.2.1.0 24
#
user-interface con 0
authentication-mode password
user-interface vty 0 4
user-interface vty 16 20
#
wlan ac
#
return

延伸

外部路由的两种类型

Type-1 可信度高，开销计算= AS外部开销 + AS内部开销

Type-2 可信度低，AS外部开销远大于内部开销，开销值计算= AS外部开销