localtime选择00:00值不回显_配置OSPF的DR选择示例

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组网需求

如图1所示，部署OSPF协议的网络中有五台交换机，其中Switch作为二层交换机连接其他运行OSPF协议的四台交换机。由于之前四台设备之间缺省选举的DR不符合网络需求，现在需要让SwitchA被选举为DR来和OSPF网络其他设备交互LSA信息，而SwitchC则作为SwitchA的备份。而SwitchB由于其他业务需要，只能让它通过DR来与OSPF网络其他设备交互LSA信息。

图1 配置OSPF的DR选择组网图

配置思路

采用如下的思路配置OSPF的DR选择：

1. 在各交换机上配置OSPF的基本功能，查看四台交换机之间缺省的DR的选举情况。

2. 配置SwitchA对应接口的DR优先级为100，SwitchB对应接口的DR优先级为0，SwitchC对应接口的DR优先级为2，使得SwitchA被选举为DR，SwitchC被选举为BDR，SwitchB永远无法成为DR或BDR，而SwitchD采用缺省DR优先级，维持原状不变。

操作步骤

1. 配置各接口所属的VLAN

# 配置SwitchA。Switch、SwitchB、SwitchC和SwitchD的配置与SwitchA类似。

<HUAWEI> system-view
[HUAWEI] sysname SwitchA
[SwitchA] vlan batch 10
[SwitchA] interface gigabitethernet 0/0/1
[SwitchA-GigabitEthernet0/0/1] port link-type trunk
[SwitchA-GigabitEthernet0/0/1] port trunk allow-pass vlan 10
[SwitchA-GigabitEthernet0/0/1] quit

2. 配置各VLANIF接口的IP地址

# 配置SwitchA。SwitchB、SwitchC和SwitchD的配置与SwitchA类似。

[SwitchA] interface vlanif 10
[SwitchA-Vlanif10] ip address 192.168.1.1 24
[SwitchA-Vlanif10] quit

3. 配置OSPF基本功能

# 配置SwitchA。

[SwitchA] ospf 1 router-id 10.1.1.1
[SwitchA-ospf-1] area 0
[SwitchA-ospf-1-area-0.0.0.0] network 192.168.1.0 0.0.0.255
[SwitchA-ospf-1-area-0.0.0.0] quit
[SwitchA-ospf-1] quit

# 配置SwitchB。

[SwitchB] ospf 1 router-id 10.2.2.2
[SwitchB-ospf-1] area 0
[SwitchB-ospf-1-area-0.0.0.0] network 192.168.1.0 0.0.0.255
[SwitchB-ospf-1-area-0.0.0.0] quit
[SwitchB-ospf-1] quit

# 配置SwitchC。

[SwitchC] ospf 1 router-id 10.3.3.3
[SwitchC-ospf-1] area 0
[SwitchC-ospf-1-area-0.0.0.0] network 192.168.1.0 0.0.0.255
[SwitchC-ospf-1-area-0.0.0.0] quit
[SwitchC-ospf-1] quit

# 配置SwitchD。

[SwitchD] ospf 1 router-id 10.4.4.4
[SwitchD-ospf-1] area 0
[SwitchD-ospf-1-area-0.0.0.0] network 192.168.1.0 0.0.0.255
[SwitchD-ospf-1-area-0.0.0.0] quit
[SwitchD-ospf-1] quit
[SwitchD] quit

# SwitchA上查看OSPF邻居的信息。

[SwitchA] display ospf peerOSPF Process 1 with Router ID 10.1.1.1NeighborsArea 0.0.0.0 interface 192.168.1.1(Vlanif10)'s neighborsRouter ID: 10.2.2.2      Address: 192.168.1.2
State: 2-Way  Mode:Nbr is  Master  Priority: 1
DR: 192.168.1.4  BDR: 192.168.1.3  MTU: 0Dead timer due in 32  secRetrans timer interval: 5Neighbor is up for 00:04:21Authentication Sequence: [ 0 ]Router ID: 10.3.3.3      Address: 192.168.1.3
State: Full  Mode:Nbr is  Master  Priority: 1
DR: 192.168.1.4  BDR: 192.168.1.3  MTU: 0Dead timer due in 37  secRetrans timer interval: 5Neighbor is up for 00:04:06Authentication Sequence: [ 0 ]Router ID: 10.4.4.4      Address: 192.168.1.4
State: Full  Mode:Nbr is  Master  Priority: 1
DR: 192.168.1.4  BDR: 192.168.1.3  MTU: 0Dead timer due in 37  secRetrans timer interval: 5Neighbor is up for 00:03:53Authentication Sequence: [ 0 ]

从以上回显中可以看到在缺省情况下SwitchD为DR，SwitchC为BDR。这是因为当DR优先级相同时，Router-ID高的被选举为DR。

4. 配置交换机接口上的DR优先级

# 配置SwitchA。

[SwitchA] interface vlanif 10
[SwitchA-Vlanif10] ospf dr-priority 100
[SwitchA-Vlanif10] quit
[SwitchA] quit

# 配置SwitchB。

[SwitchB] interface vlanif 10
[SwitchB-Vlanif10] ospf dr-priority 0
[SwitchB-Vlanif10] quit
[SwitchB] quit

# 配置SwitchC。

[SwitchC] interface vlanif 10
[SwitchC-Vlanif10] ospf dr-priority 2
[SwitchC-Vlanif10] quit
[SwitchC] quit

# 在SwitchD上查看OSPF邻居的信息。

<SwitchD> display ospf peerOSPF Process 1 with Router ID 10.4.4.4NeighborsArea 0.0.0.0 interface 192.168.1.4(Vlanif10)'s neighborsRouter ID: 10.1.1.1      Address: 192.168.1.1State: Full  Mode:Nbr is  Slave  Priority: 100
DR: 192.168.1.4  BDR: 192.168.1.3  MTU: 0Dead timer due in 31  secRetrans timer interval: 5Neighbor is up for 00:11:17Authentication Sequence: [ 0 ]Router ID: 10.2.2.2      Address: 192.168.1.2State: Full  Mode:Nbr is  Slave  Priority: 0
DR: 192.168.1.4  BDR: 192.168.1.3  MTU: 0Dead timer due in 35  secRetrans timer interval: 5Neighbor is up for 00:11:19Authentication Sequence: [ 0 ]Router ID: 10.3.3.3      Address: 192.168.1.3State: Full  Mode:Nbr is  Slave  Priority: 2
DR: 192.168.1.4  BDR: 192.168.1.3  MTU: 0Dead timer due in 33  secRetrans timer interval: 5Neighbor is up for 00:11:15Authentication Sequence: [ 0 ]

通过以上回显信息发现四台交换机之间DR的选举情况并没有改变。这是因为如果DR、BDR已经选择完毕，当一台新设备加入后，即使它的DR优先级值最大，也不会立即成为该网段中的DR，只有重启OSPF进程之后才会重新选举DR和BDR。

5. 重启OSPF进程

# 在各交换机的用户视图下，同时执行命令reset ospf 1 process，以重启OSPF进程。同时重启OSPF进程是为了让四台交换机都参与DR和BDR的选举过程。

# 重启SwitchA

<SwitchA> reset ospf 1 process

# 重启SwitchB

<SwitchB> reset ospf 1 process

# 重启SwitchC

<SwitchC> reset ospf 1 process

# 重启SwitchD

<SwitchD> reset ospf 1 process

6. 验证配置结果

# 在SwitchD上查看OSPF邻居信息。

<SwitchD> display ospf peerOSPF Process 1 with Router ID 10.4.4.4NeighborsArea 0.0.0.0 interface 192.168.1.4(Vlanif10)'s neighborsRouter ID: 10.1.1.1      Address: 192.168.1.1
State: Full  Mode:Nbr is  Slave  Priority: 100
DR: 192.168.1.1  BDR: 192.168.1.3  MTU: 0Dead timer due in 35  secRetrans timer interval: 5Neighbor is up for 00:07:19Authentication Sequence: [ 0 ]Router ID: 10.2.2.2      Address: 192.168.1.2
State: 2-Way  Mode:Nbr is  Master  Priority: 0
DR: 192.168.1.1  BDR: 192.168.1.3  MTU: 0Dead timer due in 35  secRetrans timer interval: 5Neighbor is up for 00:07:19Authentication Sequence: [ 0 ]Router ID: 10.3.3.3      Address: 192.168.1.3
State: Full  Mode:Nbr is  Slave  Priority: 2
DR: 192.168.1.1  BDR: 192.168.1.3  MTU: 0Dead timer due in 37  secRetrans timer interval: 5Neighbor is up for 00:07:17Authentication Sequence: [ 0 ]

从以上回显中可以看到SwitchA被选举为DR，SwitchC为BDR。而SwitchD与SwitchB之间的邻居状态为2-Way，这说明两者既不是DR，也不是BDR，即它们之间不需要交换LSA信息。

配置文件

Switch的配置文件

#
sysname Switch
#
vlan batch 10
#
interface GigabitEthernet0/0/1port link-type trunkport trunk allow-pass vlan 10
#
interface GigabitEthernet0/0/2port link-type trunkport trunk allow-pass vlan 10
#
interface GigabitEthernet0/0/3port link-type trunkport trunk allow-pass vlan 10
#
interface GigabitEthernet0/0/4port link-type trunkport trunk allow-pass vlan 10
#
return

SwitchA的配置文件

#
sysname SwitchA
#
vlan batch 10
#
interface Vlanif10ip address 192.168.1.1 255.255.255.0ospf dr-priority 100
#
interface GigabitEthernet0/0/1port link-type trunkport trunk allow-pass vlan 10
#
ospf 1 router-id 10.1.1.1area 0.0.0.0network 192.168.1.0 0.0.0.255
#
return

SwitchB的配置文件

#
sysname SwitchB
#
vlan batch 10
#
interface Vlanif10ip address 192.168.1.2 255.255.255.0ospf dr-priority 0
#
interface GigabitEthernet0/0/1port link-type trunkport trunk allow-pass vlan 10
#
ospf 1 router-id 10.2.2.2area 0.0.0.0network 192.168.1.0 0.0.0.255
#
return

SwitchC的配置文件

#
sysname SwitchC
#
vlan batch 10
#
interface Vlanif10ip address 192.168.1.3 255.255.255.0ospf dr-priority 2
#
interface GigabitEthernet0/0/1port link-type trunkport trunk allow-pass vlan 10
#
ospf 1 router-id 10.3.3.3area 0.0.0.0network 192.168.1.0 0.0.0.255
#
return

SwitchD的配置文件

#
sysname SwitchD
#
vlan batch 10
#
interface Vlanif10ip address 192.168.1.4 255.255.255.0
#
interface GigabitEthernet0/0/1port link-type trunkport trunk allow-pass vlan 10
#
ospf 1 router-id 10.4.4.4area 0.0.0.0network 192.168.1.0 0.0.0.255
#
return