Configuring Ospf Virtual Link - Huawei Quidway S3900 Series Operation Manual

Operation Manual – Routing Protocol
Quidway S3900 Series Ethernet Switches-Release 1510
[Switch C-ospf-1] area 0
[Switch C-ospf-1-area-0.0.0.0] network 196.1.1.0 0.0.0.255
# Configure Switch D.
<Switch D> system-view
[Switch D] interface Vlan-interface 1
[Switch D-Vlan-interface1] ip address 196.1.1.4 255.255.255.0
[Switch D] router id 4.4.4.4
[Switch D] ospf
[Switch D-ospf-1] area 0
[Switch D-ospf-1-area-0.0.0.0] network 196.1.1.0 0.0.0.255
On Switch A, run the display ospf peer command to display its OSPF peers. Note
that Switch A has three peers.
The state of each peer is full, which means that adjacency is established between
Switch A and each peer. Switch A and Switch C must establish adjacencies with all
the switches on the network so that they can serve as the DR and BDR respectively
on the network. Switch A is DR, while Switch C is BDR on the network. All the other
neighbors are DR others (This means that they are neither DRs nor BDRs).
# Change the priority of Switch B to 200.
<Switch B> system-view
[Switch B] interface Vlan-interface 2000
[Switch B-Vlan-interface2000] ospf dr-priority 200
On Switch A, run the display ospf peer command to display its OSPF peers. Note
that the priority of Switch B has been changed to 200, but it is still not the DR.
The DR is changed only when the current DR turn offline. Shut down Switch A, and
run the display ospf peer command on Switch D to display its peers. Note that the
original BDR (Switch C) becomes the DR and Switch B becomes BDR now.
If all Ethernet Switches on the network are removed from and then added to the
network again, Switch B will be elected as the DR (with a priority of 200), and Switch A
will be the BDR (with a priority of 100). Shutting down and restarting all of the switches
will bring about a new round of DR/BDR selection.

4.9.2 Configuring OSPF Virtual Link

I. Network requirements
As shown in Figure 4-4, Area 2 and Area 0 are not directly interconnected. It is
required to use Area 1 as a transition area for interconnecting Area 2 and Area 0.
Correctly configure a virtual link between Switch B and Switch C in Area 1.
Huawei Technologies Proprietary
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Chapter 4 OSPF Configuration