Monday, February 10, 2014

OSPF Virtual Link



Task 1
Ensure that R3 will have connectivity VLAN 12 subnet in case Frame-Relay connection is down.

Questions
Try to answer the following questions:
  1. How does traffic flow between areas in multiarea OSPF design?
  2. What area two common methods available to patch a partitioned Area 0 or connect a disconnected area to Area 0?
Lab Solution

Solution configuration can be accessed below; solution contains task 1 and task 2 (if you want to save it, click the link, then go to File-->Download):
https://drive.google.com/file/d/0BwE5C95tpjZOeUhoX0ZNUTV5Ykk/edit?usp=sharing

Task 1
Ensure that R3 will have connectivity VLAN 12 subnet in case Frame-Relay connection is down.

R1 Config:
!
router ospf 1
 area 13 virtual-link 10.0.3.3
!

R3 Config:
!
router ospf 1
 area 13 virtual-link 10.0.1.1
!

Pic. 2 - OSPF Virtual Link Between R1 and R3.


Pic. 3 - Virtual Link.



Study Drill

 OSPF assumes that connectivity between areas will need to through backbone area. In case backbone area (area 0) is partitioned or an area lost direct connection to area 0, OSPF virtual-link or GRE tunnel can be used to enable connectivity.