{"id":5202,"date":"2024-09-09T06:38:13","date_gmt":"2024-09-09T11:38:13","guid":{"rendered":"http:\/\/109.199.106.156\/~indeni\/wp\/?p=1661"},"modified":"2024-09-09T06:38:13","modified_gmt":"2024-09-09T11:38:13","slug":"ospf-virtual-link-configuration","status":"publish","type":"post","link":"https:\/\/ddi.mohflo.net\/index.php\/2024\/09\/09\/ospf-virtual-link-configuration\/","title":{"rendered":"OSPF Virtual Link Configuration"},"content":{"rendered":"

\"Data<\/a> <\/p>\n

We all know about OSPF (Open Shortest Path First) protocol\u2013a fast link state protocol that is a go-to IGP (Interior Gateway Protocol) routing in large enterprises. It is also an open source protocol.<\/p>\n

OSPF calculates shortest path for each route using Dijkstra\u2019s algorithm<\/a>. It uses area 0 as a backbone and every other area must be directly connected to it. There are cases in which we need to circumvent this rule and connect the OSPF area through the transit area<\/em> to area 0. This occurs, for example, when the OSPF area has no direct connection to the backbone.<\/p>\n

The configuration solution is an OSPF virtual link.<\/p>\n

Let\u2019s look at the following example:<\/h2>\n

R3 has no physical connection to the backbone, which means it cannot get routing updates. We will create an OSPF virtual link through R1 and R2 to connect R3 to area 0 by going through transit area AS100.<\/p>\n

OSPF Configuration Virtual Link example:<\/p>\n

Follow these steps to configure an OSPF virtual link:<\/h4>\n