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How is OSPF metric calculated?
A. OSPF uses a reference bandwidth of 100 Mbps for cost calculation. The formula to calculate the cost is reference bandwidth divided by interface bandwidth. For example, in the case of Ethernet, it is 100 Mbps / 10 Mbps = 10.
What is metric in OSPF?
The OSPF metric for a route is the sum of the interface costs for all outgoing interfaces in the route. By default, a router’s OSPF interface cost is actually derived from the interface bandwidth: The faster the bandwidth, the lower the cost. OSPF considers the costs of the outgoing interfaces (only) in each route.
Which of the following is the metric used for OSPF?
Open Shortest Path First (OSPF) uses “Cost” as the value of metric and uses a Reference Bandwidth of 100 Mbps for cost calculation.
What algorithm does OSPF use?
the shortest path first (SPF)
OSPF uses the shortest path first (SPF) algorithm to determine routes that should be added to the routing table. OSPF routers maintain a map of the internetwork called the link state database.
Is OSPF a layer 3 protocol?
Layer 3 Dynamic Routing Protocols Many dynamic routing protocols are being used, but most organizations rely on two for their internal routing of IP traffic: OSPF and Cisco Systems’ proprietary Enhanced Interior Gateway Routing Protocol (EIGRP).
How is the cost of OSPF metric calculated?
Open Shortest Path First (OSPF) uses “Cost” as the value of metric and uses a Reference Bandwidth of 100 Mbps for cost calculation. The formula to calculate the cost is Reference Bandwidth divided by interface bandwidth.
What is the OSPF metric for 10 Mbps Ethernet?
For example, in the case of 10 Mbps Ethernet , OSPF Metric Cost value is 100 Mbps / 10 Mbps = 10. The default Reference Bandwidth of OSPF is 100 Mbps and the default OSPF cost formula doesn’t differentiate between interfaces with bandwidth faster than 100 Mbps.
What is the default bandwidth of OSPF interface?
If bandwidth is set through this command, OSPF will use it. If bandwidth is not set, it will use interface’s default bandwidth. When we enable an interface, router automatically assign a bandwidth value to it based on its type. For example serial interface has a default bandwidth value of 1544k.
What is the OSPF metric for Christchurch to Wellington?
Here, the cost of Ethernet interfaces between Christchurch and Auckland/Wellington appears to be 10 (are the interfaces running on 10Mbps?), plus the cost of the link from Auckland/Wellington to the directly connected 172.16.50.0/24 is 781 (remember, the default bandwidth for slow serial interfaces is 128 Kbps). Hence, 10+781 = 791.