Configuring Single-Area OSPF network Lab Initial StateWe use the topology shown in the diagram below. Seven network devices are located at three locations: the data center, large, and small branches.…

OSPF Passive Interface Why do we need an OSPF passive interface?A router often does not need to form neighbor relationships on every interface. For example, the router in the diagram below…

GRE & DM-VPN History of DM-VPN The history of DMVPN (Dynamic Multipoint VPN) is closely tied to the evolution of enterprise networking and the need for scalable, secure, and cost-effective…

Ethernet Connector RJ45 Connector What is “RJ45”Do you know the meaning of “RJ45”? Let me explain it.“RJ” is the abbreviation of “registered jack”, which originally means a standardized telecoms network interface…

Transmission Media Transmission Media in Computer Network IntroductionThe modern global environment is constantly evolving. Data Communication and networking technologies have revolutionized many aspects of modern life. They now depend on…

IT Courses What is CompTIA+ What is CompTIA+CompTIA+ refers to a group of IT certifications offered by CompTIA. These certifications are vendor-neutral, meaning they are not limited to one company…

OSPF Commnds Check OSPF configuration, status, and neighbors on Cisco routersshow ip ospf neighbor Displays OSPF neighbors and their current state, including IP addresses, interface, state, and area.Show OSPF Interfaceshow ip…

OSPF DR and BDR OSPF DR and BDRThis lesson demonstrates the OSPF concept of a Designated Router (DR) and a Backup Designated router (BDR). We discuss why we need DR…

How does OSPF work The last lesson introduced the most fundamental OSPF terms, such as LSA, LSDB, SPF, Areas, Cost, and Neighbors. In this lesson, we continue introducing new concepts…

IP Address 1. What is IP AddressAn IP address (Internet Protocol Address) is a unique numerical identifier assigned to every device connected to a network that uses the Internet Protocol…