Author: Author: Richard Pateau

Hi today I am going to talk about FHRP (First Hop Redundancy Protocol), and the protocols within it such as VRRP (Virtual Router Redundancy Protocol), HSRP (Hot Standby Redundancy Protocol), and GLBP (Gateway Load Balancing Protocol). FHRP is a default gateway redundancy protocol that provides a backup for the main default gateway. In setups like…

Today I am going to talk about serial interfaces. Serial interfaces are a point-to-point connection that is mostly used for WAN links or connections. By WAN connections, I mean T1/E1 circuits, DSL (digital subscriber lines), or leased lines. This WAN connection is most commonly from an ISP to a customer. Serial interfaces function very differently…

Today I am going to talk about LSA types. As you probably already know, OSPF routers in the same area have a database (LSDB) full of LSAs. This LSDB serves as the network topology map from which routes are created. LSAs can also extend to inter-areas and certain LSAs are meant for the entire OSPF…

OSPF is a very versatile dynamic routing protocol, not only does it provide redundancy, fast convergence, scalability, automatic failover but it works with all types of network types as well. Today I am going to talk about broadcast and point-to-point OSPF networks and how they function.Broadcast- Broadcast OSPF network is one of the most common…

In order for OSPF to keep its topology current and up to date with any changes or failures, it has some important timers. Three timers I am going to talk about today are the hello interval timer, dead interval timer, and the retransmission timer.  Hello Timer- The hello timer is a timer that dictates how…

Today I am going to dive into OSPF router adjacency roles. In broadcast/non-broadcast multi-access network topologies, OSPF elects routers to maintain a certain role within the topology to provide redundancy, and make communication/updates more efficient. The roles that make OSPF broadcast network types run smoothly are the DR (Designated Router), BDR (Backup Designated Router), and…

Today I am going to talk about OSPF neighbor states and what goes on under the hood when a new OSPF topology first comes online. Before a link reaches a full state and the network is fully converged with a complete identical topology map. For broadcast and non-broadcast multi-access topologies, link neighbors must go through…

Today I am going to talk about the types of messages that can be sent when OSPF is enabled. Every message type is unique in its own way and allows OSPF to function as smoothly as it does. These message types each serve their purpose in their own way from discovering neighbors to providing reliability….