What is OSPF and what are its characteristics?

The OSPF (Open Shortest Path First) protocol is one of a family of IP Routing protocols, and is an Interior Gateway Protocol (IGP) for the Internet, used to distribute IP routing information throughout a single Autonomous System (AS) in an IP network.

What are three characteristics of OSPF?

What are three characteristics of the OSPF routing protocol? (Choose three.) OSPF bases link cost on bandwidth to determine the best route. OSPF is a distance vector type of protocol. OSPF uses DUAL algorithm for route computation.

What are the features in OSPF in networking?

It is based on a link-state routing algorithm in which each router contains the information of every domain, and based on this information, it determines the shortest path. The goal of routing is to learn routes. The OSPF achieves by learning about every router and subnet within the entire network.

What are the 5 types of OSPF packets?

Packet types for OSPF
  • Hello packet. This packet is sent by the OMPROUTED server to discover OSPF neighbor routers and to establish bidirectional communications with them. …
  • Database description packet. …
  • Link-state update packet. …
  • Link-state request packet. …
  • Link-state acknowledgment packet.

What is the main purpose of OSPF?

Open Shortest Path First (OSPF) is a routing protocol for Internet Protocol (IP) networks. It uses a link state routing (LSR) algorithm and falls into the group of interior gateway protocols (IGPs), operating within a single autonomous system (AS).

What are the 7 stages of OSPF?

Following are the OSPF States we’ll be examining:
  • Down state.
  • Attempt state.
  • Init state.
  • 2-Way state.
  • Exstart state.
  • Exchange state.
  • Loading state.
  • Full state.

What are the components of OSPF?

OSPF is a link-state protocol based on the open standard. At a high level, OSPF operation consists of three main elements: neighbor discovery, link-state information exchange, and best-path calculation.

What is OSPF also known as?

Open Shortest Path First (OSPF) is classified as an Interior Gateway Protocol (IGP). This means that it distributes routing information between routers belonging to a single autonomous system (AS), a group of routers all using a common routing protocol.

What are the components of OSPF?

OSPF is a link-state protocol based on the open standard. At a high level, OSPF operation consists of three main elements: neighbor discovery, link-state information exchange, and best-path calculation.

How many tables are there in OSPF?

three separate
The OSPF process builds and maintains three separate tables: • A neighbor table – contains a list of all neighboring routers. A topology table – contains a list of all possible routes to all known networks within an area. A routing table – contains the best route for each known network.

What is difference between RIP and OSPF?

Unlike RIP, which needs routers to broadcast the whole routing table to neighbors every 30 seconds, OSPF only sends the parts of the routing table that have changed and only when a change has occurred.

What are OSPF LSA types?

OSPF LSA Types Explained
  • LSA Type 1: Router LSA.
  • LSA Type 2: Network LSA.
  • LSA Type 3: Summary LSA.
  • LSA Type 4: Summary ASBR LSA.
  • LSA Type 5: Autonomous system external LSA.
  • LSA Type 6: Multicast OSPF LSA.
  • LSA Type 7: Not-so-stubby area LSA.
  • LSA Type 8: External attribute LSA for BGP.

Which layer is OSPF?

OSPF and BGP belong to the Application Layer.

What port does OSPF use?

port 89
OSPF uses an port at the IP layer ie. port 89 so it does not use TCP for reliable delivery. So to ensure reliable delivery of LSAs OSPF uses implicit and explicit acknowledgement of transmitted LSAs.

How many routes can OSPF handle?

We very often see customers running OSPF in topologies way more complex than this and carrying between 4000 and 6000 routes (without any kind of summarization) without too many issues. In your case, you have a couple of factors playing for you.

What are the 7 stages of OSPF?

Following are the OSPF States we’ll be examining:
  • Down state.
  • Attempt state.
  • Init state.
  • 2-Way state.
  • Exstart state.
  • Exchange state.
  • Loading state.
  • Full state.

How many states are in OSPF?

The states are Down, Attempt, Init, 2-Way, Exstart, Exchange, Loading, and Full.

What is OSPF also known AS?

Open Shortest Path First (OSPF) is classified as an Interior Gateway Protocol (IGP). This means that it distributes routing information between routers belonging to a single autonomous system (AS), a group of routers all using a common routing protocol.

What is OSPF example?

A simple two-router OSPF network

Here’s an example of a network configuration that creates a very simple OSPF network between two Cisco routers. The routers are placed in area 0 and an OSPF point-to-point link is configured between them. R1 will announce the 1.1. 1.1/32 route and R2 will announce 2.2.

What algorithm does OSPF use?

shortest path first (SPF) algorithm
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.

Why is OSPF stuck in two way states?

If you are seeing neighborship stuck in 2-Way state, there could be two possibilities: a) In network segments with multiple OSPF routers, two routers are chosen as DR and BDR respectively based on their priority or Router ID. All other OSPF routers are supposed to form adjacency with DR and BDRs.