What is Open Shortest Path First protocol?
Open Shortest Path First (OSPF) is a link-state routing protocol that was developed for IP networks and is based on the Shortest Path First (SPF) algorithm. OSPF is an Interior Gateway Protocol (IGP).
Which type of routing protocol uses the shortest path first 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.
What are the benefits of Open Shortest Path First OSPF protocol?
OSPF supports/provides/advantages –
- Both IPv4 and IPv6 routed protocols.
- Load balancing with equal-cost routes for the same destination.
- VLSM and route summarization.
- Unlimited hop counts.
- Trigger updates for fast convergence.
- A loop-free topology using SPF algorithm.
- Run-on most routers.
- Classless protocol.
What is the default priority for Open Shortest Path First OSPF routers?
Router priority – It is an 8-bit value assigned to a router operating OSPF, used to elect DR and BDR in a broadcast network. Designated Router (DR) – It is elected to minimize the number of adjacencies formed. DR distributes the LSAs to all the other routers.
Is OSPF multicast?
OSPF uses multicast functions when interfaces are attached to broadcast networks, such as Ethernet. For all OSPF routers, these interfaces are joined to multicast address 224.0. 0.5.
Which multicast address does the OSPF Hello protocol use?
224.0.0.5
The multicast address that the OSPF Hello protocol uses is 224.0. 0.5.
What is meant by an OSPF Open Shortest Path First autonomous system?
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.
How does the OSPF work?
How OSPF Works? When it is configured, it listens to its neighbours in the networks, and it gathers all the link state data available. This data is then used to make a topology map that contains all available paths in the network. This database is saved for use, and we call it Link State Database.
How many LSA types are there?
LSA Type 8: OSPF External Attributes LSA (OSPFv2) / Link Local LSA (OSPFv3) LSA Type 9: OSPF Link Scope Opaque (OSPFv2) / Intra Area Prefix LSA (OSPFv3) LSA Type 10: OSPF Area Scope Opaque LSA. LSA Type 11:OSPF AS (Autonomous System) Scope Opaque LSA.
How multicast works in OSPF?
Multicasts are used a lot between routers so they can discover each other on an IP network. For example, an Open Shortest Path First (OSPF) router sends a “hello” packet to other OSPF routers on the network. The OSPF router must send this “hello” packet to an assigned multicast address, which is 224.0.
What is the routing protocol for IP multicast?
There is no standard routing protocol for IP multicast. This is because of the transmission radius and the number of receiving stations which have a significant influence on the required protocol architecture.
What is Protocol Independent Multicast (PIM)?
Protocol Independent Multicast (PIM) is a routing protocol family, which does not have its own means of generating routing tables. Therefore, PIM relies on information provided by the unicast routing protocols active in the network.
What multicast address does OpenOSPF use?
OSPF uses multicast address 224.0.0.5 for normal communication and 224.0.0.6 for update to designated router (DR)/Backup Designated Router (BDR). Router I’d – It is the highest active IP address present on the router. First, the highest loopback address is considered.
What is the difference between MOSPF and Protocol Independent Multicast?
MOSPF does not require an additional routing protocol to map out the multicast tree, since it uses OSPF routing for this purpose. Protocol Independent Multicast (PIM) is a routing protocol family, which does not have its own means of generating routing tables.