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What is OSPF flooding?
OSPF is a link-state protocol, in which routers reliably flood “Link State Advertisements” (LSAs), enabling each to build a consistent, global view of the routing topology.
Are router IDS unique to OSPF?
The router ID uniquely identifies a router within an OSPF domain. As explained in Configuring OSPF, OSPF uses the largest IP address configured on the interfaces as its router ID. If there are no loopback interfaces present, the highest IP address in the router is chosen.
What is OSPF router ID?
The OSPF Router ID is used to provide a unique identity to the OSPF Router. OSPF Router ID is an IPv4 address (32-bit binary number) assigned to each router running the OSPF protocol. If there is no Loopback Interfaces configured, the highest IP address on its active interfaces is selected as the OSPF Router ID.
What is the flooding scope of an OSPF router?
Router LSAs are originated by all OSPF routers. Type-1 LSA contains the Link State ID (which is represented by the RID) and all the different Router Link-States. The LSA may contain information about multiple links within the same area. The flooding scope of Type-1 LSA is a single area.
Where does the LSA ID come from in OSPF?
External LSAs are originated by Autonomous System Boundary Routers (ASBRs). Type-5 LSAs contains Link State ID (External Routes), the Network Mask, the Advertising Router ID (ASBR RID), The External Metric Type (E1 or E2) and the Forward Address.
What does the router ID on an OSPF packet mean?
All OSPF packets begin with a standard 24-octet header. Note that the header includes a Router ID field, which indicates the unique ID of the route originating the OSPF packet. Typically, OSPF packets carry Link-State Advertisements (LSAs), which describe all of the links or interfaces of the router, and the state of the links.
What are the RFCs for OSPF over demand circuit?
Not-so-stubby area (NSSA)—RFC 3101, which replaces and is backward compatible with RFC 1587. OSPF over demand circuit—RFC 1793. OSPF typically requires coordination among many internal routers: Area Border Routers (ABRs), which are routers connected to multiple areas, and Autonomous System Boundary Routers (ASBRs).