Contents
Why master slave election happens in OSPF?
Master/Slave – First of all the master/slave relation is determined, to decide who speaks first. This is determined by priority, with the router-id being used to break any potential tie. Next, the master sends a summary packet, also known as the database description (DBD), of the LSDB. The slave then sends theirs.
Which of the following OSPF network types must be statically configured for DR BDR election to occur?
NBMA- Neighbors
NBMA- Neighbors must be statically configured on one subnet for all routers, it acts like LAN environment with DR/BDR elections except broadcasts and multicast are not allowed.
Does OSPF use multicast?
Update destination address: OSPF uses multicast and unicast, rather than broadcast, for sending messages. The IPv4 multicast addresses used for OSPF are 224.0. 0.5 to send information to all OSPF routers and 224.0.
Why BDR is elected first?
According to the RFC, the BDR is actually elected first, followed by the DR. The RFC explains why: “The reason behind the election algorithm’s complexity is the desire for an orderly transition from Backup Designated Router to Designated Router, when the current Designated Router fails.
What are OSPF States?
When OSPF adjacency is formed, a router goes through several state changes before it becomes fully adjacent with its neighbor. Those states are defined in the OSPF RFC 2328. , section 10.1. The states are Down, Attempt, Init, 2-Way, Exstart, Exchange, Loading, and Full.
When does OSPF stop using the router ID?
After the router has been running OSPF and selected its router ID, it still uses this router ID if the interface whose IP address is used as the router ID is Down or disappears (for example, the undo interface loopback loopback-number command is run) or a larger interface IP address exists.
How to create OSPF neighbor states for routers?
OSPF Neighbor States 1 Introduction. When OSPF adjacency is formed, a router goes through several state changes before it becomes fully adjacent with its neighbor. 2 Prerequisites. There are no specific requirements for this document. 3 Down. This is the first OSPF neighbor state. 4 Attempt. 5 Init. 6 2-Way. 7 Exstart.
How is Dr elected in master / slave roles?
Be careful – the original question relates to the negotiation of Master/Slave roles for exchanging LSAs, not the election of a DR. The DR is elected based upon highest priority (0 – 255, 0 being disabled) then, in the case of a tie, the highest Router ID.
When does a router become a master or slave?
Good post, so basically the router with interface having a higher IPv4/v6 address (for that particular broadcast or point-to-point segment) would become the master (or the initiator) and would send Database description packets with initiating sequence numbers? 09-18-2017 06:14 AM 09-18-2017 06:14 AM