Contents
Can an OSPF router be ABR and Asbr at the same time?
These routers maintain a link-state database for each area to which they belong. Autonomous system boundary router (ASBR)—Routers that inject external link-state advertisements into the OSPF database. Note that a router can be an ABR, ASBR, and backbone router at the same time.
Which router becomes DR in OSPF?
router with the highest OSPF priority will become a DR. By default, all routers have a priority of 1. if there is a tie, a router with the highest router ID wins the election. The router with the second highest OSPF priority or router ID will become a BDR.
What is the use of NSSA in OSPF?
NSSA ASBR can generate a default only when it has a default route in its routing table. The default route must be known through non-OSPF protocol. NSSA ABR can generate a default route with or without a default route in its own routing table.
Why does OSPF uses designated router DR?
Within OSPF, the role of the Designated Router (DR) and a Backup Designated Router (BDR) is to act as a central point for exchanging of OSPF information between multiple routers on the same, multiaccess broadcast network segment. This significantly reduces the amount of OSPF routing updates sent across the network.
Can a router be ABR and Asbr?
An ABR by definition has links in two or more areas. In OSPF, routers always form the boundaries between areas. A router with links outside the OSPF routing domain is called an autonomous system boundary router (ASBR).
Why did only the ABR need to know that the area was totally stubby rather than all routers in the area?
Q- Why did only the ABR need to know that the area was totally stubby rather than all routers in the area? Ans:The ABR is the gateway to the rest of the area and therefore is the boundary that all inter-area LSAs need to pass through.
What is the difference between ABR and Asbr?
ABR is a router used to establish a connection between backbone area and other OSPF areas. ASBR is a router that is connected to other OSPF areas, as well as other routing protocols such as IGRP, EIGRP, IS-IS, RIP, BGP, Static.
How is NSSA boundary router propagated into OSPF?
An NSSA autonomous system boundary router (ASBR) generates this LSA and an NSSA area border router (ABR) translates it into a type 5 LSA, which gets propagated into the OSPF domain. The network diagram demonstrates this principle. Refer to this network diagram as you use this document: In the network diagram, Area 1 is defined as a stub area.
Can a NSSA ASBR generate a default route?
NSSA ASBR can generate a default only when it has a default route in its routing table. NSSA ABR can generate a default route with or without a default route in its own routing table. This command is used in order to generate an NSSA default route:
Which is the Designated Router for OSPF R1 or R3?
Answer is that R1 will be DR and R3 will be BDR. This can be seen from the “show ip ospf neighbours” on any of the routers. As already mentioned, OSPF DR election is by a non-preemptive election.
How does the Dr work on an OSPF router?
This can be seen from the “show ip ospf neighbours” on any of the routers. As already mentioned, OSPF DR election is by a non-preemptive election. This means that even if we change the priorities so that some other router will have better preference, until the current DR is active, new elections will not start.