No DR is assigned on any type of point-to-point link. No DR/BDR is assigned on the NBMA point-to-multipoint due to the hub/spoke topology. DR and BDR are elected on broadcast and non-broadcast multi-access networks. Frame Relay is a non-Broadcast Multi-Access (NBMA) network by default.
2. Which of the following protocols support VLSM, summarization, and discontiguous networking?
RIPv1 and IGRP are true distance-vector routing protocols and can't do much, really-except build and maintain routing tables and use a lot of bandwidth! RIPv2, EIGRP, and OSPF build and maintain routing tables, but they also provide classless routing, which allows for VLSM, summarization, and discontiguous networking.
The administrative distance (AD) is a very important parameter in a routing protocol. The lower the AD, the more trusted the route. If you have IGRP and OSPF running, by default IGRP routes would be placed in the routing table because IGRP has a lower AD of 100. OSPF has an AD of 110. RIPv1 and RIPv2 both have an AD of 120, and EIGRP is the lowest, at 90.
4. Which EIGRP information is held in RAM and maintained through the use of Hello and update packets?
EIGRP holds three tables in RAM: neighbor, topology, and routing. The neighbor and topology tables are built and maintained with the use of Hello packets.
5. Your company is running IGRP using an AS of 10. You want to configure EIGRP on the network but want to migrate slowly to EIGRP and don't want to configure redistribution. What command would allow you to migrate over time to EIGRP without configuring redistribution?
If you enable EIGRP on a router with the same autonomous system (AS) number, EIGRP will automatically redistribute IGRP into EIGRP. You will see the IGRP injected routes as external (EX) routes with an EIGRP AD of 170. This is a nice feature that lets you migrate slowly to EIGRP with no extra configuration.
6. Which two of the following commands will place network 10.2.3.0/24 into area 0?
To enable OSPF, you must first start OSPF using a Process ID. The number is irrelevant; just choose a number from 1 to 65,535 and you're good to go. After you start the OSPF process, you must configure any network that you want advertised via OSPF using wildcards and the area command. Statement (4) is wrong because there must be a space after the parameter area and before you list the area number.
7. A network administrator needs to configure a router with a distance-vector protocol that allows classless routing. Which of the following satisfies those requirements?
In this question, we're calling EIGRP just plain old distance vector. EIGRP is an "advanced" distance-vector routing protocol, sometimes called a hybrid routing protocol because it uses the characteristics of both distance-vector and link-state routing protocols.
8. If routers in a single area are configured with the same priority value, what value does a router use for the OSPF Router ID in the absence of a loopback interface?
Options
A. The lowest IP address of any physical interface
B. The highest IP address of any physical interface
C. The lowest IP address of any logical interface
D. The highest IP address of any logical interface
Correct Answer: The highest IP address of any physical interface
Explanation:
At the moment of OSPF process startup, the highest IP address on any active interface will be the Router ID (RID) of the router. If you have a loopback interface configured (logical interface), then that will override the interface IP address and become the RID of the router automatically.
9. Which of the following are true regarding OSPF areas?
You must have separate loopback interfaces configured in each area.
The numbers you can assign an area go up to 65,535.
The backbone area is also called area 0.
If your design is hierarchical, then you don't need multiple areas.
Loopback interfaces are created on a router, and the highest IP address on a loopback (logical) interface becomes the RID of the router but has nothing to do with areas and is optional, so (1) is wrong. The numbers you can create an area with are from 0 to 4,294,967,295 option (2) is wrong. The backbone area is called area 0, so option (3) is correct. All areas must connect to area 0, so option (5) is correct. If you have only one area, it must be called area 0. This leaves option (4), which must be correct; it doesn't make much sense, but it is the best answer.
10. Which of the following describe the process identifier that is used to run OSPF on a router?
It is locally significant.
It is globally significant.
It is needed to identify a unique instance of an OSPF database.
It is an optional parameter required only if multiple OSPF processes are running on the router.
The Process ID for OSPF on a router is only locally significant and you can use the same number on each router, or each router can have a different number-it just doesn't matter. The numbers you can use are from 1 to 65,535. Don't get this confused with area numbers, which can be from 0 to 4.2 billion.