Why do large OSPF networks use a hierarchical design? (Choose three.) A . to decrease latency by increasing bandwidth B . to reduce routing overhead C . to speed up convergence D . to confine network instability to single areas of the network E . to reduce the complexity of router configuration F . to lower costs by replacing routers with distribution layer switches
OSPF implements a two-tier hierarchical routing model that uses a core or backbone tier known as area zero (0). Attached to that backbone via area border routers (ABRs) are a number of secondary tier areas. The hierarchical approach is used to achieve the following:
– Rapid convergence because of link and/or switch failures
– Deterministic traffic recovery
– Scalable and manageable routing hierarchy, reduced routing overhead.
Which address type does a switch use to make selective forwarding decisions? A . source IP address B . destination IP address C . source and destination IP address D . source MAC address E . destination MAC address
Switches analyze the destination MAC to make its forwarding decision since it is a layer 2 device. Routers use the destination IP address to make forwarding decisions.
The output is from a router in a large enterprise. From the output, determine the role of the router. A . A Core router. B . The HQ Internet gateway router. C . The WAN router at the central site. D . Remote stub router at a remote site.
If a host experiences intermittent issues that relate to congestion within a network while remaining connected, what could cause congestion on this LAN? A . half-duplex operation B . broadcast storms C . network segmentation D . multicasting
A broadcast storm can consume sufficient network resources so as to render the network unable to transport normal traffic.
Which of the following describe the process identifier that is used to run OSPF on a router? (Choose two) A . It is locally significant. B . It is globally significant. C . It is needed to identify a unique instance of an OSPF database. D . It is an optional parameter required only if multiple OSPF processes are running on the router. E . All routers in the same OSPF area must have the same process ID if they are to exchange routing information.
They are locally significant only, and have no bearing on the structure of any OSPF packet or LSA update. So you can have a separate process-id on every single router in your network if you so desire!
Which two of these functions do routers perform on packets? (Choose two.) A . examine the Layer 2 headers of inbound packets and use that information to determine the next hops for the packets B . update the Layer 2 headers of outbound packets with the MAC addresses of the next hops C . examine the Layer 3 headers of inbound packets and use that information to determine the next hops for the packets D . examine the Layer 3 headers of inbound packets and use that information to determine the complete paths along which the packets will be routed to their ultimate destinations E . update the Layer 3 headers of outbound packets so that the packets are properly directed to valid next hops F . update the Layer 3 headers of outbound packets so that the packets are properly directed to their ultimate destinations
This is the basic function of the router to receive incoming packets and then forward them to their required destination. This is done by reading layer 3 headers of inbound packets and update the info to layer 2 for further hopping.