Q1. - (Topic 2)
What does a router do if it has no EIGRP feasible successor route to a destination network and the successor route to that destination network is in active status?
A. It routes all traffic that is addressed to the destination network to the interface indicated in the routing table.
B. It sends a copy of its neighbor table to all adjacent routers.
C. It sends a multicast query packet to all adjacent neighbors requesting available routing paths to the destination network.
D. It broadcasts Hello packets to all routers in the network to re-establish neighbor adjacencies.
Answer: C
Explanation:
Introduction to EIGRP Reference:
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080093f07.shtml
Feasible Successors
A destination entry is moved from the topology table to the routing table when there is a feasible successor. All minimum cost paths to the destination form a set. From this set, the neighbors that have an advertised metric less than the current routing table metric are considered feasible successors.
Feasible successors are viewed by a router as neighbors that are downstream with respect to the destination.
These neighbors and the associated metrics are placed in the forwarding table.
When a neighbor changes the metric it has been advertising or a topology change occurs in the network, the set of feasible successors may have to be re-evaluated. However, this is not categorized as a route recomputation.
Route States
A topology table entry for a destination can have one of two states. A route is considered in the Passive state when a router is not performing a route recomputation. The route is in Active state when a router is undergoing a route recomputation. If there are always feasible successors, a route never has to go into Active state and avoids a route recomputation.
When there are no feasible successors, a route goes into Active state and a route recomputation occurs. A route recomputation commences with a router sending a query packet to all neighbors. Neighboring routers can either reply if they have feasible successors for the destination or optionally return a query indicating that they are performing a route recomputation. While in Active state, a router cannot change the next-hop neighbor it is using to forward packets. Once all replies are received for a given query, the destination can transition to Passive state and a new successor can be selected.
When a link to a neighbor that is the only feasible successor goes down, all routes through that neighbor commence a route recomputation and enter the Active state.
Q2. - (Topic 2)
Which statement describes an EIGRP feasible successor route?
A. A primary route, added to the routing table
B. A backup route, added to the routing table
C. A primary route, added to the topology table
D. A backup route, added to the topology table
Answer: D
Explanation:
Two terms that appear often in the EIGRP world are "successor" and "feasible successor". A successor is the route with the best metric to reach a destination. That route is stored in the routing table. A feasible successor is a backup path to reach that same destination that can be used immediately if the successor route fails. These backup routes are stored in the topology table.
Reference: http://study-ccna.com/eigrp-overview
Q3. - (Topic 1)
What is one benefit of PVST+?
A. PVST+ supports Layer 3 load balancing without loops.
B. PVST+ reduces the CPU cycles for all the switches in the network.
C. PVST+ allows the root switch location to be optimized per VLAN.
D. PVST+ automatically selects the root bridge location, to provide optimized bandwidth usage.
Answer: C
Explanation:
Per VLAN Spanning Tree (PVST) Introduction http://www.cisco.com/en/US/tech/tk389/tk621/tk846/tsd_technology_support_sub-protocol_home.html Per VLAN Spanning Tree (PVST) maintains a spanning tree instance for each VLAN configured in the network. This means a switch can be the root bridge of a VLAN while another switch can be the root bridge of other VLANs in a common topology. For example, Switch 1 can be the root bridge for Voice data while Switch 2 can be the root bridge for Video data. If designed correctly, it can optimize the network traffic. http://www.ciscopress.com/articles/article.asp?p=102157&seqNum=4
Topic 2, Routing Technologies
Q4. - (Topic 2)
Refer to the exhibit.
Which three EIGRP routes will be present in the router R4's routing table? (Choose three.)
A. 172.16.1.0/24
B. 10.1.10.0/30
C. 10.0.0.0/8
D. 10.1.11.0/30
E. 172.16.0.0/16
F. 192.168.1.0/24
Answer: C,E,F
Explanation:
EIGRP performs an auto-summarization each time it crosses a border between two different major networks, so when R2 advertises the routes to R4 it will advertise only the summarized routes of 10.0.0.0/8 and 172.16.0.0/16, along with the 192.168.1.0/24 route coming from R3.
Q5. - (Topic 3)
What are three reasons that an organization with multiple branch offices and roaming users might implement a Cisco VPN solution instead of point-to-point WAN links? (Choose three.)
A. reduced cost
B. better throughput
C. broadband incompatibility
D. increased security
E. scalability
F. reduced latency
Answer: A,D,E
Explanation: Cisco VPN solutions provide exceptional security through encryption and authentication technologies that protect data in transit from unauthorized access and attacks. A Cisco VPN helps you: Use highly secure communications, with access rights tailored to individual users Quickly add new sites or users, without significantly expanding your existing infrastructure Improve productivity by extending corporate networks, applications, and collaboration tools Reduce communications costs while increasing flexibility
Q6. - (Topic 3)
Which protocol is an open standard protocol framework that is commonly used in VPNs, to provide secure end-to-end communications?
A. RSA
B. L2TP
C. IPsec
D. PPTP
Answer: C
Explanation:
Internet Protocol Security (IPsec) is a technology protocol suite for securing Internet Protocol (IP) communications by authenticating and/or encrypting each IP packet of a communication session. IPsec also includes protocols for establishing mutual authentication between agents at the beginning of the session and negotiation of cryptographic keys to be used during the session.
Q7. - (Topic 3)
What can be done to Frame Relay to resolve split-horizon issues?(Choose two.)
A. Disable Inverse ARP.
B. Create a full-mesh topology.
C. Develop multipoint subinterfaces.
D. Configure point-to-point subinterfaces.
E. Remove the broadcast keyword from the frame-relay map command.
Answer: B,D
Explanation:
IP split horizon checking is disabled by default for Frame Relay encapsulation to allow routing updates to go in and out of the same interface. An exception is the Enhanced Interior Gateway Routing Protocol (EIGRP) for which split horizon must be explicitly disabled. Certain protocols such as AppleTalk, transparent bridging, and Internetwork Packet Exchange (IPX) cannot be supported on partially meshed networks because they require split horizon to be enabled (a packet received on an interface cannot be transmitted over the same interface, even if the packet is received and transmitted on different virtual circuits). Configuring Frame Relay subinterfaces ensures that a single physical interface is treated as multiple virtual interfaces. This capability allows you to overcome split horizon rules so packets received on one virtual interface can be forwarded to another virtual interface, even if they are configured on the same physical interface.
Q8. - (Topic 2)
Which commands are required to properly configure a router to run OSPF and to add network 192.168.16.0/24 to OSPF area 0? (Choose two.)
A. Router(config)# router ospf 0
B. Router(config)# router ospf 1
C. Router(config)# router ospf area 0
D. Router(config-router)# network 192.168.16.0 0.0.0.255 0
E. Router(config-router)# network 192.168.16.0 0.0.0.255 area 0
F. Router(config-router)# network 192.168.16.0 255.255.255.0 area 0
Answer: B,E
Explanation:
In the router ospf Command, the ranges from 1 to 65535 so o is an invalid number - B is correct but A is not correct. To configure OSPF, we need a wildcard in the “network” statement, not a subnet mask. We also need to assign an area to this process - E is correct.
Q9. - (Topic 2)
A router is running three routing processes: RIP, OSPF, and EIGRP, each configured with default characteristics. Each process learns a route to the same remote network.
If there are no static routes to the destination and none of the routes were redistributed, which route will be placed in the IP routing table?
A. the route learned through EIGRP
B. the route learned through OSPF
C. the route learned through RIP
D. the route with the lowest metric
E. all three routes with the router load balancing
Answer: A
Reference:
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094195.shtml
Administrative distance is the feature that routers use in order to select the best path.
Administrative distance defines the reliability of a routing protocol. Each routing protocol is prioritized in order of most to least reliable (believable) with the help of an administrative distance value. Lowest Administrative distance will be chosen first.
Q10. - (Topic 1)
What are two characteristics of a switch that is configured as a VTP client? (Choose two.)
A. If a switch that is configured to operate in client mode cannot access a VTP server, then the switch reverts to transparent mode.
B. On switches that are configured to operate in client mode, VLANs can be created, deleted, or renamed locally.
C. The local VLAN configuration is updated only when an update that has a higher configuration revision number is received.
D. VTP advertisements are not forwarded to neighboring switches that are configured in VTP transparent mode.
E. VTP client is the default VTP mode.
F. When switches in VTP client mode are rebooted, they send a VTP advertisement request to the VTP servers.
Answer: C,F
Explanation:
VLAN Trunking Protocol (VTP) http://archive.networknewz.com/2004/0317.html
VTP Modes Server Mode Once VTP is configured on a Cisco switch, the default mode used is Server Mode. In any given VTP management domain, at least one switch must be in Server Mode. When in Server Mode, a switch can be used to add, delete, and modify VLANs, and this information will be passed to all other switches in the VTP management domain. Client Mode When a switch is configured to use VTP Client Mode, it is simply the recipient of any VLANs added, deleted, or modified by a switch in Server Mode within the same management domain. A switch in VTP client mode cannot make any changes to VLAN information. Transparent Mode A switch in VTP Transparent Mode will pass VTP updates received by switches in Server Mode to other switches in the VTP management domain, but will not actually process the contents of these messages. When individual VLANs are added, deleted, or modified on a switch running in transparent mode, the changes are local to that particular switch only, and are not passed to other switches in the VTP management domain.