Q1. - (Topic 2)
Which two are advantages of static routing when compared to dynamic routing? (Choose two.)
A. Configuration complexity decreases as network size increases.
B. Security increases because only the network administrator may change the routing table.
C. Route summarization is computed automatically by the router.
D. Routing tables adapt automatically to topology changes.
E. An efficient algorithm is used to build routing tables, using automatic updates.
F. Routing updates are automatically sent to neighbors.
G. Routing traffic load is reduced when used in stub network links.
Answer: B,G
Explanation:
When reading (or being lectured about) all the glorious details of dynamic routing protocols, it's hard not to come away with the impression that dynamic routing is always better than static routing. It's important to keep in mind that the primary duty of a dynamic routing protocol is to automatically detect and adapt to topological changes in the internetwork. The price of this "automation" is paid in bandwidth, security, and maybe queue space, in memory, and in processing time. A frequent objection to static routing is that it is hard to administer. This criticism may be true of medium to large topologies with many alternative routes, but it is certainly not true of small internetworks with few or no alternative routes. References: http://www.ciscopress.com/articles/article.asp?p=24090&seqNum=6 http://www.ciscopress.com/articles/article.asp?p=24090
Q2. - (Topic 2)
Refer to the exhibit.
Given the output from the “show ip eigrp topology” command, which router is the feasible successor?
A)
B)
C)
D)
A. Exhibit A
B. Exhibit B
C. Exhibit C
D. Exhibit D
Answer: B
Explanation:
To be the feasible successor, the Advertised Distance (AD) of that route must be less than the Feasible Distance (FD) of the successor. From the output of the “show ip eigrp topology
10.0.0.5 255.255.255.255 we learn that the FD of the successor is 41152000. Now we will mention about the answers, in the “Composite metric is (…/…)” statement the first parameter is the FD while the second parameter is the AD of that route. So we need to find out which route has the second parameter (AD) less than 41152000 -> only answer B satisfies this requirement with an AD of 128256.
Reference: http://networklessons.com/eigrp/eigrp-neighbor-and-topology-table-explained/
Q3. - (Topic 2)
Which type of EIGRP route entry describes a feasible successor?
A. a backup route, stored in the routing table
B. a primary route, stored in the routing table
C. a backup route, stored in the topology table
D. a primary route, stored in the topology table
Answer: C
Explanation:
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. Feasible successor is a route whose Advertised Distance (AD) is less than the Feasible Distance (FD) of the current best path. A feasible successor is a backup route, which is not stored in the routing table but, stored in the topology table.
Q4. - (Topic 1)
Refer to the exhibit.
The output that is shown is generated at a switch. Which three statements are true? (Choose three.)
A. All ports will be in a state of discarding, learning, or forwarding.
B. Thirty VLANs have been configured on this switch.
C. The bridge priority is lower than the default value for spanning tree.
D. All interfaces that are shown are on shared media.
E. All designated ports are in a forwarding state.
F. This switch must be the root bridge for all VLANs on this switch.
Answer: A,C,E
Explanation:
From the output, we see that all ports are in Designated role (forwarding state) -> A and E
are correct.
The command “show spanning-tree vlan 30 only shows us information about VLAN 30. We
don’t know how many VLAN exists in this switch -> B is not correct.
The bridge priority of this switch is 24606 which is lower than the default value bridge
priority 32768 -> C is correct.
All three interfaces on this switch have the connection type “p2p”, which means Point-to-point environment – not a shared media -> D is not correct.
The only thing we can specify is this switch is the root bridge for VLAN 3o but we can not
guarantee it is also the root bridge for other VLANs -> F is not correct.
Q5. - (Topic 2)
A router receives information about network 192.168.10.0/24 from multiple sources. What will the router consider the most reliable information about the path to that network?
A. an OSPF update for network 192.168.0.0/16
B. a static route to network 192.168.10.0/24
C. a static route to network 192.168.10.0/24 with a local serial interface configured as the next hop
D. a RIP update for network 192.168.10.0/24
E. a directly connected interface with an address of 192.168.10.254/24
F. a default route with a next hop address of 192.168.10.1
Answer: E
Explanation:
What Is Administrative Distance? http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094195.shtml
Select the Best Path Administrative distance is the first criterion that a router uses to determine which routing protocol to use if two protocols provide route information for the same destination. Administrative distance is a measure of the trustworthiness of the source of the routing information. Administrative distance has only local significance, and is not advertised in routing updates. Note: The smaller the administrative distance value, the more reliable the protocol. For example, if a router receives a route to a certain network from both Open Shortest Path First (OSPF) (default administrative distance - 110) and Interior Gateway Routing Protocol (IGRP) (default administrative distance - 100), the router chooses IGRP because IGRP is more reliable. This means the router adds the IGRP version of the route to the routing table.
Q6. - (Topic 2)
What is the default administrative distance of OSPF?
A. 90
B. 100
C. 110
D. 120
Answer: C
Explanation:
Default Distance Value Table This table lists the administrative distance default values of the protocols that Cisco supports:
Q7. - (Topic 2)
What are two drawbacks of implementing a link-state routing protocol? (Choose two.)
A. the sequencing and acknowledgment of link-state packets B. the requirement for a hierarchical IP addressing scheme for optimal functionality
C. the high volume of link-state advertisements in a converged network
D. the high demand on router resources to run the link-state routing algorithm
E. the large size of the topology table listing all advertised routes in the converged network
Answer: B,D
Explanation:
Link State routing protocols, such as OSPF and IS-IS, converge more quickly than their distance vector routing protocols such as RIPv1, RIPv2, EIGRP and so on, through the use of flooding and triggered updates. In link state protocols, changes are flooded immediately and computed in parallel. Triggered updates improve convergence time by requiring routers to send an update message immediately upon learning of a route change. These updates are triggered by some event, such as a new link becoming available oor an existing link failing. The main drawbacks to link state routing protocols are the amount of CPU overhead involved in calculating route changes and memory resources that are required to store neighbor tables, route tables and a complete topology table. http://www.ciscopress.com/articles/article.asp?p=24090&seqNum=4
Q8. - (Topic 3)
The command frame-relay map ip 10.121.16.8 102 broadcast was entered on the router. Which of the following statements is true concerning this command?
A. This command should be executed from the global configuration mode.
B. The IP address 10.121.16.8 is the local router port used to forward data.
C. 102 is the remote DLCI that will receive the information.
D. This command is required for all Frame Relay configurations.
E. The broadcast option allows packets, such as RIP updates, to be forwarded across the PVC.
Answer: E
Explanation:
The command frame-relay map ip 10.121.16.8 102 broadcast means to map the remote IP
10.121.16.8 to the local DLCI 102. When the “broadcast” keyword is included, it turns Frame Relay network as a broadcast network, which can forward broadcasts.
Q9. - (Topic 2)
Refer to the exhibit.
The network associate is configuring OSPF on the Core router. All the connections to the branches should be participating in OSPF. The link to the ISP should NOT participate in OSPF and should only be advertised as the default route. What set of commands will properly configure the Core router?
A. Core(config-router)# default-information originate Core(config-router)# network 10.0.0.0 0.255.255.255 area 0 Core(config-router)# exit Core(config)# ip route 0.0.0.0 0.0.0.0 10.10.2.14
B. Core(config-router)# default-information originate Core(config-router)# network 10.10.2.13 0.0.0.242 area 0 Core(config-router)# exit Core(config)# ip route 0.0.0.0 0.0.0.0 10.10.2.14
C. Core(config-router)# default-information originate Core(config-router)# network 10.10.2.16 0.0.0.15 area 0 Core(config-router)# exit Core(config)# ip route 0.0.0.0 0.0.0.0 10.10.2.14
D. Core(config-router)# default-information originate Core(config-router)# network 10.10.2.32 0.0.0.31 area 0 Core(config-router)# exit Core(config)# ip route 0.0.0.0 0.0.0.0 10.10.2.14
Answer: C
Explanation:
There are two ways to inject a default route into a normal area.1. If the ASBR already has the default route in its routing table, you can advertise theexisting 0.0.0.0/0 into the OSPF domain with the default-information originate router configuration command.2. If the ASBR doesn’t have a default route, you can add the keyword always to the default-information originate command (default-information originate always).This command will advertise a default route into the OSPF domain, regardless of whether it has a route to 0.0.0.0. Another benefit of adding always keyword is that it can add stability to the internetwork. For example, if the ASBR is learning a default route from another routing domain such as RIP and this route is flapping, then without the always keyword, each time the route flaps, the ASBR will send a new Type 5 LSA into the OSPF domain causing some instability inside the OSPF domain. With the always keyword, the ASBR will advertise the default inside the OSPF domain always, In the example shown here, only choice C is correct as the wildcard mask correctly specifies the 10.10.2.16 0.0.0.15 networks, which include all IP addresses in the 10.10.2.16-10.10.2.31 range. In this question we were told that the ISP link should NOT be configured for OSPF, making choice A incorrect. http://www.cisco.com/en/US/tech/tk365/technologies_configuration_example09186a00801 ec9f0.shtml
Q10. - (Topic 3)
Which command is used to enable CHAP authentication, with PAP as the fallback method, on a serial interface?
A. Router(config-if)# ppp authentication chap fallback ppp
B. Router(config-if)# ppp authentication chap pap
C. Router(config-if)# authentication ppp chap fallback ppp
D. Router(config-if)# authentication ppp chap pap
Answer: B
Explanation:
The command “ppp authentication chap pap” command indicates the CHAP authentication is used first. If it fails or is rejected by other side then uses PAP instead. If you want to use PAP first (then CHAP) you can use the “ppp authentication pap chap” command
Reference: http://www.cisco.com/en/US/docs/ios/12_2/security/configuration/guide/scfathen.html