Cisco 640-802 Online Practice Questions and Exam Preparation

Cisco 640-802 Online Questions & Answers

• Question 341:

  What are two enhancements that OSPFv3 supports over OSPFv2? (Choose two.)

  A. It requires the use of ARP.
  B. It can support multiple IPv6 subnets on a single link.
  C. It supports up to 2 instances of OSPFv3 over a common link.
  D. It routes over links rather than over networks.
  B. It can support multiple IPv6 subnets on a single link.
  D. It routes over links rather than over networks.

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  Here is a list of the differences between OSPFv2 and OSPFv3:

  They use different address families (OSPFv2 is for IPv4-only, OSPFv3 can be used for IPv6-only or both protocols

  

  OSPFv3 introduces new LSA types

  

  OSPFv3 has different packet format

  

  OSPFv3 uses different flooding scope bits (U/S2/S1)

  

  OSPFv3 adjacencies are formed over link-local IPv6 communications

  

  OSPFv3 runs per-link rather than per-subnet

  

  OSPFv3 supports multiple instances on a single link, Interfaces can have multiple IPv6 addresses

  

  OSPFv3 uses multicast addresses FF02::5 (all OSPF routers), FF02::6 (all OSPF DRs)

  

  OSPFv3 Neighbor Authentication done with IPsec (AH)

  

  OSPFv2 Router ID (RID) must be manually configured, still a 32-bit number

  

  Reference: http://www.networkworld.com/article/2225270/cisco-subnet/ospfv3-for-ipv4-and-ipv6.html

• Question 342:

  Which two statements about IPv6 and routing protocols are true? (Choose two.)

  A. Link-local addresses are used to form routing adjacencies.
  B. OSPFv3 was developed to support IPv6 routing.
  C. EIGRP, OSPF, and BGP are the only routing protocols that support IPv6.
  D. Loopback addresses are used to form routing adjacencies.
  E. EIGRPv3 was developed to support IPv6 routing.
  A. Link-local addresses are used to form routing adjacencies.
  B. OSPFv3 was developed to support IPv6 routing.

• Question 343:

  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. a directly connected interface with an address of 192.168.10.254/24
  B. a static route to network 192.168.10.0/24
  C. a RIP update for network 192.168.10.0/24
  D. an OSPF update for network 192.168.0.0/16
  E. a default route with a next hop address of 192.168.10.1
  F. a static route to network 192.168.10.0/24 with a local serial interface configured as the next hop
  A. a directly connected interface with an address of 192.168.10.254/24

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  When there is more than one way to reach a destination, it will choose the best one based on a couple of things. First, it will choose the route that has the longest match; meaning the most specific route. So, in this case the /24 routes will be chosen over the /16 routes. Next, from all the /24 routes it will choose the one with the lowest administrative distance. Directly connected routes have an AD of 1 so this will be the route chosen.

• Question 344:

  In GLBP, which router will respond to client ARP requests?

  A. The active virtual gateway will reply with one of four possible virtual MAC addresses.
  B. All GLBP member routers will reply in round-robin fashion.
  C. The active virtual gateway will reply with its own hardware MAC address.
  D. The GLBP member routers will reply with one of four possible burned in hardware addresses.
  A. The active virtual gateway will reply with one of four possible virtual MAC addresses.

  ---

  One disadvantage of HSRP and VRRP is that only one router is in use, other routers must wait for the primary to fail because they can be used. However, Gateway Load Balancing Protocol (GLBP) can use of up to four routers simultaneously. In GLBP, there is still only one virtual IP address but each router has a different virtual MAC address. First a GLBP group must elect an Active Virtual Gateway (AVG). The AVG is responsible for replying ARP requests from hosts/clients. It replies with different virtual MAC addresses that correspond to different routers (known as Active Virtual Forwarders ?AVFs) so that clients can send traffic to different routers in that GLBP group (load sharing).

• Question 345:

  What authentication type is used by SNMPv2?

  A. HMAC-MD5
  B. HMAC-SHA
  C. CBC-DES
  D. community strings
  D. community strings

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  SNMP Versions

  Cisco IOS software supports the following versions of SNMP:

  SNMPv1 -- The Simple Network Management Protocol: A Full Internet Standard, defined in RFC 1157. (RFC 1157 replaces the earlier versions that were published as RFC 1067 and RFC 1098.) Security is based on community strings.

  

  SNMPv2c -- The community-string based Administrative Framework for SNMPv2. SNMPv2c (the "c" stands for "community") is an Experimental Internet Protocol defined in RFC 1901, RFC 1905, and RFC 1906. SNMPv2c is an update of

  

  the protocol operations and data types of SNMPv2p (SNMPv2 Classic), and uses the community-based security model of SNMPv1.

  SNMPv3 -- Version 3 of SNMP. SNMPv3 is an interoperable standards-based protocol defined in RFCs 2273 to 2275. SNMPv3 provides secure access to devices by a combination of authenticating and encrypting packets over the

  

  network.

  

  Reference: http://www.cisco.com/c/en/us/td/docs/ios/12_2/configfun/configuration/guide/ffun_c/fcf014.html

• Question 346:

  Which two spanning-tree port states does RSTP combine to allow faster convergence? (Choose two.)

  A. blocking
  B. listening
  C. learning
  D. forwarding
  E. discarding
  A. blocking
  B. listening

• Question 347:

  Scenario Refer to the topology. Your company has decided to connect the main office with three other remote branch offices using point-to-point serial links. You are required to troubleshoot and resolve OSPF neighbor adjacency issues between the main office and the routers located in the remote branch offices.

  

  

  

  An OSPF neighbor adjacency is not formed between R3 in the main office and R5 in the Branch2 office. What is causing the problem?

  A. There is an area ID mismatch.
  B. There is a PPP authentication issue; a password mismatch.
  C. There is an OSPF hello and dead interval mismatch.
  D. There is a missing network command in the OSPF process on R5.
  C. There is an OSPF hello and dead interval mismatch.

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  The "show ip ospf interface command on R3 and R5 shows that the hello and dead intervals do not match. They are 50 and 200 on R3 and 10 and 40 on R5.

  

• Question 348:

  At which layer of the OSI model does PPP perform?

  A. Layer 2
  B. Layer 3
  C. Layer 4
  D. Layer 5
  A. Layer 2

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  The Point-to-Point Protocol (PPP) provides a standard method for transporting multi-protocol datagrams over point-to-point links. PPP was originally emerged as an encapsulation protocol for transporting IP traffic between two peers. It is a data link layer protocol (layer 2 in the OSI model)

• Question 349:

  A network administrator needs to allow only one Telnet connection to a router. For anyone viewing the configuration and issuing the show run command, the password for Telnet access should be encrypted. Which set of commands will accomplish this task?

  A. service password-encryption access-list 1 permit 192.168.1.0 0.0.0.255 line vty 0 4 login password cisco access-class 1
  B. enable password secret line vty 0 login password cisco
  C. service password-encryption line vty 1 login password cisco
  D. service password-encryption line vty 0 4 login password cisco
  C. service password-encryption line vty 1 login password cisco

  ---

  Only one VTY connection is allowed which is exactly what's requested.

  Incorrect answer: command.

  line vty0 4

  would enable all 5 vty connections.

• Question 350:

  What are two benefits of using NAT? (Choose two.)

  A. NAT facilitates end-to-end communication when IPsec is enabled.
  B. NAT eliminates the need to re-address all hosts that require external access.
  C. NAT conserves addresses through host MAC-level multiplexing.
  D. Dynamic NAT facilitates connections from the outside of the network.
  E. NAT accelerates the routing process because no modifications are made on the packets.
  F. NAT protects network security because private networks are not advertised.
  B. NAT eliminates the need to re-address all hosts that require external access.
  F. NAT protects network security because private networks are not advertised.

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  By not revealing the internal IP addresses, NAT adds some security to the inside network -> F is correct.

  NAT has to modify the source IP addresses in the packets -> E is not correct.

  Connection from the outside of the network through a "NAT" network is more difficult than a more network because IP addresses of inside hosts are hidden -> C is not correct.

  In order for IPsec to work with NAT we need to allow additional protocols, including Internet Key Exchange (IKE), Encapsulating Security Payload (ESP) and Authentication Header (AH) -> more complex -> A is not correct.

  By allocating specific public IP addresses to inside hosts, NAT eliminates the need to re-address the inside hosts -> B is correct.

  NAT does conserve addresses but not through host MAC-level multiplexing. It conserves addresses by allowing many private IP addresses to use the same public IP address to go to the Internet -> C is not correct.