T INFO 250 Ch 6 Exam
Which two pieces of information are in the RAM of a Cisco router during normal operation? (Choose two.)
Cisco IOS* IP routing table* Explain: The Cisco IOS file is stored in flash memory and copied into RAM during the boot up. The IP routing table is also stored in RAM. The basic diagnostic software is stored in ROM and the startup configuration file is stored in NVRAM.
Match the command with the device mode at which the command is entered. (Not all options are used.)
Explain: The enable command is entered in R1> mode. The login command is entered in R1(config-line)# mode. The copy running-config startup-config command is entered in R1# mode. The ip address 192.168.4.4 255.255.255.0 command is entered in R1(config-if)# mode. The service password-encryption command is entered in global configuration mode.
Which statement describes a hardware feature of a Cisco 1941 router that has the default hardware configuration?
It has two types of ports that can be used to access the console.* Explain: The connections in a Cisco 1941 router include two types of ports that are used for initial configuration and command-line interface management access. The two ports are the regular RJ-45 port and a new USB Type-B (mini-B USB) connector. In addition, the router has an AUX port for remote management access, and two Gigabit Ethernet interfaces for LAN access. Compact Flash can be used increase device storage, but it does not perform the functions of the CPU, which is required for operation of the device.
What are two types of router interfaces? (Choose two.)
LAN* WAN* Explain: Router interfaces can be grouped into two categories: · LAN interfaces - Used for connecting cables that terminate with LAN devices, such as computers and switches. This interface can also be used to connect routers to each other. · WAN interfaces - Used for connecting routers to external networks, usually over a larger geographical distance
Following default settings, what is the next step in the router boot sequence after the IOS loads from flash?
Locate and load the startup-config file from NVRAM.* Explain: There are three major steps to the router boot sequence: Perform Power-On-Self-Test (POST) Load the IOS from Flash or TFTP server Load the startup configuration file from NVRAM
Refer to the exhibit. Which route from the PC1 routing table will be used to reach PC2?
Network Destination: 192.168.10.0 Netmask: 255.255.255.0 Gateway: On-link Interface: 192.168.10.10 Metric: 281 Explain: PC1 and PC2 are both on network 192.168.10.0 with mask 255.255.255.0, so there is no need to access the default gateway (entry 0.0.0.0 0.0.0.0). Entry 127.0.0.1 255.255.255.255 is the loopback interface and entry 192.168.10.10 255.255.255.255 identifies the PC1 address interface.
What IPv4 header field identifies the upper layer protocol carried in the packet?
Protocol* Explain: It is the Protocol field in the IP header that identifies the upper-layer protocol the packet is carrying. The Version field identifies the IP version. The Differential Services field is used for setting packet priority. The Identification field is used to reorder fragmented packets.
Refer to the exhibit. R1 receives a packet destined for the IP address 192.168.2.10. Out which interface will R1 forward the packet?
Serial0/0/1* Explain: If a route in the routing table points to a next hop address, the router will perform a second lookup to determine out which interface the next hop is located.
Which characteristic describes an IPv6 enhancement over IPv4?
The IPv6 header is simpler than the IPv4 header is, which improves packet handling.* Explain: IPv6 addresses are based on 128-bit hierarchical addressing, and the IPv6 header has been simplified with fewer fields, improving packet handling. IPv6 natively supports authentication and privacy capabilities as opposed to IPv4 that needs additional features to support those. The IPv6 address space is many times bigger than IPv4 address space.
A router boots and enters setup mode. What is the reason for this?
The configuration file is missing from NVRAM.*
Which field in the IPv4 header is used to prevent a packet from traversing a network endlessly?
Time-to-Live* Explain: The value of the Time-to-Live (TTL) field in the IPv4 header is used to limit the lifetime of a packet. The sending host sets the initial TTL value; which is decreased by one each time the packet is processed by a router. If the TTL field decrements to zero, the router discards the packet and sends an Internet Control Message Protocol (ICMP) Time Exceeded message to the source IP address. The Differentiated Services (DS) field is used to determine the priority of each packet. Sequence Number and Acknowledgment Number are two fields in the TCP header.
When a connectionless protocol is in use at a lower layer of the OSI model, how is missing data detected and retransmitted if necessary?
Upper-layer connection-oriented protocols keep track of the data received and can request retransmission from the upper-level protocols on the sending host.* Explain: When connectionless protocols are in use at a lower layer of the OSI model, upper-level protocols may need to work together on the sending and receiving hosts to account for and retransmit lost data. In some cases, this is not necessary, because for some applications a certain amount of data loss is tolerable.
What type of route is indicated by the code C in an IPv4 routing table on a Cisco router?
directly connected route* Explain: Some of the IPv4 routing table codes include the following: C - directly connected S - static D - EIGRP * - candidate default
What are two characteristics of IP? (Choose two.)
does not require a dedicated end-to-end connection * operates independently of the network media* Explain: The Internet Protocol (IP) is a connectionless, best effort protocol. This means that IP requires no end-to-end connection nor does it guarantee delivery of packets. IP is also media independent, which means it operates independently of the network media carrying the packets.
What is one advantage that the IPv6 simplified header offers over IPv4?
efficient packet handling* Explain: The IPv6 simplified header offers several advantages over IPv4: · Better routing efficiency and efficient packet handling for performance and forwarding-rate scalability · No requirement for processing checksums · Simplified and more efficient extension header mechanisms (as opposed to the IPv4 Options field) · A Flow Label field for per-flow processing with no need to open the transport inner packet to identify the various traffic flows
Which three commands are used to set up secure access to a router through a connection to the console interface? (Choose three.)
line console 0* login * password cisco * Explain: The three commands needed to password protect the console port are as follows: line console 0 password cisco login Theinterface fastethernet 0/0 command is commonly used to access the configuration mode used to apply specific parameters such as the IP address to the Fa0/0 port. The line vty 0 4 command is used to access the configuration mode for Telnet. The0and 4 parameters specify ports 0 through 4, or a maximum of five simultaneous Telnet connections. The enable secret command is used to apply a password used on the router to access the privileged mode.
What routing table entry has a next hop address associated with a destination network?
remote routes* Explain: Routing table entries for remote routes will have a next hop IP address. The next hop IP address is the address of the router interface of the next device to be used to reach the destination network. Directly-connected and local routes have no next hop, because they do not require going through another router to be reached.
Which characteristic of the network layer in the OSI model allows carrying packets for multiple types of communications among many hosts?
the ability to operate without regard to the data that is carried in each packet* Explain: The function of the network layer protocols specifies the packet structure and processing used to carry the data from one host to another host. The actual communication data is encapsulated in the network layer PDU. The feature of its operation without regard to the data carried in each packet allows the network layer to carry packets for multiple types of communications.
What is the purpose of the startup configuration file on a Cisco router?
to contain the commands that are used to initially configure a router on startup* Explain: The startup configuration file is stored in NVRAM and contains the commands needed to initially configure a router. It also creates the running configuration file that is stored in in RAM.