Term
A router is any piece of hardware or software that forwards packets based on their destination IP address. Therefore, they work at the ___ layer of the OSI model. (pg. 232)
A. Transport (Layer 4)
B. Data Link (Layer 2)
C. Network (Layer 3)
D. Physical (Layer 1) |
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Definition
| C. Routers work at the Network layer. |
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Term
A list of various networks and the next hop to reach them. (pg. 235)
A. Network tree
B. Address Resolution Protocol (ARP)
C. Routing table
D. Routing loop |
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Definition
| C. The router inspects each packet's destination IP address and then sends the IP packet out the correct port. It uses a routing table that tells it exactly where to send the packets. |
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Term
| True or False: An asterisk (*) in a routing table means to accept anything. (pg. 237) |
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Definition
False. The character used for "anything" in a routing table is a zero (0).
For instance, a destination network ID of 10.12.14.0 means that any value between 1 and 254 is acceptable for the last value in that address. |
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Term
| True or false: When a properly configured router receives a packet without a route, it can query the sending device for more information and update its routing table. (pg. 237) |
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Definition
| False: a router must have a route for any packet it might encounter. |
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Term
A relative value in a routing table that defines the desirability of a route to get a packet to its destination. (pg. 239)
A. Tracer
B. Hop
C. Metric
D. Score |
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Definition
| C. Routers often know more than one route to get a packet to its destination. If the main route goes down, the router can use an alternate to deliver a packet. |
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Term
The networking feature that hides the IP addresses of computers on a LAN but still enables those computers to communicate with the broader Internet. (pg. 244)
A. Network address translation (NAT)
B. Port address translation (PAT)
C. Subnetting
D. Port masking |
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Definition
| A. NAT replaces the source IP address of a computer with the source IP address from the outside router interface on outgoing packets. |
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Term
The form of NAT that uses port numbers to map traffic from specific machines in the network. (pg. 245)
A. Port address translation (PAT)
B. Route tabling
C. Dynamic NAT (DNAT)
D. Port forwarding |
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Definition
| A. PAT allows all computers on a private network to connect to the Internet through a single router by recording IP addresses and port numbers in the NAT device's translation table. The private IP address is swapped for the public IP address on each packet. |
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Term
The form of NAT that allows many computers to share a pool of routable IP addresses that number fewer than the computers. (pg. 247)
A. Dynamic NAT (DNAT)
B. Port address translation (PAT)
C. Shared IP address translation (SIPAT)
D. Address pooling |
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Definition
| A. When a computer requests info beyond the network, the NAT doles out a routable IP address from its pool for that communication. LAN traffic uses the internal, private IP addresses. |
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Term
Form of NAT that allows you to map a single routable IP address to a single machine. (pg. 247)
A. Dynamic routing
B. Static NAT (SNAT)
C. Direct NAT (DNAT)
D. Peer-to-Peer connection (P2P) |
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Definition
| B. SNAT enables you to access that machine from outside the network and vice versa. |
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Term
Feature that allows you to designate a specific local address for various network services. (pg. 247)
A. Local address role assignment
B. Static NAT
C. IP Mapping
D. Port forwarding |
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Definition
D. Computers outside the network can request a service using the public IP address of the router and the port number of the desired service.
The port-forwarding router examines the packet, looks at the list of services mapped to local addresses, and sends the packet to the proper recipient. |
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Term
The process that routers use to update routes to accommodate changes in conditions. (pg. 250)
A. Dynamic routing
B. Port forwarding
C. Network address translation (NAT)
D. Live service |
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Definition
| A. Dynamic routing protocols enable routers to work around connection problems, such as when a line goes down because of an electrical blackout. |
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Term
A fundamental metric value for the number of routers a packet will pass through on the way to its destination network. (pg. 252)
A. Time-to-live (TTL)
B. Cost
C. Hop count
D. Distance Vector |
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Definition
| C. The hop occurs when the packet is handed off to each subsequent router. |
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Term
Some routing protocols use ___ as a metric for the desirability of that particular route. (pg. 252)
A. Bandwidth
B. Path Vector
C. Delay
D. Cost |
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Definition
| D. A network administrator can manually add cost to routes to change the route selection. |
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Term
Routing protocols that calculate the metric number to get to a particular network ID and compare that metric to the metrics of all the other routes to get to that same network ID. (pg. 253)
A. Distance vector
B. Address Resolution Protocol (ARP)
C. Dynamic routing
D. Path Vector |
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Definition
| A. Routers using a distance vector routing protocol transfer their entire routing table to other routers in the WAN. |
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Term
A special, globally unique identifier assigned to one or more networks that share a unified "policy" regarding how they exchange traffic with similar networks. (pg. 258)
A. Global MAC address (GMAC)
B. Network ID (NID)
C. Autonomous System Number (ASN)
D. Business Identification Number (BIN) |
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Definition
| C. Current ASNs are 32-bit, displayed as two 16-bit numbers separated by a dot. |
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Term
When routers in one Autonomous System (AS) need to communicate with routers in another AS, they use a(n) ___ Protocol. The network or networks within an AS communicate with ___ Protocols. (pg. 258)
A. Transfer Control, Address Resolution
B. Hypertext Transfer Secure, Hypertext Transfer
C. Exterior Gateway, Interior Gateway
D. Out-Of-Domain, In-The-Domain |
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Definition
| C. Exterior Gateway, Interior Gateway |
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Term
Although many protocols can be used within each Autonomous System (AS), the Internet uses a single protocol for AS-to-AS communication. What is it? (pg. 259)
A. Routing Information Protocol version 2 (RIPv2)
B. Exterior Gateway Protocol (EGP)
C. Border Gateway Protocol (BGP)
D. Internet Protocol (IP) |
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Definition
C. BGP is the glue of the Internet, connecting all of the ASes. Other dynamic routing protocols are, by definition, Interior Gateway Procols.
The exam may refer to BGP as a hybrid routing protocol. |
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Term
BGP implements and supports ___, a way to simplify routing tables into manageable levels. (pg. 259)
A. Dynamic routing
B. Edge routing
C. Vector paths
D. Route aggregation |
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Definition
| D. Rather than try to keep track of every router on the Internet, the backbone routers track the shortest common network ID(s) of all the routes managed by each Autonomous System. |
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Term
Dynamic routing protocol that announces and forwards individual route changes as they appear instead of at regular intervals. (pg. 260)
A. Routing Information Protocol (RIP)
B. Link state
C. Enhanced Interior Gateway Routing Protocol (EIGRP)
D. Border Gateway Protocol (BGP) |
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Definition
| B. Link state protocols are faster and take up less WAN bandwidth than RIP thanks to their efficiency. |
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Term
The most commonly used Interior Gateway Protocol in the world, it works by having routers initially send out Hello packets to look for other routers. (pg. 260)
A. Enhanced Interior Gateway Routing Protocol (EIGRP)
B. Open Shortest Path First (OSPF)
C. Intermediate System to Intermediate System (IS-IS)
D. Border Gateway Protocol (BGP) |
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Definition
B. After two adjacent routers form a neighborship through the Hello packets, they exchange information about routers and networks through link state advertisement (LSA) packets.
Once all the routers communicate, they individually decide their own optimal routes, and convergence happens almost immediately. |
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Term
True or False:
The Enhanced Interior Gateway Routing Protocol (EIGRP) routing protocol corrects link failures and creates convergence almost immediately, making it the routing protocol of choice in most large enterprise networks. (pg. 261) |
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Definition
| False: EIGRP is Cisco's proprietary routing protocol. OSPF is the most popular one for large enterprise networks, due to its scalability and support. |
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Term
What is the one major advantage that the Intermediate System to Intermediate System (IS-IS) routing protocol has over Open Shortest Path First (OSPF)? (pg. 260)
A. It was made to work with IPv6 from the start.
B. It uses areas (administrative groupings of connected routers)
C. It creates convergence almost immediately
D. It uses the concept of send-only updates to routing tables. |
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Definition
| A. IS-IS is a link state dynamic protocol that is extremely similar to OSPF. The one major difference is that it was made with IPv6 in mind. |
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Term
Which one of these routing protocols is an exterior routing protocol? The rest are interior protocols. (pg. 262)
A. BGP
A. RIP
B. OSPF
C. IS-IS
D. EIGRP |
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Definition
| D. Enhanced Interior Gateway Routing Protocol |
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Term
___ is when a router takes routes it has learned by one method or protocol and announces those routes over another protocol. (pg. 262)
A. Route aggregation
B. Route preference
C. Route redistribution
D. Link state advertisement |
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Definition
| C. Route redistribution can come in handy when you have a mix of equipment and protocols in your network, such as occurs when you switch vendors or merge with another organization. |
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Term
Cable used to interface with a Cisco device. (pg. 263)
A. Yost cable
B. Parallel cable
C. Serial cable
D. Rollover cable |
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Definition
| A. or D. A Yost cable is used to make a special RJ-46-to-serial connection to a router, so it's not a conventional serial cable. It's also known as a rollover cable. |
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Term
Network devices that are extensively configurable. (pg. 264)
A. Managed devices
B. Modern hubs
C. Advanced switches
D. Routers |
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Definition
| A. Trick question, in a way. Advanced switches and routers are managed devices. No such thing as a "modern" hub. |
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Term
Software used to talk to and configure a network router. (pg. 264)
A. Router Interface Application
B. Driver
C. Terminal emulation program
D. Internetwork Operation System |
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Definition
| C. You'll need a terminal emulation program to configure a router from an operating system. |
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Term
Two common graphical terminal emulators are: (pg. 264)
A.Terminator
B. PuTTY
C. mintty
D. HyperTerminal |
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Definition
| B. and D. PuTTY and HyperTerminal |
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Term
True or false:
When packets aren't going to their intended destinations, the first place to look is the static routes on a routing table. (pg. 274) |
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Definition
True: For the most part, today's routers automatically generate directly connected routes, and dynamic routing takes care of itself.
Dynamic routing can encounter a convergence problem, but missing routes usually occur because you've forgotten to add them or made a typo in a static route. |
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Term
A single unit of information consisting of protocol control information and some form of data. (pg. 274)
A. Protocol data unit (PDU)
B. Frame data unit (FDU)
C. Packet transmission unit (PTU)
D. Maximum transmission unit (MTU) |
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Definition
| A. Each technology has a maximum size of a single PDU that can transmit, the maximum transmission unit (MTU). The other two terms don't exist. |
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Term
The protocol data unit (PDU) for Layer 4 is a(n) ___ that gets encapsulated into a(n) ___, the PDU for Layer 3. This in turn gets encapsulated in some medium at Layer 2, such as ____(s). (pg. 274)
A. TCP segment, Ethernet frame, IP packet
B. TCP segment, IP packet, Ethernet frame
C. IP packet, TCP segment, Ethernet frame
D. Ethernet frame, TCP segment, IP packet |
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Definition
A. Ethernet frames encapsulate packets, which encapsulates TCP segments.
IP packets work at the Network layer. Transport Control Protocol segments work at the Transport layer. Ethernet frames are created at the Data Link layer. |
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Term
The maximum size of a single protocol data unit (PDU) that can transmit. (pg. 274)
A. Total bandwidth
B. Maximum transmission unit (MTU)
C. Total payload
D. Full transmission cost (FTC) |
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Definition
| B. As each layer adds more info, the PDU gets larger, causing a packet or frame to exceed the MTU for the receiving system. This makes the network components split them into two or more pieces to get below the MTU threshold, causing fragmentation. |
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Term
Command line tool that records the route between any two hosts on a network for information and troubleshooting purposes. (pg. 275)
A. net use
B. traceroute
C. netscout
D. ping |
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Definition
B. Traceroute is something like a ping in that it sends a single packet to another host, but as it progresses, it returns information about every router between them.
Net use (dis)connects a computer from a shared resource, or displays information about computer connections.
NetScout is a network product vendor. |
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Term
At every hop, a router decreases the ___ number in a packet until the packet reaches its destination or hits zero. (pg. 276)
A. port
B. Network Address Translation (NAT)
C. time to live (TTL)
D. traceroute |
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Definition
| B. The TTL number stops packets from going on forever. The final router will discard the packet and send an ICMP to the original sender. |
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Term
Given the following routing table:
[image]
where would a packet with the address 192.168.0.17 be sent?
A. To the 192.168.0.0/24 network
B. To the 192.168.0.2555/32 network
C. To the default gateway, 192.168.0.5
D. The routing table doesn't have a route for that address |
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Definition
A. To the 192.168.0.0/24 network
A zero in a routing table means "anything", so any packet addressed to 192.168.0.x/24 will go to this network, excluding 192.168.0.255 because it has an entry in the table. |
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