Networking Concepts (4) Flashcards
Which of the following TCP/IP routing protocols does not include the subnet mask within its route update messages, preventing it from supporting subnetting?
Routing Information Protocol, version 1 (RIPv1)
Routing Information Protocol, version 2 (RIPv2)
Border Gateway Protocol (BGP)
Routing Information Protocol, version 1 (RIPv1)
RIP v1 does not include the subnet mask in its updates. RIPv2 supports subnetting and includes the subnet mask of each network address in its updates. OSPF and BGP both include the subnet mask within their updates
Which of the following terms refers to a routing protocol that does not rely on hop counts to measure the efficiency of routes?
Edge gateway protocol
Distance vector protocol
Link state protocol
Link state protocol
Distance vector protocols rely on hop counts to evaluate the efficiency of routes. Link state protocols use a different type of calculation, usually based on Dijkstra’s algorithm. The terms interior gateway protocol and edge gateway protocol do not refer to the method of calculating routing efficiency
What is the maximum number of routes that can be included in a single RIP broadcast packet?
20
25
32
25
A single RIP broadcast packet can include up to 25 routes. If there are more than 25 routes in the computer’s routing table, then RIP must generate additional packets
Which of the following routing protocols can you use on a TCP/IP internetwork with segments running at different speeds, making hop counts an inaccurate measure of route efficiency? (Choose all correct answers.)
Enhanced Interior Gateway Routing Protocol (EIGRP)
Routing Information Protocol (RIP)
Open Shortest Path First (OSPF)
Border Gateway Protocol (BGP)
Enhanced Interior Gateway Routing Protocol (EIGRP)
Open Shortest Path First (OSPF)
OSPF is a link state routing protocol, which means that it does not rely solely on hop counts to measure the relative efficiency of a route. EIGRP is a hybrid protocol that can use link state routing. RIP is a distance vector routing protocol, meaning that it uses hop counts to measure route efficiency. BGP is an exterior gateway protocol that exchanges routing information among autonomous systems using path vectors or distance vectors
What is the term for the process by which dynamic routing protocols update other routers with routing table information?
Convergence
Distance vectoring
Redistribution
Convergence
Convergence is the term for the process by which routers propagate information from their routing tables to other routers on the network using dynamic routing protocols. Distance vectoring, redistribution, and dissemination do not describe this process
Which of the following are terms for an area of an enterprise network, separated by firewalls, that contains servers that must be accessible both from the Internet and from the internal network? (Choose all correct answers.)
DMZ
EGP
Stateless network
Perimeter network
DMZ
Perimeter network
Servers that must be accessible both from the internal network and from the Internet are typically located in an area of the enterprise called a perimeter network or a demilitarized zone (DMZ). This area is separated from both the Internet and the internal network by firewalls, which prevents unauthorized internet users from accessing the internal network. Intranet is another term for the internal network. Edge Gateway Protocol (EGP) is a type of routing protocol, and stateless is a type of firewall; neither applies to this definition
Each of the following Carrier Sense Multiple Access with Collision Detection (CSMA/CD) events occurs on an Ethernet network when two stations transmit simultaneously, although not in the order listed. Which of the following events occurs immediately after the collision?
The two stations observe a random back-off interval.
The two stations transmit a jam signal.
The two stations stop transmitting.
The two stations stop transmitting.
Stations on a CSMA/CD network first check the medium to see if it’s idle. If they detect an idle medium, they begin transmitting. If two or more devices transmit at the same time, a collision occurs. Immediately after a collision occurs, the two stations involved stop transmitting and then send out a jam signal. Then, the two stations back off for a random interval, and the transmission process begins again
Which of the following TCP/IP routing protocols measures the efficiency of routes by the number of hops between the source and the destination?
Routing Information Protocol (RIP)
Open Shortest Path First (OSPF)
Border Gateway Protocol (BGP)
Routing Information Protocol (RIP)
RIP is a distance vector protocol, which uses hop counts to measure the efficiency of routes. OSPF, BGP, and IS-IS are all link state protocols, which do not rely on hop counts
Which of the following IEEE standards calls for the use of the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) media access control mechanism?
- 11ac
- 1X
- 3
802.11ac
The IEEE 802.11ac standard, like all of the wireless LAN standards in the 802.11 working group, uses CSMA/CA for media access control. The 802.1X standard defines an authentication mechanism and does not require a media access control mechanism. The IEEE 802.3 (Ethernet) standard uses Carrier Sense Multiple Access with Collision Detection (CSMA/CD)
Which of the following devices is used to physically connect computers in the same VLAN?
A bridge
A hub
A switch
A switch
Replacing routers with switches turns an internetwork into a single large subnet, and virtual local area networks (VLANs) exist as logical elements on top of the switching fabric. Although VLANs are the functional equivalent of network layer subnets, the systems in a single VLAN are still physically connected by switches, not routers. Bridges connect network segments at the data link layer and selectively forward traffic between the segments. However, bridges do not provide a dedicated connection between two systems like a switch does, and they do not make it possible to convert a large routed internetwork into a single switched network. Therefore, they have no role in implementing VLANs. Hubs are physical layer devices that propagate all incoming traffic out through all of their ports. Replacing the routers on an internetwork with hubs would create a single shared broadcast domain with huge amounts of traffic and many collisions. Hubs, therefore, do not connect the computers in a VLAN
Which of the following statements is true about an Ethernet network that uses CSMA/CD?
Collisions are a normal occurrence.
Collisions never occur unless there is a network fault.
Collisions cause data to be irretrievably lost.
Collisions are a normal occurrence.
Collisions are a normal occurrence on an Ethernet network; they occur when two nodes transmit at exactly the same time. There need not be a network fault for collisions to occur. When collisions occur, the nodes involved retransmit their packets so that no data is lost. Collisions are a phenomenon of data link layer protocols; they have nothing to do with IP addresses, which are network layer constructs
VLANs create the administrative boundaries on a switched network that are otherwise provided by which of the following devices?
Hubs
Routers
Domains
Routers
Connecting subnets with routers at the network layer maintains the data link layer administrative boundaries that prevent broadcast transmissions from being propagated throughout the entire internetwork. Switching eliminates those data link layer boundaries, and administrators can use virtual local area networks (VLANs) to simulate them. Because hubs propagate all of the traffic they receive out through all of their ports indiscriminately, they create no administrative boundaries. Domains are logical groups of network devices defined by the Domain Name System (DNS). Their functions are not related to VLANs in any way. Switches are essentially multiport bridges that forward incoming traffic only to the device for which it is destined. Therefore, bridges are more closely related to eliminating administrative boundaries than to establishing them
Which of the following statements about VLANs are true? (Choose all correct answers.)
All of the devices in a particular VLAN must be physically connected to the same switch.
A VLAN creates a limited broadcast domain on a switched network.
You must have VLANs on a switched network for communication between computers on different cable segments to occur.
A router is required for communication between VLANs.
A VLAN creates a limited broadcast domain on a switched network.
A router is required for communication between VLANs.
The computers in a single virtual local area network (VLAN) can be located anywhere on a switched network, irrespective of the switches’ physical configuration. A broadcast message generated by a computer in a VLAN is transmitted to all of the other computers in that VLAN only, just as if the systems were physically located on a separate LAN or subnet. Unicast transmissions between computers on a switched network do not require VLANs because the switches create what amounts to a direct connection between the two systems. VLANs are needed only for communication processes that require the use of broadcasts, which if transmitted without VLANs, would flood the network. Even though they are a purely logical construction, VLANs function just like physical subnets and require routers for communication between them. Routing capabilities are often integrated into switches to enable communication between VLANs
Which of the following elements can be used to identify the devices in a particular VLAN? (Choose all correct answers.)
Hardware addresses
IP addresses
DNS names
Switch port numbers
Hardware addresses
Switch port numbers
Every network device has a unique hardware address coded into its network interface adapter, and administrators can use these addresses to select the devices that will be part of a specific virtual local area network (VLAN). When VLANs are implemented inside the switch, selecting the ports to which specific computers are attached is a simple way to identify the computers in a particular VLAN. IP addresses are layer 3 (network layer) constructs, so they do not apply to layer 2 (data link layer) devices like switches. Although DNS names do uniquely identify computers on a network, DNS is an application layer process and has nothing to do with the switching and routing processes, which occur at the data link and network layers. Therefore, you cannot use DNS names to identify the computers in a VLAN
Network address translation (NAT) operates at which layer of the Open Systems Interconnection (OSI) model?
Data link
Network
Transport
Network
NAT works by modifying IP addresses, which are a network layer element. The data link layer is concerned only with communications on the local subnet and is not involved with NAT processing. Because NAT modifies only the IP packet headers, it works with any transport layer protocol. NAT also works with most TCP/IP applications because it operates below the application layer of the OSI model
