*Which of the following is true of Multiprotocol Label Switching? (Select two.)
- CEF is required for all MPLS-enabled Cisco routers.
- MPLS-enabled routers switch packets based on the packet contents, not on label information.
- MPLS can carry ATM, SONET, and Ethernet traffic.
- Packets routed using MPLS require additional routing lookup overhead.
- MPLS is designed to forward only packets created with the TCP/IP protocol.
- CEF is required for all MPLS-enabled Cisco routers
- MPLS can carry ATM, SONET, and Ethernet traffic.
Key facts about Multiprotocol Label Switching (MPLS) include the following:
- MPLS can carry ATM, SONET, and Ethernet traffic.
- CEF is required for all MPLS-enabled Cisco routers.
- Packets are routed with a minimal amount of routing lookup overhead.
- MPLS-enabled routers switch packets based on the label information, not on the packet contents.
- MPLS is designed to support forwarding of protocols other than TCP/IP.
*When implementing a Multiprotocol Label Switching (MPLS) WAN, which data unit is managed by the routers at different sites?
- Frames
- Packets
- Datagrams
- Bits
-Packets
In a Multiprotocol Label Switching (MPLS) WAN, IP packets are forwarded between sites. Packets are forwarded based on the contents of the label, without examination of the packet. This allows the creation of end-to-end circuits across any type of WAN transport medium using any protocol.
Which VSAT component provides data transmission capabilities over a satellite link?
- Indoor unit (IDU)
- Block Upconverter (BUC)
- Orthomode transducer (OMT)
- Low-noise Block Downconverter (LNB)
-Block Upconverter (BUC)
A VSAT implementation consists of the following components:
- Block Upconverter (BUC) for transmitting data.
- Antenna.
- Low-noise Block Downconverter (LNB) for receiving data.
- Orthomode transducer (OMT) to combine and/or separate two microwave signals.
- Interfacility link cable (IFL).
- Indoor unit (IDU) to provide an interface to the organization’s network using two physical connections:
- One Ethernet port that provides an interface for the organization’s internal router.
- Two F-type connectors that connect to the BUC and the LNB on the dish.
Which of the following describe the channels and data transfer rates used for ISDN BRI? (Select two.)
- Two channels operating at 64 Kbps each
- 23 channels operating at 64 Kbps each
- One channel operating at 16 Kbps
- One channel operating at 64 Kbps
- 11 channels operating at 64 Kbps
Two channels operating at 64 Kbps each
One channel operating at 16 Kbps
ISDN BRI uses two channels operating at 64 Kbps and one channel operating at 16 Kbps. It is often called 2B + 1D
*Which of the following services are available regardless of whether the telephone company network is available?
- ISDN
- DSL
- Cable modem
- Dial-up
-Cable modem
EXPLANATION
A cable modem is a network connectivity service provided by the cable television service provider. Cable modem operates by adding a bi-directional channel connected directly to an internet service provider through cable TV lines. It does not depend on phone lines for the connection.
*Which WAN connection types use digital communications over POTS? (Select two.)
- SONET
- X.25
- ISDN
- 56 Kbps dialup
- ATM
- DSL
- ISDN
- DSL
EXPLANATION
Both DSL (Digital Subscriber Line) and ISDN (Integrated Services Digital Network) use regular phone lines (POTS) for digital communications.
56 Kbps dial-up uses analog signals over regular phone lines. X.25 can use either digital or analog signaling, but uses analog signaling when implemented over standard telephone lines. SONET operates over fiber optic cables. ATM uses fixed-length cells for transmitting data over a variety of media (twisted pair and fiber optic being the most common).
*Match each WAN topology to its description. Each topology will only be used once.
A) Connects multiple network locations to each other via WAN links. Each location has a direct link to all other locations.
B) A single, pre-established path from one network location, through a carrier network, and to a remote network location.
C) Connects multiple remote networks via WAN links. One site is the main location.
D) Provides two separate physical connects to a single ISP.
E) A network connected to an ISP using a single line.
- Hub and spoke
- Full mesh
- Single-homed
- Point-to-point
- Dual-homed
A/2
B/4
C/1
D/5
E/3
Which switching network type allows data connections that can be initiated when needed and terminated when communication is complete?
- Hub and spoke
- Packet
- Circuit
- Point-to-point
Circuit
A circuit switching network allows data connections that can be initiated when needed and terminated when communication is complete. It works much like a telephone line works for voice communication. A circuit switched network uses a dedicated connection between sites. It is ideal for transmitting data that must arrive quickly and in the order it is sent, as is the case with real-time audio and video.
*Which of the following is an example of a public WAN?
Cable internet
Leased lines
MPLS
ISDN
Cable internet
A public WAN (such as the internet) allows access to any number of sites outside the private network. The communication lines are not protected, and the entity initiating the communication is responsible for the security of the data. Public WAN connections can include:
Cable internet
Public Switched Telephone Network (PSTN), which uses the internet
ISDN, which uses the internet
Cellular
DSL
A private WAN allows a site to connect to one or more designated sites using communication methods that maintain the privacy of the data being transferred. Private WANs typically use the following types of WAN technologies to connect sites:
Integrated Services Digital Network (ISDN)
Leased lines
Ethernet WANs
Multiprotocol Label Switching (MPLS)
Very Small Aperture Terminal (VSAT)
Which cellular network type can, theoretically, provide speeds up to 10Gbps?
- 5G
- 2G
- 3G
- 4G
-5G
5G offers speeds up to 10Gbps. 5G cellular networks is the latest standard. It is now available, and coverage is expanding.
2G (second generation) networks were the first to offer digital data services. 2G data speeds are slow (14.4 Kbps) and are used mainly for text messaging, not internet connectivity.
3G offers simultaneous voice and data. Minimum speeds for stationary users are quoted at 2 Mbps or higher.
4G is available with minimum speeds around 3 Mbps, with over 100 Mbps possible.
*Which is the default Layer 2 encapsulation method for serial interfaces on a Cisco router?
- Ethernet
- HDLC
- PPP
- Frame Relay
HDLC
The High-Level Data Link Control (HDLC) WAN protocol is the default encapsulation method configured on Cisco serial interfaces.
Point-to-Point (PPP) and Frame Relay are two other common WAN encapsulation methods used on synchronous serial connections, but neither of them are the default. Ethernet is a LAN protocol and cannot be configured on serial interfaces.
*Drag each leased line component on the left with its corresponding description on the right. Each component may be used once, more than once, or not at all.
- Connects the WIC in the router to the telecom equipment.
- Controls the speed and timing of the router’s serial interfaces.
- Provides the clocking function on the link.
- The equipment at the customer site.
- Provides a Layer 1 interface between the router and the telecom provider’s equipment.
Serial cable
CPE
CSU/DSU
Connects the WIC in the router to the telecom equipment.
Serial cable
Controls the speed and timing of the router’s serial interfaces.
CSU/DSU
Provides the clocking function on the link.
CSU/DSU
The equipment at the customer site.
CPE
Provides a Layer 1 interface between the router and the telecom provider’s equipment.
CSU/DSU
Which of the following is true regarding WAN leased lines?
- The speed is symmetric.
- Provides a data-link layer transmission facility.
- Each router runs in half-duplex.
- Each router runs in full-duplex.
- The speed is asymmetric.
- The speed is symmetric.
- Each router runs in full-duplex.
The following are facts about WAN leased lines.
- Each router runs in full-duplex.
- The speed is symmetric, meaning that both routers send bits at the same speed.
- The lease line provides a physical layer bit transmission facility:
- Routers require a data link protocol on the WAN link.
- The lease line itself does not define a Data Link layer protocol to be used.
*What is the removable card that contains the serial interface on a router called?
- CPE
- CSU
- WIC
- HDLC
WIC
Serial interfaces on the router are typically a removable card called a WAN interface card (WIC).
The CSU is a device that provides the clocking function. This function physically controls the speed and timing that the router’s serial interfaces use to send and receive bits over the serial cable.
The CPE is the equipment at the customer site.
HDLC is often used as the data link protocol for WAN leased line connections.
*Which of the following is a type of line supported by a leased line?
- T1
- T5
- T4
- T2
- T3
T1
T3
*You are configuring a serial connection and need to configure the DCE to provide a clocking signal.
Given that you have leased a 128 Kbps line from the WAN service provider, which command should you use to accomplish this task?
-clock rate 128
-clock rate 128000
-clock 128000
-encapsulation hdlc 128
clock rate 128000
The clock rate command sets the clock rate on the DCE serial interface. When you issue this command, you need to specify the clock speed to use in bits per second. Because a 128-Kbps link has been leased from the WAN service provider, the speed of the link should be set to approximately 128000 bps.
*You are troubleshooting problems with a serial interface on a router that is connected to a leased line WAN interface.
You need to view the type of serial cable that has been used on the s0/0/1 interface and which end of the cable is connected to the DCE or DTE.
Which command should you use to do this?
s-h ip interface brief
-sh controllers s0/0/1
-sh run
-sh interfaces
-sh controllers s0/0/1
The sh controllers s0/0/1 command displays the serial interface configuration, such as the type of serial cable and which end of the cable is connected to the device (DCE or DTE).
You need to assign an interface on the router with the IP address 192.168.1.250 and subnet mask of 255.255.255.0.
Which command will accomplish this task?
-ip address 192.168.1.250 255.255.255.0
-ip address 192.168.1.250 / 255.255.255.0
-ip address mask 192.168.1.250 255.255.255.0
-ip address 255.255.255.0 192.168.1.250
-ip address mask 192.168.1.250 255.255.255.0
*What is the router that provides clocking when connecting two routers in a back-to-back configuration through their serial ports called?
- WIC
- DTE
- CPE
- DCE
DCE
The router providing clocking is known as the Data Communications Equipment (DCE).
Which command will allow you to see a consolidated message about each IP interface?
-sh controllers
-sh run
-sh interfaces
-sh ip int brief
-sh ip int brief
The sh ip int brief command displays a consolidated message about each IP interface, including its IP address, line and protocol status, and how the address was configured (DHCP or Manual).
*Which of the following is a benefit of using network address translation (NAT)?
- NAT provides a measure of network security.
- Broadcast traffic domains can be defined at Layer 2.
- It eliminates the need for routing.
- Remote hosts can access the corporate network through a secure tunnel.
-NAT provides a measure of network security.
Network address translation offers the following benefits:
- The internal hosts on the private network do not advertise their addresses or internal topology externally, so NAT is a type of firewall strategy that protects network security.
- NAT eliminates the need to re-address hosts that require external network access, which saves time and money.
- With NAT, internal hosts can share a single registered IP address for all external communications, so few external addresses are required to support many internal hosts. This conserves IP addresses.
*You have a small network as shown. Router2 is connected to the internet through a fiber optic FastEthernet connection and will be configured with NAT to provide internet connectivity to your private network.
What type of address would you assign to the Fa0/1 interface on Router2?
- Inside global
- Outside global
- Outside local
- Inside local
Outside global
The interface that connects the NAT router to the internet is assigned an outside global IP address. This is a public IP address that is registered and recognized on the internet.
*You are designing a new network that will support 6,000 computers. You only have eight registered IP addresses that can be allocated to the employees for external network communication, so you decide to implement NAT and share the addresses. You want all of these computers to be able to access the internet at the same time if necessary.
Which method of NAT translation should you implement?
- Overloading
- Static
- Restricted
- Dynamic
Overloading
You should implement the overloading method of network translation because it allows multiple internal hosts to share a single or several registered IP addresses by using a unique source port number on the inside global address to distinguish between translations.
*You have a small network connected to the internet as shown.
Which of the following statements is true? (Select two.)
- Internet hosts can reach Srv2 without NAT.
- Internet hosts can reach Srv1 without NAT.
- The router must be configured for NAT for Srv2 to communicate on the internet.
- The router must be configured for NAT for Srv1 to communicate on the internet.
- The router must be configured on all interfaces with NAT.
- Internet hosts can reach Srv2 without NAT.
- The router must be configured for NAT for Srv1 to communicate on the internet.
The subnet connected to Fa0/0 is using private IP addressing; therefore, NAT must be configured before Srv1 can communicate on the internet. The subnet connected to Fa0/1 is using public addressing; therefore, NAT is not required.
