Network users can't access the resources on the LAN attached to the e0 int of the production router. Which of the following commands will display current IP addressing and the Layer 1 and Layer 2 status of the interface? (Choose three)
A. Production# show interfaces
B. Production# show version
C. Production# show controllers
D. Production# show startup-config
E. Production# show ip interface
F. Production# show protocols
"show interfaces" is used to see the IP addresses and layer 2 information configured on the interfaces. "show controllers" is used to see the layer 1 stats. It tells about the V.35 cables: whether they are physically attached or not. "show interfaces" is used to see the IP add's configured on the interfaces.
- A. Production# show interfaces, E. Production# show ip interface, F. Production# show protocols
If all OSPF routers in a single area are configured with the same priority value, what value does a router use for the OSPF router ID in the absence of a loopback interface?
A. the IP address of the first Fast Ethernet interface
B. the highest IP address among its active interfaces
C. the lowest IP address among its active interfaces
D. the priority value until a loopback interface is config'd
Ordinarily the loopback interface would be selected as the router ID. In the event that no loopback interface is configured, the router ID will be the first active interface that comes up on the router. If that particular interface has more than one IP address, the highest address will be selected as the router ID.
- C. the lowest IP address among its active interfaces
In a switched environment, what does the IEEE 802.1Q standard describe?
A. the operation of VTP
B. a method of VLAN trunking
C. an approach to wireless LAN communication
D. the process for root bridge selection
E. VLAN pruning
- B. a method of VLAN trunking
- A broadcast domain must sometimes exist on more than one switch in the network. To accomplish this, one must send frames to another switch and indicate which VLAN a particular frame belongs to. On Cisco switches, a trunk line is created to accomplish this VLAN identification. ISL and IEEE 802.1Q are different methods of putting a VLAN identifier in a Layer 2 frame. the IEEE 802.1Q protocol interconnects VLANs between multiple switches, routers, and servers.
- With IEEE 802.1Q, a network admin can define a VLAN topology to span multiple physical devices. Cisco switches support IEEE 802.1Q for Fast Ethernet and Gigabit Ethernet interfaces.
- An IEEE 802.1Q trunk link provides VLAN identification by adding a 4-byte tag to an Ethernet Frame as it leaves a trunk port.
If an Ethernet port on a router was assigned an IP address of 172.16.112.1/20, what is the max number of hosts allowed on the subnet?
Given IP address 172.16.112.1/20, the subnet mask would be 255.255.240.0
How should a router that is being used in a Frame Relay network be configured to avoid split horizon issues from preventing routing updates?
A. Configure many sub-interfaces on the same subnet
B. Configure a single sub-interface to establish multiple PVC connections to multiple remote interfaces
C. Configure a separate sub-interface for each PVC with a unique DLCI and subnet assigned to the sub-interface
D. Configure each Frame-Relay circuit as a point-to-point line to support multicast and broadcast traffic
- C. Configure a separate subinterface for each PVC with a unique DLCI and subnet assigned to the sub-interface
- Point-to-Point Subinterfaces:
- The concept of subinterfaces was originally created in order to better handle issues caused by split-horizon over Non-Broadcast Multiple Access (NBMA) networks (e.g. frame relay, X.25) and distance-vector based routing protocols (e.g. IPX RIP/SAP, Appletalk). Split-horizon dictates that a routing update received on an interface cannot be retransmitted out onto the same interface. This rule holds even if the routing update was received on one frame relay PVC and destined to retransmit out onto another frame relay PVC. Referring to figure 2, this would mean that sites B and C can exchange routing information with site A, but would not be able to exchange routing information with each other. Split-horizon does not allow site A to send routing updates received from site B on to site C and vice versa.
Note: for TCP/IP, Cisco routers can disable split-horizon limitations on all frame relay interfaces and multipoint subinterfaces and do this by default. However, split-horizon cannot be disabled for other protocols like IPX and AppleTalk. These other protocols must use subinterfaces if dynamic routing is desired.
By dividing the partially-meshed frame relay network into a number of virtual, point-to-point subinterfaces, the split-horizon problem can be overcome. Each new point-to-point subnetwork is assigned its own network number. To the routed protocol, each subnetwork now appears to be located on separate interfaces. Routing updates received from site B on one logical point-to-point subinterface can be forwarded to site C on a separate logical interface without violating split-horizon.
Which connections allow the use of full-duplex Ethernet? (Choose three)
A. switch to hub
B. switch to host
C. hub to hub
D. switch to switch
E. host to host
- B. switch to host
- D. switch to switch
- E. host to host
- Full-duplex Ethernet uses two pairs of wires, instead of one pair like half-duplex. And full duplex uses a point-to-point connection between the transmitting device and the receiving device. This means that w/full duplex you get a faster data transfer. And because data is sent/received on different sets of wire, no collisions occur.
Which command will set the default gateway to 192.168.12.1?
A. Switch(config)# ip route 192.168.12.1 0.0.0.0
B. Switch(config)# ip default-network 192.168.12.1
C. Switch(config)# ip route-default 192.168.12.1
D. Switch(config)# ip default-gateway 192.168.12.1
- D. Switch(config)# ip default-gateway 192.168.12.1
- IP default-gateway address is a global command that sets the default gateway so the mgmt interface can be reached from a remote network. [CCNA ICND p.14]
Which of the following are characteristics of a Frame Relay point-to-point subinterface? (choose two)
A. resolves NBMA split horizon issues
B. requires the frame-relay map command
C. maps one IP subnet per DLCI
D. maps one IP subnet across multiple DLCIs
E. requires use of Inverse-ARP
- A. resolves NBMA split horizon issues , C. maps one IP subnet per DLCI
- Frame relay networks fall under the umbrella of Non-Broadcast Multi-Access (NBMA) networks. As the name implies, these networks allow multiple devices to access the network, but do not allow broadcasts btwn them. Altho this is default behavior, you can config the router to treat the network however you like. Because NBMA networks allow traffic btwn only the sites for which you purchase PVCs, this leads to some very odd configs. The hub and spoke topology can be very confusing to manage until you understand the problems with these network types. One of the major problems is that of running distance vector routing protocols over a frame relay network. These protocols (RIP, IGRP, EIGRP) have split-horizon.
At which layer of the OSI model does the protocol that provides the information displayed by the show cdb neighbors command operate?
E. data link
- E. data link
- CDP is a device discovery protocol that runs over Layer 2 (data link) on all Cisco gear and allows network mgmt apps to discover Cisco devices that are neighbors of already known devices. With CDP, net. mgmt app's can learn the device type and SNMP agent address of neighbor devices running lower layer, transparent protocols.
In the implementation of VLSM techniques on a network using a single Class C IP address, which subnet mask is the most efficient for point-to-point serial links?
only 2 IPs are required. duh!
What are the three valid reasons to assign ports to VLANs on a switch? (choose three)
A. to increase the size of the collision domain
B. to make VTP easier to implement
C. to logically group hosts according to function
D. to allow more devices to connect to the network
E. to isolate broadcast traffic
F. to increase network security
- C. to logically group hosts according to function, E. to isolate broadcast traffic, F. to increase network security
- Main functions of a VLAN: can group several broadcast domains into multiple logical subnets. You can accomplish network additions, moves, and changes by configuring a port into the appropriate VLAN. You can place a group of users who need high security into a VLAN so that no users outside of the VLAN can communicate with them. As a logical grouping of users by function, VLANs can be considered independent from their physical/geographical locations. VLANs can enhance security, and increase number of broadcast domains while decreasing their size.
Which of the following describe private IP addresses? (choose two)
A. addresses that can be routed through the public internet
B. addresses chosen by a company to communicate with the internet
C. addresses licensed by enterprises or ISPs by an Internet registry organisation
D. a scheme to conserve public addresses
E. addresses that cannot be routed through the public internet
- D. a scheme to conserve public addresses, E. addresses that cannot be routed through the public internet
- Private IP address space has been allocated via RFC 1918. This means the addresses are available for use by anyone and therefore the same private IP addresses can be reused.
When VLSM is used, what does the term route aggregation describe?
A. combining routes to multiple networks into one supernet
B. reducing the number of unusable addresses by creating many subnets from one supernet
C. reclaiming unused address space by changing the subnet size
D. calculating the total number of available host addresses in the AS
Route aggregating is combining routes to multiple networks into one. AKA route summarization or supernetting. Normally used to reduce the number of route entries in the routing table by advertising numerous routes into one larger route.
- A. combining routes to multiple networks into one supernet
A network admin needs to allow only one telnet connection to a router. For anyone viewing the config and issuing the show run command, the password for telnet access should be encrypted. What are the commands for this?
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. service password-encryption, line vty 1, login, password cisco
C. enable password secret, line vty 0, login, password cisco
D. service password-encryption, line vty 0 4, login, password cisco
B. service password-encryption, line vty 1, login, password cisco
Why would a network admin configure port security on a switch?
A. to block unauthorized access to the switch mgmt interfaces over common TCP ports
B. to limit the number of L2 broadcasts on a particular switch port
C. to prevent unauthorized Telnet access to a switch port
D. to prevent the IP and MAC addresses of the switch and associated ports
E. to prevent unauthorized hosts from accessing the LAN
- E. to prevent unauthorized hosts from accessing the LAN
What is the advantage of using a multiport interface instead of point-to-point subinterfaces when configuring a Frame Relay hub in a hub-and-spoke topology?
A. It avoids split-horizon issues with distance vector routing protocols
B. IP addresses can be conserved if VLSM is not being used for subnetting
C. the multiple IP network addresses required for a multipoint interface provide greater addressing flexibility over point-to-point configs
D. a multipoint interface offers greater security compared to point-to-point subinterface configs
- B. IP addresses can be conserved if VLSM is not being used for subnetting
- Frame relay supports two types of interfaces: point-to-point and multipoint. The one you choose determines whether you need to use the config commands that ensure IP address to datalinkconnection identifier (DLCI) mappings. After configuring the PVC itself, you must tell the router which PVC to use in order to reach a specific destination. Use the frame-relay interface-dlci command to assign a DLCI to a specified Frame Relay subinterface.
What is the purpose of this command? vtp password F|0r1da
A. used to access the VTP server to make changes to the VTP configuration
B. allows two VTP servers to exist in the same domain, each configured with different passwords.
C. used to prevent a switch newly added to the network from sending incorrect VLAN info to the other switches in the domain
D. its the password required when promoting a switch from VTP client mode to VTP server mode
E. used to validate the sources of VTP advertisements sent btwn switches
- E. used to validate the sources of VTP advertisements sent btwn switches
- VTP passwords help to authenticate the VTP clients as members of the same VTP domain, while authenticated VTP servers start advertisements to VTP clients. The VTP password and domain should be the same for both the VTP server and client.
All WAN links outside the ABC University network use PPP with CHAP for authentication security. Which command will display the CHAP authentication process as it occurs btwn two routers in the network?
A. show ppp authentication chap
B. show interface serial0
C. debug PPP authentication
D. show CHAP authentication
E. debug CHAP authentication
- C. debug PPP authentication
- Whenever you're asked to display a process in real time, you must use a debug command as show commands do not display anything in real time. This command will display the authentication process of a PPP line, including the CHAP process.
Which two statements are true about the command ip route 172.16.3.0 255.255.255.0 192.168.2.4? (choose two)
A. It configs the router to send any traffic for an unknown destination out the interface with the address 192.168.2.4
B. It establishes a static route to the 192.168.2.0 network
C. It is a route that would be used last if other routes to the same destination exist
D. It uses the default admin distance
E. It configs the router to send any traffic for an unknown destination to the 172.16.3.0 network
F. It establishes a static route to the 172.16.3.0 network
- D. It uses the default admin distance
- F. It establishes a static route to the 172.16.3.0 network
Which statement describes a spanning-tree network that has converged?
A. All switch and bridge ports are assigned as either root or designated ports
B. All switch and bridge ports are in the forwarding state
C. All switch and bridge ports are in either the forwarding or blocking state
D. All switch and bridge ports are either blocking or looping
- C. All switch and bridge ports are in either the forwarding or blocking state
- When a switch first comes up, it will be in the listening and learning states. This is needed so that the switch learns the MAC address of the devices on the LAN, and to learn where any loops in the network may exist. After this initial period, the ports will be forwarding to the hosts or blocking certain ports that create a loop.
A Static route to the 10.5.6.0/24 network is to be configured on the HFD router. The administrator wants HFD to see this static route as the most reliable route. Which command should the admin use?
A. HFD(config)# ip route 10.5.6.0 0.0.0.255 10.5.4.6
B. HFD(config)# ip route 10.5.6.0 255.255.255.0 10.5.4.6
C. HFD(config)# ip route 10.5.6.0 0.0.0.255 fa0/0
D. HFD(config)# ip route 10.5.4.6 255.255.255.0 10.5.6.0
E. HFD(config)# ip route 10.5.4.6 0.0.0.255 10.5.6.0
F. HFD(config)# ip route 10.5.6.0 255.255.255.0 fa0/0
- C. HFD(config)# ip route 10.5.6.0 0.0.0.255 fa0/0, D. HFD(config)# ip route 10.5.4.6 255.255.255.0 10.5.6.0, F. HFD(config)# ip route 10.5.6.0 255.255.255.0 fa0/0
- There are two ways to specify a default static route. One is to specify the interface to use for forwarding packets, like in answer C. The other way is to specify the IP address of the next hop router, as in answer D.
- The following command string is used to add a static route to the routing table:
- ip route [dest network] [mask] [next hop address or exit interface] [administrative distance] [permanent]
- This list describes each command in the string:
- ip route - command to create static route
- destination network - network placed in the routing table
- mask - subnet mask used
- next hop address - next hop router's address that will receive packet and forward to remote network.
- (default admin dist = 1)