Network Fundamentals Flashcards
The headquarter router receives a packet with the destination address 192.168.4.127/25 on its fast Ethernet port 0. What actions will the router take regard to the packet?
A. It will add a source address to the packet before routing further.
B. It will forward the packet to the next hop.
C. It will discard the packet.
D. It will add a TCP header before forwarding the packet to the next destination.
C. It will discard the packet.
The router will discard any packet with the destination address 192.168.4.127/25.
The IP address 192.168.4.127 is a broadcast address. A router, by default, discards broadcast packets. The IP address 192.168.4.127/25 has a subnet mask, 255.255.255.128, which defines the block size as 128, so there will be two subnets, 0 and 128. The IP addresses 192.168.4.0 and 192.168.4.128 are subnet IDs, whereas 192.168.4.127 and 192.168.4.255 are broadcast addresses.
A network administrator needs to select hardware for a new branch office. The office will be divide into three parts for three teams, and each will have a separate subnet. The network assigned for the finance team, sales team, and accounts team devices are 192.168.10.0/26, 172.168.170.0/27 and 10.6.8.0/28, respectively. Which device should the network administrator select to ensure smooth communication?
A. Hub
B. Router
C. Switch
D. Bridge
B. Router
The administrator should select a router for communication between all devices. A router helps connect different sets of subnets. It operates at layer 3 of the OSI Model and makes all the routing decisions based on IP addresses. A router creates a routing table, which is used to forward packets to the next destination. By default, routers don’t forward broadcast. They are also used for filtering network-related information and path selection based on IP addresses.
The employees at a company head office are unable to access the Internet due to network failure. The network engineer finds that the router’s serial interface status shown is ‘down’. In which layer of the OSI Model has the problem occurred? The router shows the interface command as follows:
Serial0/1 is down, line protocol is down
Hardware is GT9K Serial
Description: WAN Link to Exeter
Interface is unnumbered, Using address of FastEthernet0/0 (172.16.6.234)
MTU 1500 bytes, BW 2048 Kbit, DLY 20000 usec,
reliability 255/255, txload 25/255, rxload 5/255
Encapsulation PPP, LCP Open
Open: CDPCP, IPCP, loopback not set
Last input 00:00:00, output 00:00:03, output hang never
A. Transport layer
B. Data layer
C. Physical layer
D. Network layer
C. Physical layer
The problem has occurred in the physical layer of the OSI Model as the Serial0/1 interface status is ‘down’. The first parameter refers to the physical layer, which is ‘down’. If the Serial0/1 interface status shows ‘up’ it means the line protocol is down and there is a Data Link layer problem.
What are the best Ethernet cabling standards that supports a maximum length of 100 meters? (Choose all that apply)
A. 10BASE-T
B. 10GBASE-T1
C. 1000BASE-T
D. 1000BASE-SX
A. 10BASE-T
C. 1000BASE-T
10BASE-T and 1000BASE-T are the Ethernet standards that support a maximum length of 100 meters. The cable type used for 10BASE-T and 1000BASE-T is UTP, 10GBASE-T1 supports a maximum segment length of 38-to-55 meters, whereas 1000BASE-SX supports up to 550 meters. Ethernet standards are selected based on parameters such as speed and maximum distance allowed between the devices using standard cabling.
Which command needs to be configured to use only link-local address for an IPv6 network?
A. ipv6 enable
B. ipv6 link-route enabled
C. ipv6 neighbor
D. ipv6 unicast-routing
A. ipv6 enable
The ‘ipv6 enable’ command needs to be configured to use only link-local address for an IPv6 network. If a customer has only a link-local address, the person will be able tp communicate only through that local subnet.
A network engineer needs to set up a new office in California. The network devices at the new office should be connected in such a way that they provide fault tolerance and full redundancy. Which topology should be used to achieve this?
A. Star
B. Hybrid
C. Mesh
D. Ring
C. Mesh
The mesh topology should be used while setting up a new office to provide fault tolerance and full redundancy for the network.
The full mesh topology is a design that creates a link between all pairs of nodes, whereas the partial mesh topology is used to connect a link between some pairs of nodes.
A remote site is San Jose is experiencing a broadcast storm in the local network. What devices should be used to break the broadcast? (Choose all that apply)
A. Bridge
B. Layer 3 Switch
C. Router
D. Access Point
B. Layer 3 Switch
C. Router
To break a broadcast storm, the router and layer 3 switches need to be used. Routers, by default, don’t forward broadcast and are used only to break a collision domain. A layer 3 switch is used for IP routing. For intra-VLAN communication, the layer 3 switch uses the MAC address table, whereas for inter-VLAN communication, it uses the IP routing table.
To enable IPv6 on a router, which global configuration command needs to be configured by the network administrator?
A. ipv6 enable
B. ipv6 neighbor
C. ipv6 cdp enable
D. ipv6 unicast-routing
D. ipv6 unicast-routing
To enable IPv6 on a router, an administrator needs to configure that ipv6 unicast-routing global command. IPv6 traffic forwarding is disabled on the default router. The administrator needs to enable it using ipv6 unicast-routing command under global configuration mode.
What command needs to be used to migrate a configuration from HDLC to PPP?
A. encapsulation ppp
B. ppp authentication chap
C. ppp multilink group
D. enable ppp
A. encapsulation ppp
The “encapsulation ppp” command needs to be used to migrate a configuration from HDLC to PPP. Point-to-Point Protocol (PPP) is a data link protocol used on serial links. It supports both synchronous and asynchronous links. The “show interface” command is used to list PPP details.
What information does a network layer packet contain? (Choose all that apply)
A. TCP or UDP
B. IP
C. Data
D. Link header, data, and link trailer
A. Data
D. IP
A packet contains IP and data information. A packet is defined to work at a network layer, and any information after the IP header is referred to as data. The TCP/IP messages are referred to as segment, packet, or frame, depending on the layer they work.
A network engineer needs to design a new setup for an HQ site, which consists of 1000 hosts and and 40 network devices connected between three buildings. The hierarchical internetwork design should be scalable, reliable, and cost-effective. Which option will help the network engineer achieve the design of the new setup?
A. Use the hybrid topology for a connection of network devices.
B. Use the three-tier architecture.
C. Connect the network devices in the mash topology for redundancy.
D. Use the two-layer model.
B. Use the three-tier architecture
The network engineer should use a three-tier architecture to design the setup of a new HQ office consisting of 1000 hosts and 40 network devices connected between three buildings.
The three-tier architecture is a scalable, reliable, and cost-effective solution. The three layers in the hierarchical model are core, disturbance, and access. The core level is responsible for forwarding a larger volume of traffic with high speed and reliable connectivity. The distribution layer is used for routing between access layer switches. User endpoints are not directly connected to distribution switches. Access layer provides connection to endpoints. Access layer switches forward frames to another access switch via distribution layer switches.
A router needs to be configured with IPv6 Stateless Autoconfiguration. What command will help configure the router with IPv6 SLAAC and which one will help verify it?
A. 1) ipv6 stateless autoconfig
2) show interface description
B. 1) interface [inferface_id]
ipv6 autoconfig
2) show ipv6 interface brief
C. 1) interface [interface_id]
ipv6 address autoconfig
2) show ipv6 interface [interface_id]
D. 1) interface [interface_id]
ipv6 stateless autoconfig
2) show ipv6 interface summary
C. 1) interface [interface_id]
ipv6 address autoconfig
2) show ipv6 interface [interface_id]
The interface [interface-id] and ipv6 address autoconfig commands are used to configure a router with IPv6 SLAAC. The show ipv6 interface [interface_id] command is used to verify the configuration use command.
There are two ways a router interface dynamically learns an IPv6 address. Stateful DHCP and Stateless Address Autoconfiguration (SLAAC). If the ipv6 address autoconfig command is configured on a router, the interface first listens to the RA message and then assigns itself a global address.
An administrator needs to provide network connectivity to 50 computers in different subnets. Which device should the administrator select to facilitate data communication between these computers?
A. Router
B. Hub
C. Firewall
D. Switch
A. Router
To facilitate network connectivity between 50 computers in different subnets, the administrator should select a router as a network device. Routers filter networks that are based on layer 3 information such as IP address. By default, routers don’t forward broadcast but are used to break collision domain. The various functions of routers are packet switching, packet filtering, internetwork communication, and path selection.
An administrator wants to add another router to a network using stateless auto-configuration on an interface. What command helps accomplish the task?
A. interface fastethernet 0/0
ipv6 address autoconfig default
B. interface fastethernet 0/0
ipv6 address dhcp
C. interface fastethernet 0/0
autoconfig
ipv6 address default
D. interface fastethernet 0/0
ipv6 unicast-routing
A. interface fastethernet 0/0
ipv6 address autoconfig default
To add a router using stateless auto-configuration on an interface, the administrator needs to use the following command.
interface fastethernet 0/0
ipv6 address autoconfig default
The command is used to enable automatic configuration of IPv6 addresses using stateless auto-configuration on an interface. It discovers prefixes on the link and then adds the EUI-64-based addresses to the interface.
A remote site user is unable to access the Microsoft server deployed at the HQ site. The IP address of the user’s computer is 192.168.170.3 What basic troubleshooting steps does a network engineer need to follow to identify the cause? The network setup is as follows:
Site router interface Ethernet 0 has been assigned the IP address 192.168.170.1.
The remote site user’s IP address is in the range of 192.168.170.2 and 192.168.170.31.
The Microsoft server’s IP address is 192.168.192.2.
A. Ping 192.168.192.2 and check the domain name system settings.
B. Ping 127.0.0.1, ping 192.168.170.3, ping 192.168.170.1, and ping 192.168.192.2.
C. Check the Dynamic Host Configuration Protocol settings.
D. Ping the DNS server IP address. If successful, ping the IP address of the HQ router.
B. Ping 127.0.0.1, ping 192.168.170.3, ping 192.168.170.1, and ping 192.168.192.2.
The network engineer needs to take the following step:
Ping 127.0.0.1 (loopbackIP), 192.168.170.3 (ping NIC), 192.168.170.1 (default gateway), and 192.168.192.2 (HQ server).
The network engineer needs to take four basic troubleshooting steps on the user’s computer to check network connectivity.
1) The network engineer should ping the loopback IP address. It confirms whether the user’s IP stack is initialized. If it fails, TCP/IP on the host needs to be reinstalled.
2) If step one is successful, the engineer needs to ping the local host IP address to confirm that the NIC card is working. If it fails, there is an issue with the NIC card or LAN driver.
3) If step two is successful, the engineer needs to ping the default gateway IP address to confirm connectivity from the computer to the router.
4) If step three is successful, the last step is to ping the Microsoft server to check the connectivity from the router to the server at the HQ location. If the ping response is fine, DNS settings need to be verified.
