CCNA Routing & Switching 200-125: New Questions - Part 1

The given CIDR notation (255.255.255.252) represents a subnet mask that has 30 bits set to 1. In CIDR notation, the number after the forward slash (/) indicates the number of network bits in the subnet mask. Since there are 30 network bits in this subnet mask, the correct answer is 30.

Category 5e and Category 6 cables are capable of supporting 1-Gbps Ethernet. These cable specifications have the necessary bandwidth and performance capabilities to handle the high data transmission rate required for 1-Gbps Ethernet. RG11 and RG-6 cables are typically used for video and television applications, while Category 3 cables are older and have lower bandwidth, making them unsuitable for 1-Gbps Ethernet.

Collisions on the interface can cause a duplex mismatch problem. Duplex mismatch occurs when two connected devices have different duplex settings, such as one device operating in full-duplex mode while the other is in half-duplex mode. This mismatch can lead to collisions on the interface, where both devices try to transmit data at the same time, resulting in data loss and performance issues. Therefore, collisions on the interface can be a symptom of a duplex mismatch problem.

The option "Switch-Cisco!" is an invalid hostname for a switch because it contains an exclamation mark, which is not allowed in a hostname. Hostnames can only consist of letters, numbers, and hyphens, and they cannot start or end with a hyphen. Therefore, "Switch-Cisco!" does not meet the criteria for a valid hostname.

The correct answer is "ssh -v 2 -l admin 10.1.1.1". This command uses the "-v" flag to enable verbose mode, which provides more detailed information about the SSH connection. The "2" after the "-v" flag specifies that SSH version 2 should be used, which is more secure than version 1. The "-l admin" option specifies the username "admin" to log in with, and "10.1.1.1" is the IP address of the server to connect to. This command ensures that a strong and secure SSH connection is established by using SSH version 2 and providing the necessary login credentials.

In the initial TCP SYN message, the sequence number is included. The sequence number is used to keep track of the order of the packets being sent and received. It helps in ensuring that the packets are reassembled correctly at the receiving end. By including the sequence number in the SYN message, the sender can establish a reliable communication channel with the receiver.

Policing is a QoS feature that can drop traffic that exceeds the committed access rate. Policing is used to enforce a specific bandwidth limit on a network interface or traffic flow. It monitors the incoming traffic and checks if it exceeds the allowed rate. If the traffic exceeds the limit, policing can drop or mark the excess packets, ensuring that the network resources are not overwhelmed and maintaining the quality of service for other traffic flows.

Dynamic MAC addresses are automatically aged by the switch. This means that the switch will remove the dynamic MAC addresses from its MAC address table after a certain period of inactivity. Dynamic MAC addresses are learned by the switch when a device sends a frame to the network, and they are aged to ensure that the MAC address table remains up to date and does not contain unnecessary entries.

A point-to-point leased line offers the benefit of simple configuration. This means that setting up the connection between two locations is straightforward and does not require complex network configurations. This simplicity can save time and effort during the installation process.

A firewall is a network security device that monitors and filters incoming and outgoing network traffic based on predetermined security rules. It acts as a barrier between a trusted internal network and an untrusted external network, such as the internet. By using a firewall, you can preserve IP addresses on your network by controlling access to and from specific IP addresses, preventing unauthorized access and preserving the integrity of your network.

To verify that a 128-bit address is live and responding, you can use the "ping ipv6" command. This command specifically checks for the connectivity of IPv6 addresses. By sending an ICMPv6 echo request to the specified address, the command will determine if the address is active and able to respond. This is useful for troubleshooting network connectivity and ensuring that the address is reachable.

The three ports that will be STP designated ports are Switch A - Fa0/1, Switch B - Fa0/0, and Switch B - Fa0/1. This is because in Spanning Tree Protocol (STP), designated ports are selected based on the lowest path cost. Since all the links are operating at the same bandwidth, the path cost will be the same for all the links. Therefore, the designated ports will be chosen based on the lowest interface priority. In this case, Switch A - Fa0/1 has the lowest interface priority, followed by Switch B - Fa0/0 and Switch B - Fa0/1.

MPLS (Multiprotocol Label Switching) is a networking technology that uses a label to separate traffic from multiple customers. It does not rely on IPv4 or IPv6 addresses or MAC addresses for this purpose. Instead, MPLS adds a label to each packet, allowing routers to quickly and efficiently direct traffic based on the label. This allows for improved traffic management, quality of service, and network performance.

BGP (Border Gateway Protocol) requires the AS (Autonomous System) number to be configured on both the local and remote routers in order to establish a connection. The AS number is a unique identifier assigned to each autonomous system on the internet. By configuring the AS numbers on both routers, BGP can establish a connection and exchange routing information between them. Enabling CDP (Cisco Discovery Protocol), IGP (Interior Gateway Protocol), and EGP (Exterior Gateway Protocol) are not necessary for BGP to establish a connection.

The spanning-tree root bridge is elected based on two conditions: the lowest MAC address and the lowest switch priority. The MAC address is a unique identifier assigned to each network device, and the switch with the lowest MAC address will become the root bridge. The switch priority is a value that can be manually configured, and the switch with the lowest priority will also become the root bridge. These two conditions ensure that the root bridge is selected in a deterministic manner based on specific criteria.

The exhibit is not available, so a specific explanation cannot be provided.

When using a MDI (Medium Dependent Interface) connection, a crossover cable is required. This type of cable allows for the direct connection between two similar devices, such as two computers or two switches, without the need for a hub or switch in between. The crossover cable is designed to swap the transmit and receive signals, ensuring proper communication between the devices. This is in contrast to a straight-through cable, which is used to connect different types of devices, such as a computer to a switch. A rollover cable, on the other hand, is used for connecting a computer to the console port of a network device for management purposes.

The requirements for running VTP are that the VTP domain names must be the same and all devices need to have the same VTP version. This ensures that all devices within the VTP domain are synchronized and can exchange VLAN information effectively. Having the same domain name allows devices to recognize each other as part of the same VTP domain, while having the same VTP version ensures compatibility and consistent VLAN configuration across all devices.

If a route is not present in the routing table for a particular destination, the router would drop the packet. This means that the router would discard the packet and not forward it to any other destination. Dropping the packet is the default action taken by the router when it does not have a specific route for a destination.

The multicast MAC address range is 01:00:5E:xx:xx:xx, which means that the first byte starts with 01 and the second byte starts with 00. This range is reserved for multicast addresses. Multicast addresses are used for one-to-many communication, where a single packet is sent to multiple recipients. Therefore, the statements "01:00:5E:xx:xx:xx" and "one to many" are both true for multicast MAC address directions.

The correct answer is that the "AAA new-model" configuration command enables AAA services on the device. AAA stands for Authentication, Authorization, and Accounting, and it is a security framework used to control access to network resources. By enabling AAA services on the device, it allows for the authentication of users, authorization of their access privileges, and accounting of their network usage. This command is typically used in Cisco devices to enable AAA functionality.

The designated ports in STP are the ports that are chosen as the primary path for forwarding traffic in each segment. In this topology, the designated ports will be the ports that have the lowest cost to reach the root bridge. Since the question states that all the links are operating at the same bandwidth, the cost to reach the root bridge will be the same for all ports. Therefore, the designated ports will be Switch A - Fa0/1, Switch B - Fa0/0, and Switch B - Fa0/1.

The extended traceroute command allows the user to send packets from a specified interface or IP address. This means that the user can choose the source of the packets, which can be useful in certain network troubleshooting scenarios. Additionally, the extended traceroute command can also use a specified TTL (Time-to-Live) value. The TTL value determines the maximum number of hops that a packet can take before being discarded, and by specifying this value, the user can control the depth of the traceroute.

UDP (User Datagram Protocol) is a connectionless protocol that does not use a three-way handshake to ensure proper transmission of traffic. Therefore, the statement "It uses a three-way handshake to ensure that traffic is transmitted properly" is false. UDP can transmit data at a rate higher than the path capacity because it does not perform flow control, making it suitable for real-time applications. It can also be used for multicast and broadcast traffic, allowing data to be sent to multiple recipients simultaneously. However, UDP does not guarantee packet delivery, and it does not include protection against duplicate packets.

CDP (Cisco Discovery Protocol) is a proprietary Cisco protocol used to share information about directly connected Cisco devices. It runs on the data link layer, allowing devices to discover and learn about each other on the same network segment. CDP does not operate on the network layer. It uses TLVs (Type, Length, Value) to share device information such as device ID, software version, and IP address. SNMP (Simple Network Management Protocol) is a different protocol used for network management and monitoring, not for sharing device information via CDP. Therefore, the correct statements are: CDP runs on the data link layer only, and CDP uses TLVs to share device information.

Cisco Discovery Protocol (CDP) is a Cisco proprietary protocol used to share device information between Cisco devices. It runs on the data link layer only, providing information about neighboring devices. It does not operate on the network layer. CDP uses Type Length Value (TLV) format to share device information such as device ID, software version, and IP addresses. It is not used to initiate a VTP server and client relationship, nor does it use SNMP to share device information to an external server.

Split-horizon is a technique used in distance vector protocols to prevent routing loops. In distance vector protocols, each router sends its routing table to its neighboring routers. Split-horizon prevents a router from advertising a route back to the same router it received it from. This helps to avoid the scenario where routers continuously exchange routing information in a loop, leading to inefficient routing and network congestion. By not advertising routes back to the same router, split-horizon ensures that routing loops are avoided and the network operates more efficiently.

Priority Queuing (PQ) is the correct answer because it allows voice traffic to be given higher priority over data traffic. This ensures that voice packets are transmitted with minimal delay and jitter, which is crucial for maintaining voice quality. By assigning voice traffic to a separate priority queue, it can be processed and transmitted ahead of data traffic, optimizing the network for voice communication.

The frame check sequence is a field in an Ethernet frame that is used for error detection and ensures the integrity of the data being transmitted. The type field identifies the protocol being used in the frame, such as IPv4 or IPv6. Both of these fields are essential components of an Ethernet frame.

SPAN and RSPAN are two features that can be enabled on a switch to capture and analyze frames that transit an interface. SPAN (Switch Port Analyzer) allows the monitoring of network traffic by copying incoming and outgoing traffic on one or more ports to a designated monitoring port. RSPAN (Remote Switch Port Analyzer) extends this capability to remote switches, allowing the monitoring of traffic on multiple switches across a network. SNMP (Simple Network Management Protocol), NetFlow, and IP SLA are not specifically designed for capturing and analyzing frames, making them incorrect choices.

The given configuration is dropping traffic from PC B when it uses the trunk to communicate with PC A. This means that any data sent from PC B to PC A through the trunk will not reach its destination and will be discarded.

The first statement, "The interfaces configured in the EtherChannel must operate at the same speed and duplex mode," is true because for an EtherChannel to function properly, all interfaces within the channel need to have the same speed and duplex settings. This ensures that there is no mismatch or inconsistency in the transmission of data.

The fourth statement, "The interfaces configured in the EtherChannel must be part of the same VLAN or trunk," is also true because in order to create an EtherChannel, the interfaces must be either in the same VLAN or be trunk ports. This allows for the aggregation of multiple links into a single logical link, providing increased bandwidth and redundancy.

In the context of NTP (Network Time Protocol), the redundancy is represented by the "N+1" option. This means that there are N primary time servers and one backup time server. The backup server is ready to take over the time synchronization duties in case any of the primary servers fail or become unavailable. Having this redundancy ensures that there is always a reliable source of accurate time for the network.

Dual-homed WAN connections are more expensive than single-homed connections because they require additional hardware and redundancy to ensure high availability. Additionally, dual-homed connections require more skill to administer as they involve configuring and managing multiple connections and ensuring proper failover and load balancing.

Setting both sides of the connection to full duplex ensures that both switches are communicating at the same speed and in the same direction, eliminating the possibility of a duplex mismatch. Setting both sides of the connection to auto-negotiate allows the switches to automatically determine the appropriate duplex setting based on their capabilities, avoiding any mismatch errors. Setting both sides of the connection to half duplex may also work, but it limits the communication to one direction at a time, potentially reducing network performance.

MPLS (Multiprotocol Label Switching) can be implemented on both redundant and non-redundant links. This means that MPLS can be used on network connections that have backup or redundant links as well as on connections that do not have redundancy. This flexibility allows for efficient and reliable routing of data packets, ensuring optimal performance and fault tolerance in the network. MPLS is not limited to a specific type of network, such as LAN or WLAN, but can be implemented across various types of networks.

IP SLA ICMP Echo measures the end-to-end response time. This means it measures the time it takes for a packet to travel from the source to the destination and back again. By measuring the end-to-end response time, network administrators can assess the quality and performance of their network connections.

Based on the exhibit, the network configuration shows that RTRO1 is advertising three networks: 10.0.0.0, 172.16.0.0, and 192.168.2.0. These networks will be received by other routers running EIGRP on the network. The other networks mentioned in the options (172.16.4.0, 192.168.0.0, and 10.4.3.0) are not advertised by RTRO1 and therefore will not be received by other routers.

DTP stands for Dynamic Trunking Protocol, which is a Cisco proprietary protocol used to negotiate trunking between switches. It operates at Layer 2 of the OSI model, making the first option "Layer 2 protocol" true. Additionally, DTP is a proprietary protocol developed by Cisco, making the second option "Proprietary protocol" true. Finally, DTP is enabled by default on Cisco switches, making the third option "enabled by default" true.

Syslog logging at the severity level of "emergency" can begin to affect router performance. This is because emergency level logging is the highest severity level, indicating critical system failures or conditions that require immediate attention. When the router is logging at this level, it is likely generating a large volume of logs, which can consume system resources and impact performance. Therefore, it is important to carefully consider the severity level used for syslog logging to balance the need for information with the potential impact on router performance.

The first statement, "Single-mode cable is most appropriate for installations longer than 10 km," is true because single-mode fiber is designed to carry signals over long distances with low signal loss.

The fourth statement, "Multimode cable supports speeds between 100 Mbps and 100 Gbps," is also true because multimode fiber is capable of supporting a range of speeds, from 100 Mbps to 100 Gbps, depending on the specific type of multimode fiber being used.

IP SLA (Internet Protocol Service Level Agreement) is a feature or utility that enables a switch or router to monitor network performance and availability using a responder. It allows network administrators to measure network performance metrics such as delay, jitter, and packet loss. By sending synthetic traffic to a specific destination and analyzing the responses, IP SLA provides valuable insights into network performance and helps in troubleshooting network issues. It is a powerful tool for network monitoring and optimization.

EIGRP (Enhanced Interior Gateway Routing Protocol) is the routing protocol that is used to determine the route learned by the interface mentioned in the question. OSPF (Open Shortest Path First), RIP (Routing Information Protocol), and BGP (Border Gateway Protocol) are also routing protocols, but the correct answer in this case is EIGRP.

In a spanning-tree network, each VLAN must have its own root bridge. This is because the root bridge is elected based on the bridge ID, which consists of a priority value and the MAC address of the switch. By default, the switch with the lowest bridge ID becomes the root bridge for a particular VLAN. Therefore, each VLAN can have a different root bridge based on the bridge ID. This allows for load balancing and redundancy in the network.

When you change the weight and distance parameters on a device with an established BGP neighbor, you need to reset the BGP connections on the device. This is because BGP uses TCP connections to establish and maintain neighbor relationships. When you change the weight and distance parameters, it can affect the BGP decision-making process and the routes exchanged between the devices. By resetting the BGP connections, you ensure that the devices reestablish their neighbor relationships and exchange the updated routes based on the new weight and distance settings.

IPv6 Unique Local Addresses (ULA) are the counterpart of IPv4 private addresses. They are used for local communication within a specific organization or site. They are not routable on the public internet. ULA uses the FC00::/7 prefix, which means that the first 7 bits of the address are fixed. This prefix allows for a large number of unique local addresses to be generated. Therefore, the two true statements about IPv6 Unique Local Addresses are that they are the counterpart of IPv4 private addresses and they use the FC00::/7 prefix.

The types of IPv6 static routes are recursive routes, directly connected routes, and fully specified routes. Recursive routes are used when the next-hop address is not known and the router needs to recursively query other routers to find the next-hop address. Directly connected routes are routes to networks that are directly connected to the router's interfaces. Fully specified routes include both the network address and the next-hop address.

RSTP combines the listening and blocking spanning-tree port states to allow faster convergence. The listening state is a transitional state where the port receives BPDUs and prepares to move to the forwarding state. The blocking state is a state where the port does not forward any traffic but still receives BPDUs to determine the topology. By combining these two states, RSTP can quickly determine the best path and converge the network faster.

CDP (Cisco Discovery Protocol) is a Cisco proprietary protocol that can be used to detect native VLAN mismatch errors. It allows Cisco devices to share information about their capabilities and configurations, including VLAN information. By comparing the VLAN information exchanged through CDP, devices can identify if there is a native VLAN mismatch.

STP (Spanning Tree Protocol) is a standardized protocol used to prevent loops in a network. It can also detect native VLAN mismatch errors by comparing the VLAN information in the BPDU (Bridge Protocol Data Unit) messages exchanged between switches. If the VLAN information in the BPDU does not match, it indicates a native VLAN mismatch.

Anycast addresses in IPv6 receive packets on the closest interface that is discovered by the routing protocol. This means that when multiple interfaces have the same anycast address assigned, the routing protocol will direct incoming packets to the interface that is geographically closest to the sender. Anycast addresses are allocated from the IPv6 unicast address space, not from the broadcast address space.