Cisco Cisco Certified Support Technician Networking Exam 100-150 Exam Dumps: Updated Questions & Answers (October 2025)

Out-of-band management

When a Cisco switch is not accessible from the network, the recommended out-of-band method to access its running configuration is through the console port. Out-of-band management involves accessing the network device through a dedicated management channel that is not part of the data network. The console port provides direct access to the switch’s Command Line Interface (CLI) without using the network, which is essential when the switch cannot be accessed remotely via the network12.

References :=

Out-of-band (OOB) network interface configuration guidelines

Out of band management configuration

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Firewall: A firewall is a network security device that monitors and controls incoming and outgoing network traffic based on predetermined security rules. It permits or denies traffic based on IP addresses, port numbers, or applications.

Access Point: This is a device that allows wireless devices to connect to a wired network using Wi-Fi. It does not perform traffic filtering based on IP, port, or application.

VPN Gateway: This device allows for secure connections between networks over the internet, but it is not primarily used for traffic filtering based on IP, port, or application.

Intrusion Detection System (IDS): This device monitors network traffic for suspicious activity and policy violations, but it does not actively permit or deny traffic.

References:

Understanding Firewalls: Firewall Basics

The tracert command output shows the path taken to reach the destination IP address, 192.168.1.10. The command output indicates:

•Hops 1 and 2 are successfully reached.

•Hop 3 times out, meaning the router at hop 3 did not respond to the tracert request. However, this does not necessarily indicate a problem with forwarding packets, as some routers may be configured to block or not respond to ICMP requests.

•Hops 4 and 5 are successfully reached, with hop 5 being the destination IP 192.168.1.10, indicating that the server is reachable.

Thus, the correct answer is C. The server with the address 192.168.1.10 is reachable over the network.

References :=

•Cisco Traceroute Command

•Understanding Traceroute

The tracert command output indicates that the server with the address 192.168.1.10 is reachable over the network. The asterisk (*) at hop 3 suggests that the probe sent to that hop did not return a response, which could be due to a variety of reasons such as a firewall blocking ICMP packets or the router at that hop being configured not to respond to ICMP requests. However, since the subsequent hops (4 and 5) are showing response times, it means that the packets are indeed getting through and the server is reachable12.

References :=

•How to Use Traceroute Command to Read Its Results

•How to Use the Tracert Command in Windows

To list the IPv4 addresses associated with the host name www.companypro.net, you should use the following command:

nslookup www.companypro.net

This command will query the DNS servers to find the IP address associated with the hostname provided. If you want to ensure that it returns the IPv4 address, you can specify the -type=A option, which stands for Address records that hold IPv4 addresses1. However, the nslookup command by default should return the IPv4 address if available.

To list the IPv4 addresses associated with the host name www.companypro.net , you should use the nslookup command.

Command: nslookup

Target: www.companypro.net

So, the completed command is:

nslookup www.companypro.net

nslookup: This command is used to query the Domain Name System (DNS) to obtain domain name or IP address mapping or for any other specific DNS record.

www.companypro.net : This is the domain name you want to query to obtain its associated IP addresses.

References:

Using nslookup: nslookup Command Guide

The private IP address ranges that are set aside specifically for use within private networks and not routable on the internet are as follows:

Class A: 10.0.0.0 to 10.255.255.255

Class B: 172.16.0.0 to 172.31.255.255

Class C: 192.168.0.0 to 192.168.255.255

These ranges are defined by the Internet Assigned Numbers Authority (IANA) and are used for local communications within a private network123.

Given the options: A. 172.16.0.0 to 172.31.255.255 falls within the Class B private range. B. 192.16.0.0 to 192.16.255.255 is not a recognized private IP range. C. 11.0.0.0 to 11.255.255.255 is not a recognized private IP range. D. 192.168.0.0 to 192.168.255.255 falls within the Class C private range.

Therefore, the correct selections that the company should use for their private networks are A and D.

References :=

Reserved IP addresses on Wikipedia

Private IP Addresses in Networking - GeeksforGeeks

Understanding Private IP Ranges, Uses, Benefits, and Warnings

IPv6 addresses can be compressed by removing leading zeros and replacing consecutive groups of zeros with a double colon (::). Here’s how to compress the address 2001:0db8:0000:0016:0000:001b:2000:0056:

Remove leading zeros from each segment:

2001:db8:0000:0016:0000:001b:2000:0056 becomes 2001:db8:0:16:0:1b:2000:56

Replace the longest sequence of consecutive zeros with a double colon (::). In this case, the two consecutive zeros between the 16 and 1b:

2001:db8:0:16::1b:2000:56

Thus, the most compressed valid format of the IPv6 address is 2001:db8:0:16::1b:2000:56.

References :=

Cisco Learning Network

IPv6 Addressing (Cisco)

The correct matching of the protocols to their examples is as follows:

DHCP: Assign the reserved IP address 10.10.10.200 to a web server at your company.

DNS: Perform a query to translate companypro.net to an IP address.

ICMP: Perform a ping to ensure that a server is responding to network connections.

Here’s how each protocol corresponds to its example:

DHCP (Dynamic Host Configuration Protocol) is used to assign IP addresses to devices on a network. In this case, DHCP would be used to assign the reserved IP address 10.10.10.200 to a web server.

DNS (Domain Name System) is used to translate domain names into IP addresses. Therefore, to translate companypro.net to an IP address, DNS would be utilized.

ICMP (Internet Control Message Protocol) is used for sending error messages and operational information indicating success or failure when communicating with another IP address. An example of this is using the ping command to check if a server is responding to network connections.

These protocols are essential for the smooth operation of networks and the internet.

Perform a query to translate companypro.net to an IP address.

DNS (Domain Name System): DNS is used to resolve domain names to IP addresses.

Assign the reserved IP address 10.10.10.200 to a web server at your company.

DHCP (Dynamic Host Configuration Protocol): DHCP is used to assign IP addresses to devices on a network.

Perform a ping to ensure that a server is responding to network connections.

ICMP (Internet Control Message Protocol): ICMP is used by network devices to send error messages and operational information, and it is the protocol used by the ping command.

DNS (Domain Name System): DNS translates human-friendly domain names like "companypro.net" into IP addresses that computers use to identify each other on the network.

DHCP (Dynamic Host Configuration Protocol): DHCP automatically assigns IP addresses to devices on a network, ensuring that no two devices have the same IP address.

ICMP (Internet Control Message Protocol): ICMP is used for diagnostic or control purposes, and the ping command uses ICMP to test the reachability of a host on an IP network.

References:

DNS Basics: What is DNS?

DHCP Overview: What is DHCP?

ICMP and Ping: Understanding ICMP

•192.168.200.0/24 Network: This subnet includes all addresses from 192.168.200.0 to 192.168.200.255. The /24 indicates a subnet mask of 255.255.255.0, which allows for 256 addresses.

•192.168.199.13: This address is in the 192.168.199.0/24 subnet, not the 192.168.200.0/24 subnet.

•192.168.200.13: This address is within the 192.168.200.0/24 subnet.

•192.168.201.13: This address is in the 192.168.201.0/24 subnet, not the 192.168.200.0/24 subnet.

•192.168.1.13: This address is in the 192.168.1.0/24 subnet, not the 192.168.200.0/24 subnet.

References:

•Subnetting Guide: Subnetting Basics

SFTP, or Secure File Transfer Protocol, is a protocol that allows for secure file transfer capabilities between networked hosts. It is a secure extension of the File Transfer Protocol (FTP). SFTP encrypts both commands and data, preventing passwords and sensitive information from being transmitted openly over the network. It is typically used for secure file transfers over the internet and is built on the Secure Shell (SSH) protocol1.

References :=

•What Is SFTP? (Secure File Transfer Protocol)

•How to Use SFTP to Safely Transfer Files: A Step-by-Step Guide

•Secure File Transfers: Best Practices, Protocols And Tools

The Secure File Transfer Protocol (SFTP) is a secure version of the File Transfer Protocol (FTP) that uses SSH (Secure Shell) to encrypt all commands and data. This ensures that sensitive information, such as usernames, passwords, and files being transferred, are securely transmitted over the network.

•ICMP (Internet Control Message Protocol) is used for network diagnostics and is not designed for file transfer.

•NTP (Network Time Protocol) is used to synchronize clocks between computer systems and is not related to file transfer.

•HTTP (HyperText Transfer Protocol) is used for transmitting web pages over the internet and does not inherently provide secure file transfer capabilities.

Thus, the correct protocol that allows secure uploading of files to another computer on the internet is SFTP.

References :=

•Cisco Learning Network

•SFTP Overview (Cisco)

The header of a UDP (User Datagram Protocol) segment includes port numbers. Specifically, it contains the source port number and the destination port number, which are used to identify the sending and receiving applications. UDP headers do not include IP addresses or MAC addresses, as those are part of the IP and Ethernet frame headers, respectively. Additionally, UDP does not use sequence numbers, which are a feature of TCP (Transmission Control Protocol) for ensuring reliable delivery of data segments1.

References :=

Segmentation Explained with TCP and UDP Header

User Datagram Protocol (UDP) - GeeksforGeeks

Which three fields are used in a UDP segment header

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UDP Header: The header of a UDP segment includes the following key fields:

Source Port: The port number of the sending application.

Destination Port: The port number of the receiving application.

Length: The length of the UDP header and data.

Checksum: Used for error-checking the header and data.

IP Addresses: These are included in the IP header, not the UDP header.

Sequence Numbers: These are part of the TCP header, not UDP.

MAC Addresses: These are part of the Ethernet frame header and are not included in the UDP header.

References:

RFC 768 - User Datagram Protocol: RFC 768

Cisco Guide on UDP: Cisco UDP Guide