Explanation
It does this by using a two-level hierarchy of switches, where the spine switches connect to the leaf switches, which in turn connect to the end hosts. This reduces the number of hops a packet must take from one host to another, thus reducing latency. According to the CompTIA Network+ N10-008 Exam Guide, the Spine and Leaf topology is a modern architecture that is used to reduce latency in large networks.

* The firewall logs are the best source of information to determine whether an internal server was accessed by hosts on the internet, as they record all the traffic that passes through the firewall, including the source and destination IP addresses, ports, protocols, and actions taken by the firewall rules.
* The server's syslog is a file that records events and messages related to the server's operation, such as system errors, warnings, or notifications. It may not contain information about the network traffic to and from the server, especially if the server was shut down during the investigation.
* The NetFlow statistics are a network protocol that collects and analyzes data about the network traffic flows, such as the volume, type, and direction of the traffic. It can provide useful information about the network performance and utilization, but it may not show the details of the individual packets or the firewall actions.
* The audit logs on the core switch are a record of the configuration changes and commands executed on the switch, such as adding, deleting, or modifying VLANs, ports, or routing protocols. They can help troubleshoot or verify the switch's operation, but they may not show the network traffic to and from the server.
References:
* CompTIA Network+ N10-008 Study Guide, Chapter 7: Network Security, Section 7.2: Network
* Security Devices and Technologies, p. 372-373
* Professor Messer's CompTIA N10-008 Network+ Course Notes, Section 5.1: Network Monitoring Tools, p. 51
* Professor Messer's CompTIA N10-008 Network+ Training Course, Video 5.1: Network Monitoring Tools, 12:28-14:02

A CIDR notation of /26 refers to the number of bits used for the network prefix. In this case, the network prefix is 26 bits long, which leaves 6 bits for the host addresses. In a CIDR notation /26, the first 26 bits of the IP address represent the network and the last 6 bits represent the host addresses.
In this case, the IP address range is 80.87.78.0 - 80.87.78.63 and the network address is
80.87.78.0, so the first usable IP address for devices is 80.87.78.1 and the last usable IP address is 80.87.78.62.

Explanation
The transport layer is the fourth layer of the OSI model, and it is responsible for end-to-end delivery of data over a network. It uses standard protocols such as TCP, UDP, and DCCP to enhance its functionalities. One of the main functions of the transport layer is to ensure that messages are transmitted to their destinations reliably and in the correct order. It also prevents data duplication by using sequence numbers, acknowledgments, and retransmission mechanisms