Explanation
One possible reason why users are unable to reach the site after the security team updated the web server to require https:// in the URL is that the firewall rules are blocking the traffic to port 443. Port 443 is the default port for HTTPS, which is the protocol that encrypts and secures the web communication. If the firewall rules do not allow inbound traffic to port 443, then users will not be able to access the web server using HTTPS12.
To troubleshoot this issue, the security team should configure inbound firewall rules to allow traffic to port
443. This can be done by using the firewall-cmd command on RHEL 8.2, which is a tool that manages firewalld, the default firewall service on RHEL. The command to add a rule to allow traffic to port 443 is:
firewall-cmd --permanent --add-port=443/tcp
The --permanent option makes the rule persistent across reboots, and the --add-port option specifies the port number and protocol (TCP) to allow. After adding the rule, the security team should reload the firewalld service to apply the changes:
firewall-cmd --reload
The security team can verify that the rule is active by using this command:
firewall-cmd --list-ports
The output should show 443/tcp among the ports that are allowed34.
The other options are not relevant to troubleshooting this issue. Configuring the switch port with the correct VLAN may help with network segmentation or isolation, but it will not affect the HTTPS protocol or port.
Configuring the router to include the subnet of the server may help with network routing or connectivity, but it will not enable HTTPS communication. Configuring the server with a default route may help with network access or reachability, but it will not allow HTTPS traffic.

Jitter is the variation in the delay of packets arriving at a destination. Jitter can cause problems for real-time applications, such as voice and video, that require consistent and smooth delivery of packets. A geographically remote office that connects to the main office via a WAN link may experience high jitter due to factors such as network congestion, routing changes, or link quality. Jitter can be reduced by using quality of service (QoS) mechanisms that prioritize and shape traffic according to its importance and sensitivity. Reference: [CompTIA Network+ Certification Exam Objectives], What is Jitter? | Network Jitter Explained | SolarWinds

The time-to-live (TTL) field is the mechanism for ending loops at Layer 3, which is the network layer of the OSI model. The TTL field is an 8-bit field that indicates the maximum time or number of hops that an IP packet can travel before it is discarded. Every time an IP packet passes through a router, the router decrements the TTL value by one. If the TTL value reaches zero, the router drops the packet and sends an ICMP message back to the source, informing that the packet has expired. This way, the TTL field prevents an IP packet from looping endlessly in a network with routing errors or cycles123.
The other options are not mechanisms for ending loops at Layer 3. The checksum field is a 16-bit field that is used to verify the integrity of the IP header. The checksum field is calculated by adding all the 16-bit words in the header and taking the one's complement of the result. If the checksum field does not match the calculated value, the IP packet is considered corrupted and discarded12. The type field, also known as the type of service (TOS) or differentiated services code point (DSCP) field, is an 8-bit field that is used to specify the quality of service (QoS) or priority of the IP packet. The type field can indicate how the packet should be handled in terms of delay, throughput, reliability, or cost12. The protocol field is an 8-bit field that is used to identify the transport layer protocol that is encapsulated in the IP packet. The protocol field can indicate whether the payload is a TCP segment, a UDP datagram, an ICMP message, or another protocol12.

Explanation
The cause of the connection issue is a routing loop. A routing loop is a situation where a packet is forwarded in circles between routers, never reaching its destination. A routing loop can be caused by misconfigured or inconsistent routing tables, or by routing protocols that do not update their information properly. A routing loop can be detected by using the traceroute command, which shows the path taken by a packet from the source to the destination. The traceroute output in the image shows that the packet is bouncing back and forth between two routers, 10.12.2.1 and 10.12.2.2, indicating a routing loop. References: CompTIA Network+ N10-008 Certification Study Guide, page 181; The Official CompTIA Network+ Student Guide (Exam N10-008), page 7-9.