The most efficient subnet mask for a point-to-point heartbeat connection between two servers using IP addressing is /30. A /30 subnet mask has 255.255.255.252 as its decimal representation and 11111111.11111111.11111111.11111100 as its binary representation. This means that there are only two bits available for the host portion of the IP address, which allows for four possible combinations: 00, 01, 10, and 11. However, the first and the last combinations are reserved for the network address and the broadcast address, respectively. Therefore, only two IP addresses are usable for the point-to-point connection, which is the minimum required for such a link. A /30 subnet mask is also known as a point-to-point prefix because it is commonly used for point-to-point links between routers or servers1.
A /28 subnet mask has 255.255.255.240 as its decimal representation and 11111111.11111111.11111111.11110000 as its binary representation. This means that there are four bits available for the host portion of the IP address, which allows for 16 possible combinations. However, two of them are reserved for the network address and the broadcast address, respectively. Therefore, 14 IP addresses are usable for the subnet, which is more than needed for a point-to-point connection and would result in wasted addresses.
A /29 subnet mask has 255.255.255.248 as its decimal representation and 11111111.11111111.11111111.11111000 as its binary representation. This means that there are three bits available for the host portion of the IP address, which allows for eight possible combinations. However, two of them are reserved for the network address and the broadcast address, respectively. Therefore, six IP addresses are usable for the subnet, which is still more than needed for a point-to-point connection and would result in wasted addresses.
A /32 subnet mask has 255.255.255.255 as its decimal representation and 11111111.11111111.11111111.11111111 as its binary representation. This means that there are no bits available for the host portion of the IP address, which allows for only one possible combination: all ones. Therefore, only one IP address is usable for the subnet, which is not enough for a point-to-point connection and would result in an invalid configuration.
Therefore, a /30 subnet mask is the most efficient choice for a point-to-point heartbeat connection between two servers using IP addressing because it provides exactly two usable IP addresses without wasting any addresses or creating any conflicts1.

Explanation
A tabletop exercise is a type of disaster recovery testing exercise that is primarily used to discuss incident response strategies for critical systems without affecting production data. A tabletop exercise is a discussion-based session where team members meet in an informal, classroom setting to review their roles and responsibilities during an emergency and their responses to a hypothetical scenario. A facilitator guides the participants through the discussion and evaluates the strengths and weaknesses of the preparedness program. A tabletop exercise does not involve any actual deployment of resources or activation of systems12. A backup recovery test (B) is a type of disaster recovery testing exercise that involves restoring data from backup media to verify its integrity and availability. A backup recovery test may affect production data if it is not performed on a separate environment. A live failover is a type of disaster recovery testing exercise that involves switching operations from a primary site to a secondary site in case of a failure or disruption. A live failover may affect production data if it is not performed on a simulated environment. A hot-site visit audit (D) is a type of disaster recovery testing exercise that involves inspecting and evaluating a hot site, which is a backup location that has fully operational equipment and resources to resume business operations in case of a disaster. A hot-site visit audit does not involve any discussion of incident response strategies or simulation of scenarios. References: 1 https://www.ready.gov/testing-exercises 2 https://www.ready.gov/exercises

When a Port LED is Amber the Port is not forwarding. This is possibly due to:
1: The port being disabled by management,
2: an address violation, or Spanning Tree Protocol (STP).
After the port is reconfigured, the port LED can remain amber for up to 30 seconds while STP checks the switch for possible loops.
https://networkengineering.stackexchange.com/questions/14905/why-only-one-amber-light- between-two-switches