NAT (Network Address Translation)

Correct Answer: Update NAT rules

The most likely solution to this problem would be to 'Update NAT rules'. Network Address Translation (NAT) is a process through which IP addresses are mapped from one realm to another, in an attempt to provide transparent routing to hosts. When an ISP (Internet Service Provider) is changed, the NAT rules previously in place may not correspond correctly with the new ISP. Therefore, updating the NAT rules would ensure that all outbound traffic is directed properly, allowing users to reach the correct websites. Switching to a different NAT type would not necessarily solve this issue if the current NAT rules are incorrect. Removing all NAT rules would not be recommended as it might leave the network open to security risks and other connectivity issues. Disabling NAT is generally ill-advised as this could lead to a failure in translating network addresses and problems in data routing.

Correct Answer: Static NAT

Static NAT (Network Address Translation) is used to map a single private IP address to a single public IP address. This is useful for hosting services such as a web server within a private network, making it accessible from the internet. Through Static NAT, the web server will consistently be accessible via a predetermined IP address and port on the router's public interface, which allows external users to find and access the server. Dynamic NAT, on the other hand, would not ensure a predetermined IP address and port, as it dynamically assigns an available public IP address to a device from a pool of addresses. PAT (Port Address Translation), also known as NAT Overload, allows multiple devices on a local network to be mapped to a single public IP address but with different ports. While this works for outgoing connections, it is not reliable for incoming connections to a specific service like a web server that requires consistent accessibility. Overloading NAT is another term for PAT, which is not suitable for the given use case because it doesn't provide a consistent public IP address and port necessary for a web server that should be accessible at all times.

Correct Answer: Static NAT

Static NAT is the best method for a small business with limited public IP addresses that need to connect devices requiring access from the public network. Static NAT, or Network Address Translation, allows a device within a private network to have a dedicated public IP address. This makes it possible for devices from the public network to initiate contact, which is necessary for servers and other types of equipment. Dynamic NAT, on the other hand, assigns public IP addresses from a pool to devices on the private network on a first-come, first-served basis. It is less efficient for situations where specific devices need consistent, direct access. PAT (Port Address Translation) doesn’t provide unique public IP addresses to each internal device; instead, it uses different ports of one IP address to distinguish between the internal devices. Similarly, SNAT (Source NAT) primarily alternates the sources on outgoing packets, not ideal for devices that require public network access.