While viewing packet capture data, you notice that an IP is sending and receiving traffic for multiple devices by modifying the IP header. Which of the following makes this behavior possible?

The behavior of an IP address sending and receiving traffic for multiple devices by modifying the IP header is primarily facilitated by Network Address Translation (NAT). NAT allows a single public IP address to be shared by multiple devices on a local network. When a device communicates with the outside network, NAT modifies the IP header of the outgoing packets, replacing the source IP address with the public one.

When the responses come back, NAT uses a translation table to keep track of which internal device made the original request and maps the incoming response back to the correct private IP address. This is crucial in conserving IP addresses and providing a level of security since internal IPs are not exposed directly to the outside world.

The other options, while related to networking, operate differently. Tors (Transparent Optical Relay) is primarily involved in layer 2 connectivity and does not modify headers for address reuse. Encapsulation refers to the process of wrapping data with protocol information at each layer of the OSI model, which does not directly relate to the reuse of IP addresses. Tunneling involves encapsulating packets within other packets to support protocol communication over networks but doesn’t inherently involve modifying the IP headers for multiple devices sharing the same public address like NAT does.