Which of the following fields contained in the IP/TCP/UDP headers can be used to make a routing decision when using policy-based routing? (Choose three)

Policy-based routing commonly uses the source IP address to identify specific hosts or subnets from which traffic originates, allowing for different routing paths based on the source.

TCP flags (e.g., SYN, ACK, FIN) indicate the state or control information of a TCP connection but are typically not used as criteria for making policy-based routing decisions.

Source and destination TCP/UDP ports are crucial for PBR to identify specific applications or services (e.g., HTTP, DNS) and route their traffic differently.

The Type of Service (ToS) field (or its modern equivalent, DSCP) in the IP header is used to categorize traffic and can be leveraged by PBR to apply specific routing paths or quality of service treatments to different classes of traffic.

The Checksum field is used for error detection in headers and data; it is not a parameter used to make routing decisions in policy-based routing.