Exam 200-301 topic 1 question 949 discussion

C. Type of Service For sure

This is what ChatGPT gives as an answer.

С. While DSCP values are written into the ToS field, DSCP itself is not a standalone IP header field—it’s part of the ToS byte.

DSCP has replaced the traditional ToS.

The correct answer is: **D. DSCP** When Quality of Service (QoS) marking is enabled on a Cisco device, it typically modifies the **DSCP (Differentiated Services Code Point)** field in the IP header. This field is used for defining the level of service (e.g., priority) that should be applied to the packet as it traverses the network.

When QoS (Quality of Service) marking is enabled on a Cisco device, the DSCP (Differentiated Services Code Point) field in the IP header is typically modified. DSCP is part of the Type of Service (ToS) byte in the IP header and is used to classify and prioritize traffic.

When QoS marking is enabled, a Cisco device modifies the Type of Service (ToS) field in the IP header. The DSCP value, used for prioritizing traffic, is part of this field. A. ECN is for congestion control. B. Header Checksum is for error-checking. D. DSCP is part of the ToS field. So, the Type of Service (ToS) field is the one changed for QoS marking.

“Which IP header Field” DSCP is not a field in an IP header I think? So I would go with C.

D. DSCP (Differentiated Services Code Point) Here's why: DSCP: This is the most significant portion (3 bits) within the Type of Service (ToS) field of the IP header. Cisco devices primarily rely on manipulating the DSCP bits to set specific markings for traffic prioritization in QoS configurations. Type of Service (ToS): This is the broader 8-bit field in the IP header that encompasses the DSCP bits and 5 unused bits. While ToS itself is the modified field, the DSCP portion carries the specific QoS marking information.

DSCP Is the answer

D for DSCP

DSCP -> by having generally agreed upon standard marking sfor different kinds of traffic, QoS design & implementation is simplified, QoS works better between ISPs and enterprises, among other benefits

C is correct TOS

from chatgtp, In traditional IP headers, there is a field called the "Type of Service" (ToS) field. However, in modern implementations, the ToS field has been deprecated and replaced by the Differentiated Services Code Point (DSCP) field. The ToS field was originally intended to specify the quality of service requested for a packet. It had several subfields, including precedence and delay. However, its functionality was later refined and enhanced, leading to the development of the DSCP field. DSCP provides a more granular and flexible mechanism for specifying the treatment of packets within a network. It allows for a wider range of service levels and prioritization schemes. Therefore, when discussing QoS marking in modern networks, it's more common to refer to the DSCP field rather than the deprecated ToS field. So, in the context of QoS marking enabled by Cisco devices, it's more accurate to say that the Differentiated Services Code Point (DSCP) field is modified or changed, rather than the Type of Service (ToS) field.

c is the correct answer 100%

I have no idea what is this about, but based on the comments, answer should be D.

The field is called ToS, thus C