Which IP header field is changed by a Cisco device when QoS marking is enabled?
Which IP header field is changed by a Cisco device when QoS marking is enabled?
When Quality of Service (QoS) marking is enabled on a Cisco device, the IP header field that is typically changed is the Differentiated Services Code Point (DSCP) field. The DSCP is part of the IP header and is used to indicate the level of service or priority for the packet, which allows the device to prioritize certain types of network traffic over others based on the specified DSCP values.
C. Type of Service For sure
yea, ToS is part of the IP header, and DSCP is one of the fields inside of the ToS(Type of Service)
DSCP is part of ToS
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
"Traffic marking is often used to set the IP precedence or IP DSCP values". "The QoS Packet Marking feature allows you to mark packets by setting the IP precedence bit or the IP differentiated services code point (DSCP) in the Type of Service (ToS) byte...". Type of Service is more correct here, it is also more explicitly an "IP Header field" as defined by RFC 791. See: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/qos_classn/configuration/xe-16/qos-classn-xe-16-book/qos-classn-mrkg-ntwk-trfc-xe.html And: https://datatracker.ietf.org/doc/html/rfc791#page-12
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.
so i think DSCP is the answer which is D
When Quality of Service (QoS) marking is enabled on a Cisco device, the IP header field that is typically changed is the Differentiated Services Code Point (DSCP), which is part of the Type of Service (ToS) field. Therefore, the correct answer is: D. DSCP
D. DSCP When Quality of Service (QoS) marking is enabled on a Cisco device, the IP header field that is typically changed is the Differentiated Services Code Point (DSCP) within the IP header. The DSCP is part of the IP header's TOS (Type of Service) field, and it is used to indicate the desired level of service or priority for a packet.
When QoS (Quality of Service) marking is enabled on a Cisco device, the IP header field that is typically changed is the Differentiated Services Code Point (DSCP). Therefore, the correct answer is: D. DSCP (Differentiated Services Code Point) User sure? ChatGPT I appreciate the double-check. I want to clarify that when QoS marking is enabled on a Cisco device, it is specifically the DSCP (Differentiated Services Code Point) field within the IP header that is modified to implement QoS policies. This allows network devices to prioritize and manage traffic based on the specified DSCP values. So, to reiterate: The correct answer is D. DSCP.
D. DSCP By enabling QoS marking, a Cisco device can prioritize certain types of network traffic over others based on the settings in the DSCP field. This allows for more effective management of network traffic and helps ensure that important data, such as voice or video data, is given priority over less time-sensitive data.
DSCP is the correct answer, it's now defined as a field in the IP header, and ToS is not anymore according to RFC 2474: https://datatracker.ietf.org/doc/html/rfc2474#section-3 Differentiated Services Field Definition A replacement header field, called the DS field, is defined, which is intended to supersede the existing definitions of the IPv4 TOS octet [RFC791] and the IPv6 Traffic Class octet [IPv6]. The DS field structure is presented below: 0 1 2 3 4 5 6 7 +---+---+---+---+---+---+---+---+ | DSCP | CU | +---+---+---+---+---+---+---+---+ DSCP: differentiated services codepoint CU: currently unused