QPPB is an acronym for QoS Policy Propogation via BGP. QPPB allows which of these marking behaviors?

A.
The assigning of only a BGP specific community attribute based on the ingress packet DSCP marking.

B.
The assigning of only a BGP specific attribute based on the IP precedence and DSCP of ingress packet.

C.
QPPB provides no marking or classification behaviors.

D.
The use of NBAR to associate an IP Precedence to a packet.

Explanation:
The Quality of Service (QoS) policy propagation via Border Gateway Protocol (BGP) feature allows you to classify packets based on access lists, BGP community lists, and BGP autonomous system (AS) paths. The supported classification policies include Internet Protocol (IP) precedence setting and the ability to tag the packet with a QoS class identifier internal to the router. After a packet has been classified, you can use other QoS features such as Committed Access Rate (CAR) and Weighted Random Early Detection (WRED) to specify and enforce business policies to fit your business model.

The QoS policy propagation via BGP feature was introduced in Cisco IOS Release 11.1(17)CC. With Release 11.1(20)CC, the QoS policy propagation via BGP feature has the following enhancements:

QoS group IDYou can set an internal QoS group ID that can be used later to perform rate-limiting or weighted fair queuing based on the Qos group ID. In the previous release you could only set up to eight IP precedence level to classify packets. By setting the QoS group ID in addition to the IP precedence, you can now have more than eight classes on which to perform rate-limiting or weighted fair queuing.

Source and destination address lookupYou can specify whether the IP precedence level or QoS group ID used is obtained from the source (input) address or destination (output) address entry in the route table. In the previous release you could only use the destination address. You can now specifying the input or output address.

Benefits

BGP policy propagation provides the following benefits:

Allows you to classify packets using access lists, community lists, and AS paths.

Leverages BGP to distribute QoS policy to remote routers in your network.

Allows ingress routers to prioritize incoming and outgoing traffic.

Allows you to classify packets based on IP precedence or QoS group ID.

List of Terms

Autonomous system (AS) pathA collection of networks under a common administration sharing a common routing strategy. BGP carries the AS path in its routing updates. You can filter routing updates by specifying an access list on both incoming and outbound updates based on the BGP AS path.

Border Gateway Protocol (BGP)Interdomain routing protocol that replaces EGP. BGP exchanges reachability information with other BGP systems. It is defined by RFC 1163.

Cisco Express Forwarding (CEF)CEF is an advanced Layer 3 IP switching technology. CEF optimizes network performance and scalability for networks with large and dynamic traffic patterns, such as the Internet, on networks characterized by intensive Web-based applications, or interactive sessions. Although you can use CEF in any part of a network, it is designed for high-performance, highly resilient Layer 3 IP backbone switching.
Committed Access Rate (CAR)CAR limits the input or output transmission rate on an interface or subinterface based on a flexible set of criteria. In addition, CAR classifies packets by setting the IP precedence. CAR can be used to rate-limit traffic based on packet characteristics such access list, incoming interface, or IP precedence. CAR provides configurable actions, such as transmit, drop, or set precedence, when traffic conforms to or exceeds the rate limit.

Community listA community is a group of destinations that share some common attribute. You use community lists to create groups of communities to use in a match clause of a route map. Just like an access list, a series of community lists can be created.

Internet Protocol (IP) precedenceBits within the ToS (type of service) field of the IP header that can be used to classify packets.

QoS group IDUser-specified number that is assigned to a packet when that packet matches user-specified criteria. The packet can then be classified based on that number.

Weighted Random Early Detection (WRED)Drops packets selectively based on IP precedence. Packets with a higher IP precedence are less likely to be dropped than packets with a lower precedence. Thus, higher priority traffic is delivered with a higher probability than lower priority traffic. WRED is useful on any output interface where you expect to have congestion. However, WRED is usually used in the core routers of a network, rather than the edge. Edge routers assign IP precedences to packets as they enter the network. WRED uses these precedences to determine how it treats different types of traffic