Cisco Enterprise Network Core Technologies (ENCOR) Practice Exam

WRED, or Weighted Random Early Detection, is a congestion avoidance mechanism used in networking to manage traffic and prevent congestion within a network. The technology relies on two specific methods for packet marking: Differentiated Services Code Point (DSCP) and IP precedence. Both DSCP and IP precedence are used to classify and prioritize packets based on their importance or type of service. The selection of packets for dropping in WRED is based primarily on these markings. When the network experiences congestion, WRED evaluates the packet's DSCP value. If a packet has a lower priority (indicated by a lower DSCP value), it is more likely to be dropped compared to higher-priority packets. This intelligent dropping of packets helps in maintaining the quality of service for essential applications by ensuring that more critical traffic is less likely to be affected during peak usage times. Utilizing these traffic classification methods allows WRED to effectively manage network resources by dynamically adjusting which packets are transmitted and which are discarded when the network is congested. Thus, the reliance on DSCP and IP precedence in managing packet drops makes it the correct choice for this question.