CoS Processing and Header Fields JN0-664 Practice Questions (Page 1)

Questions 1–5

1. 1foundation · easy

   Which header field is used by BA classification for packets arriving on an MPLS-enabled interface?

   • A802.1p bits
   • BEXP bits
   • CDSCP bits
   • DIP precedence bits
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2. 2foundation · easy

   In Junos CoS, what is the relationship between forwarding classes and queues?

   • AQueues are assigned to interfaces, and forwarding classes are ignored.
   • BForwarding classes are used only for policing, not for queueing.
   • CEach queue can contain packets from multiple forwarding classes, but only one queue is active at a time.
   • DEach forwarding class is mapped to a specific output queue.
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4. 3foundation · easy

   Which statement about the fixed classifier in Junos CoS is correct?

   • AIt is used for all packets that do not match a BA or MF classifier.
   • BIt is configurable to map any header field to any forwarding class.
   • CIt assigns a loss priority based on the EXP bits.
   • DIt maps packets to forwarding classes based on the DSCP value.
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5. 4application · medium

   A service provider needs to classify traffic based on source IP address, destination port, and protocol type. The traffic will be mapped to different forwarding classes to provide differentiated service levels. Which classification method should the engineer use?

   • AFixed classifier based on the incoming interface.
   • BBehavior aggregate (BA) classification using DSCP bits.
   • CBehavior aggregate (BA) classification using EXP bits.
   • DMultifield (MF) classification using a firewall filter.
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6. 5application · medium

   A network engineer is configuring CoS on a router that receives traffic from a customer network. The customer marks traffic with DSCP EF for voice and DSCP AF41 for data. The engineer wants to map voice traffic to the expedited-forwarding forwarding class and data traffic to the assured-forwarding forwarding class. Which configuration should be used?

   • AApply a DSCP-based BA classifier that maps DSCP EF to expedited-forwarding and DSCP AF41 to assured-forwarding.
   • BApply a fixed classifier that maps DSCP EF to expedited-forwarding and DSCP AF41 to assured-forwarding.
   • CApply an EXP-based BA classifier that maps DSCP EF to expedited-forwarding and DSCP AF41 to assured-forwarding.
   • DApply a multifield classifier that matches the DSCP field and assigns forwarding classes.
   Reveal Solution Discussion Select an answer first