Bridging Elements and Terminology JN0-364 Practice Questions (Page 5)

Questions 21–25

1. 21application · easy

   A switch receives a frame with a destination MAC address that is not present in its forwarding database. The frame is a unicast frame. What will the switch do?

   • ADrop the frame because the destination is unknown.
   • BSend the frame only to the default gateway.
   • CFlood the frame out of all ports in the same bridge domain, except the port it was received on.
   • DSend the frame back to the source port to request a retransmission.
   Reveal Solution Discussion Select an answer first
2. 22application · medium

   A company has two VLANs, 10 and 20, on the same switch. Hosts in VLAN 10 need to communicate with hosts in VLAN 20. The switch is a pure Layer 2 switch. What is required to enable this communication?

   • AA Layer 2 trunk port connecting the two VLANs.
   • BA Layer 2 switch cannot support inter-VLAN communication under any circumstances.
   • CA single bridge domain that includes both VLANs.
   • DA router with subinterfaces configured for each VLAN, connected to the switch via a trunk port.
   Reveal Solution Discussion Select an answer first
4. 23foundation · easy

   What is a common mitigation for broadcast storms in a Layer 2 network?

   • AImplementing Spanning Tree Protocol (STP) to eliminate loops.
   • BDisabling MAC address learning.
   • CIncreasing the MTU on all interfaces.
   • DUsing a router instead of a switch.
   Reveal Solution Discussion Select an answer first
5. 24foundation · easy

   Why do switches implement MAC address aging?

   • ATo prevent MAC address spoofing attacks.
   • BTo reduce the size of the forwarding table by permanently removing all entries after a set time.
   • CTo remove stale entries and keep the forwarding database current as devices move or go offline.
   • DTo increase the speed of MAC address learning.
   Reveal Solution Discussion Select an answer first
6. 25foundation · medium

   A Junos switch receives a frame on an access port. The switch looks up the destination MAC address in its Layer 2 forwarding table and finds a matching entry. What action does the switch take based on that lookup?

   • AIt floods the frame out all ports in the same VLAN except the ingress port.
   • BIt drops the frame because the destination MAC address is already known.
   • CIt forwards the frame only out the port associated with the destination MAC address in the forwarding table.
   • DIt sends the frame to the Routing Engine for a Layer 3 forwarding decision.
   Reveal Solution Discussion Select an answer first