Dell Networking Foundations Free Sample Questions

For a distance of 150 meters at 10 Gbps, multi-mode fiber is the correct choice. 10GBASE-SR transceivers using OM3 multi-mode fiber can support distances up to 300 meters. Cat6a copper is limited to 100 meters. Single-mode fiber is capable of much longer distances but is typically more expensive and unnecessary for 150 meters. DAC cables are for very short distances, usually within a single rack.

For a device to communicate with other devices outside of its own subnet, it needs a default gateway. The default gateway is the IP address of the router interface that the switch will send all traffic destined for remote networks to. Without it, the switch does not know how to reply to the ping from a different subnet.

MAC address flapping is a classic symptom of a Layer 2 switching loop. This occurs when there are redundant paths between switches and Spanning Tree Protocol (STP) is disabled or misconfigured. The switches continuously update their MAC address tables, associating the same MAC address with different ports as broadcast frames loop endlessly through the network.

The statement is false. LLDP (Link Layer Discovery Protocol) is a vendor-neutral protocol defined by the IEEE 802.1AB standard. Cisco's proprietary neighbor discovery protocol is CDP (Cisco Discovery Protocol). Dell PowerSwitch devices use LLDP for interoperability.

To carry traffic for multiple VLANs between switches, the connecting ports must be configured in trunk mode. Trunk ports use IEEE 802.1Q tagging to identify which VLAN each frame belongs to. Access mode ports can only belong to a single VLAN and transmit untagged traffic.

In STP, the switch with the lowest bridge priority becomes the root bridge. The default priority is 32768. To make Core-1 the primary root, its priority must be set to a value lower than all other switches. Setting Core-2's priority to the next lowest value ensures it will become the root bridge if Core-1 fails. Setting Core-1 to 4096 and Core-2 to 8192 accomplishes this, as both values are lower than the default and 4096 is lower than 8192.

Jumbo frames increase the Ethernet frame size from the standard 1500 bytes to around 9000 bytes. This means that for the same amount of data, fewer frames (and thus fewer headers) need to be processed. This reduction in frame processing leads to lower CPU utilization on both the sending server and the receiving storage array, improving overall throughput for large block storage traffic like iSCSI.

VLANs create separate Layer 2 broadcast domains. By design, devices in different VLANs cannot communicate directly. To enable communication, a Layer 3 device (like a router or a Layer 3 switch) is needed to route traffic between the different VLANs/subnets. This process is called inter-VLAN routing.

RSTP (IEEE 802.1w) simplifies the STP port states for faster convergence. It combines the original STP states of Disabled, Blocking, and Listening into a single 'Discarding' state. In the Discarding state, the port does not forward frames or learn MAC addresses.