CompTIA Network+ N10-009 Syllabus Exam Questions Answers

Introduction to Subinterfaces:

Subinterfaces are logical interfaces created on a single physical interface. They are used to enable a router to support multiple networks on a single physical interface.

Use Case for Subinterfaces:

Subinterfaces are commonly used in scenarios where VLANs are implemented. A router with a single physical LAN port can be configured with multiple subinterfaces, each associated with a different VLAN.

This setup allows the router to route traffic between different VLANs.

Example Configuration:

Consider a router with a single physical interface GigabitEthernet0/0 and two VLANs, 10 and 20.

interface GigabitEthernet0/0.10

encapsulation dot1Q 10

ip address 192.168.10.1 255.255.255.0

!

interface GigabitEthernet0/0.20

encapsulation dot1Q 20

ip address 192.168.20.1 255.255.255.0

The encapsulation dot1Q command specifies the VLAN ID.

Explanation of the Options:

A. A router with only one available LAN port: This is correct. Subinterfaces allow a single physical interface to manage multiple networks, making it essential for routers with limited physical interfaces.

B. A firewall performing deep packet inspection: Firewalls can use subinterfaces, but it is not a requirement for deep packet inspection.

C. A hub utilizing jumbo frames: Hubs do not use subinterfaces as they operate at Layer 1 and do not manage IP addressing.

D. A switch using Spanning Tree Protocol: STP is a protocol for preventing loops in a network and does not require subinterfaces.

Conclusion:

Subinterfaces provide a practical solution for routing between multiple VLANs on a router with limited physical interfaces. They allow network administrators to optimize the use of available hardware resources efficiently.

References:

CompTIA Network+ guide detailing VLAN configurations and the use of subinterfaces (see page Ref 9†Basic Configuration Commands).

Understanding Spanning Tree Protocol (STP):

STP is used to prevent network loops in Ethernet networks by creating a spanning tree that selectively blocks some redundant paths.

Default Priority Value:

Bridge Priority: STP uses bridge priority to determine which switch becomes the root bridge. The default bridge priority value for most switches is 32768.

Priority Range: The bridge priority can be set in increments of 4096, ranging from 0 to 61440.

Configuration and Verification:

When deploying a new switch, the network administrator can verify the bridge priority using commands such as show spanning-tree to ensure it is set to the default value of 32768.

Comparison with Other Values:

4096 and 8192: Lower than the default priority, indicating these would be manually configured for higher preference.

36684: A non-standard value, likely a result of specific configuration changes.

References:

CompTIA Network+ study materials on Spanning Tree Protocol and network configuration.

A CNAME (Canonical Name) record is used in DNS to alias one domain name to another. This means that newapplication.comptia.org can be made to resolve to the same IP address as by creating a CNAME record pointing newapplication.comptia.org to . SOA (Start of Authority) is used for DNS zone information, MX (Mail Exchange) is for mail server records, and NS (Name Server) is for specifying authoritative DNS servers.