N10-009 Exam Dumps - CompTIA Network+ Questions and 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).

BGP (Border Gateway Protocol) is used for routing data between different ISPs, making it essential for the functioning of the internet. Its primary use is for exchanging routing information between autonomous systems, especially different ISPs. Preventing loops within a LAN is handled by protocols like Spanning Tree Protocol (STP), while improving reconvergence times and sharing routes with a Layer 3 switch are functions of other protocols or internal mechanisms.

•nslookup allows querying DNS records to verify if the new server is correctly resolving domain names.

•ping (A) tests basic connectivity, not DNS configuration.

•tracert (B) shows network path latency but doesn’t test DNS.

•tcpdump (C) captures packets but isn’t ideal for DNS verification.

????Reference: CompTIA Network+ N10-009 Official Documentation – DNS Testing Tools.

To change where the outside DNS records are hosted, the network administrator needs to update the NS (Name Server) records at the domain registrar. NS records specify the authoritative name servers for a domain, directing where DNS queries should be sent.

NS (Name Server) Records: These records indicate the servers that are authoritative for a domain. Changing the NS records at the registrar points DNS resolution to the new hosting provider.

SOA (Start of Authority): Contains administrative information about the domain, including the primary name server.

PTR (Pointer) Records: Used for reverse DNS lookups, mapping IP addresses to domain names.

CNAME (Canonical Name) Records: Used to alias one domain name to another, not relevant for changing DNS hosting.

Network References:

CompTIA Network+ N10-007 Official Certification Guide: Discusses DNS records, their purposes, and how to manage them.

Cisco Networking Academy: Provides training on DNS management and the role of different DNS record types.

Network+ Certification All-in-One Exam Guide: Explains DNS records and their configuration for domain management.

Out-of-band (OOB) management refers to using a dedicated management network that is physically separate from the regular data network. This management network uses a different set of IP addresses to ensure that management traffic is isolated from user data traffic, providing a secure way to manage network devices even if the main network is down or compromised.References: CompTIA Network+ study materials. ​

A split-tunnel VPN allows certain traffic (e.g., cloud-based services) to bypass the VPN and go directly to the Internet. This reduces the amount of traffic that needs to traverse the company's VPN and Internet connection, conserving bandwidth and reducing costs. It also means that not all traffic is subject to the same level of inspection or filtering, which can improve performance for cloud-based services.References: CompTIA Network+ study materials.