CompTIA Network+ Preparation · lesson 12 of 30 · 25 min
Network Device Reference
The Network+ exam tests your ability to identify the correct device for a given scenario, understand what layer each operates at, and know when to use one device over another. This lesson covers all key network devices from Layer 1 through Layer 7.
IDS vs IPS
Proxy Types
Flashcard Drill
Hub Layer 1 — repeats signal to all ports, shared collision domain. Obsolete. Switch Layer 2 — forwards frames by MAC address, one collision domain per port. Router Layer 3 — routes packets between networks by IP address, separates broadcast domains. IDS Intrusion Detection System — passive, out-of-band, alerts only. IPS Intrusion Prevention System — inline, active, detects and blocks threats. Load balancer Distributes traffic across multiple servers for availability and performance. Reverse proxy Sits in front of servers — load balancing, SSL offload, caching. WLC Wireless LAN Controller — centrally manages lightweight APs. NAS Network Attached Storage — file-level storage over SMB/NFS. VPN concentrator Terminates VPN tunnels — IPsec or SSL/TLS.
Worked Scenario: Choosing the Right Device
Scenario
A company wants to monitor all traffic on their network for suspicious activity but cannot afford any impact on network performance if the monitoring system fails. Which device should they deploy, and how?
Answer: IDS (Intrusion Detection System) deployed out-of-band via a network tap or SPAN port. An IDS is passive — it receives a copy of traffic and alerts on suspicious activity without being in the traffic path. If the IDS fails, traffic continues unaffected. An IPS would be inline and could block legitimate traffic on false positives, and a failure could disrupt the network.
If the company later wants active blocking, they can add an IPS inline — but for monitoring-only with zero performance risk, IDS out-of-band is correct.
Knowledge Check — 12 Questions
Network Devices (Network+)
Which device operates at Layer 2 and forwards frames based on MAC addresses?
- Router
- Hub
- Switch
- Firewall
Answer: Switch
Switches operate at Layer 2 and use MAC address tables to forward frames.
An IDS differs from an IPS because an IDS:
- Blocks traffic inline
- Only alerts — does not block
- Operates at Layer 1
- Replaces a firewall
- Answer: Only alerts — does not block
IDS is passive and out-of-band — it detects and alerts but cannot block traffic.
Which device distributes incoming traffic across multiple servers?
- Proxy server
- Load balancer
- VPN concentrator
- IPS
Answer: Load balancer
A load balancer distributes traffic across servers for high availability and performance.
A _____ proxy sits in front of servers and provides load balancing and SSL offload.
Answer: reverse
A reverse proxy sits server-side — it provides load balancing, SSL termination, and caching.
Which device terminates IPsec VPN tunnels?
- Load balancer
- IDS
- VPN concentrator
- Proxy server
Answer: VPN concentrator
A VPN concentrator terminates VPN tunnels — IPsec or SSL/TLS.
A hub creates a separate collision domain for each port.
- True
- False
Answer: False
A hub has ONE shared collision domain. Switches create one per port.
A Wireless LAN Controller (WLC) manages which type of access points?
- Autonomous APs
- Lightweight APs (LWAP)
- Mesh APs
- All of the above
Answer: Lightweight APs (LWAP)
WLCs manage lightweight APs — the APs tunnel traffic to the WLC for centralized management.
Which storage type provides file-level access over SMB or NFS?
- SAN
- NAS
- DAS
- iSCSI
Answer: NAS
NAS (Network Attached Storage) provides file-level storage over SMB (Windows) or NFS (Linux).
A multilayer switch differs from a regular switch because it can:
- Connect more devices
- Route packets between VLANs at Layer 3
- Operate at Layer 1
- Replace a firewall
- Answer: Route packets between VLANs at Layer 3
A multilayer (Layer 3) switch can route between VLANs using SVIs — faster than router-on-a-stick.
An IPS is placed _____ in the traffic path to actively block threats.
Answer: inline
IPS is inline — all traffic passes through it, allowing it to drop malicious packets in real time.
A company needs network monitoring with zero risk of disrupting traffic if the monitoring device fails. Which should they use?
- IPS inline
- IDS out-of-band
- Firewall
- Load balancer
Answer: IDS out-of-band
IDS is passive and out-of-band — if it fails, traffic is unaffected. IPS inline would disrupt traffic on failure.
Which device provides block-level storage over a network using iSCSI or Fibre Channel?
- NAS
- SAN
- DAS
- NFS
Answer: SAN
SAN (Storage Area Network) provides block-level storage — used for high-performance database and VM storage.
Previous lesson: Wireless standards: 802.11a/b/g/n/ac/ax, channels, WPA2/WPA3, SSID, BSSID
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