CompTIA Network+ N10-009 CompTIA Study Notes

The requirement is to support over 300 hosts. The subnet mask 255.255.254.0 (or /23) provides 512 addresses, 510 of which are usable — ideal for around 300 devices.

255.255.0.0 (/16) provides too many addresses.

255.255.192.0 (/18) gives 16384 addresses — overkill.

255.255.255.254 is invalid for host assignments (only 2 addresses, 0 usable).

From Andrew Ramdayal’s guide:

“To support 300 hosts, a /23 subnet (255.255.254.0) offers 510 usable addresses — the most efficient choice without excessive overhead.”

Port 22 is used for Secure Shell (SSH), which enables encrypted remote login and command execution on network devices.

Port 23 = Telnet (unencrypted)

Port 80 = HTTP

Port 123 = NTP

From Andrew Ramdayal’s guide:

“SSH uses port 22 to provide secure command-line access to devices such as switches and routers. Unlike Telnet (port 23), SSH encrypts session traffic, making it the preferred method for remote administration.”

Comprehensive and Detailed Explanation (paraphrased, aligned to N10-009):

An evil twin is a malicious wireless access point that impersonates a legitimate SSID. Once victims connect, the attacker can intercept and manipulate traffic, performing an on-path (man-in-the-middle) attack—capturing credentials, injecting content, or downgrading encryption.

B. DDoS overwhelms services with traffic; it’s not the typical follow-on from clients joining a rogue AP.

C. ARP spoofing is another way to become on-path on wired segments, but with an evil twin, the wireless association itself enables the on-path position.

D. Phishing is social engineering; while an evil twin could be used to present fake portals, the primary technical posture after connection is on-path.

References (CompTIA Network+ N10-009):

Domain: Network Security — Wireless threats (rogue APs/evil twins), traffic interception, on-path attacks.

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Understanding Link Aggregation:

Definition: Link aggregation combines multiple network connections into a single logical link to increase bandwidth and provide redundancy.

Usage in High-Bandwidth Scenarios:

Combining Links: By aggregating multiple 1Gbps connections, the facility can utilize the full 2.5Gbps bandwidth provided by the ISP.

Benefits: Enhanced throughput, load balancing, and redundancy, ensuring better utilization of available bandwidth.

Comparison with Other Options:

802.1Q Tagging: Used for VLAN tagging, which does not affect the physical bandwidth utilization.

Network Address Translation (NAT): Used for IP address translation, not related to link speed or bandwidth aggregation.

Port Duplex: Refers to the mode of communication (full or half duplex) on a port, not the aggregation of bandwidth.

Implementation:

Configure link aggregation (often referred to as LACP - Link Aggregation Control Protocol) on network devices to combine multiple physical links into one logical link.