SOHO Networks — 220-1201 Study Guide

Bundled into the existing CompTIA A+ Core 1 premium course — no separate purchase.

14-day money-back guarantee — no questions asked.

Included in this chapter:

Aspect	DHCP (dynamic)	DHCP reservation	Static (manual)
Who assigns it	DHCP server, any free address from the scope	DHCP server, fixed to the device MAC	You, typed on the device itself
Stable over time?	No, can change at each lease renewal	Yes, always the same IP	Yes, until you change it
Configured where	Nothing on the client	Centrally on the router/DHCP server	Locally on each device
Best for	Laptops, phones, general clients	Printers, NAS, port-forward targets	The router, servers, infrastructure
Managing many devices	Lowest effort, fully automatic	Low, one console lists every reservation	Highest effort, per-device and error-prone

Cheat sheet

Every IPv4 host needs an IP, subnet mask, default gateway, and DNS server
The subnet mask splits an address into network and host, and /24 equals 255.255.255.0
Without a default gateway a host reaches only its own subnet
Misconfigured DNS breaks names while numeric IPs still work
RFC 1918 reserves three private IPv4 ranges for internal use
NAT lets many private hosts share one public IP address
DHCP leases addresses to clients from a defined scope
A DHCP client gets its lease through the DORA exchange
A DHCP reservation pins an IP by MAC; a static address is set on the device
Put static addresses outside the DHCP scope to avoid conflicts
Point a port forward at a device with a reserved or static IP
Forward a single port rather than exposing a host in the DMZ
UPnP opens port forwards automatically, which is a security risk
Choose WPA3, fall back to WPA2 with AES, and never WEP or original WPA
WPA3-Personal uses SAE to block offline password cracking
On a WPA2 network choose AES, not the legacy TKIP cipher
Put visitors and IoT devices on an isolated guest network
Hiding the SSID is tidiness, not real security
MAC filtering is easily defeated by spoofing
Change the router's default administrator password first
IPv6 addresses are 128-bit, written in colon-separated hex
IPv6 needs no NAT and can self-configure with SLAAC
A client VPN tunnels a remote device onto the private network
A full tunnel routes all traffic; a split tunnel only the private-network traffic

Unlock with Premium — includes all practice exams and the complete study guide.