comptia-a-plus-core2/notes/SEC-10-soho-network-security.md

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# SEC-10: SOHO Network Security
Status: not started
Domain:
- 2.0 Security
Objective alignment:
- 2.10 SOHO network security
## What You Need To Know
SOHO means Small Office/Home Office. On the exam, this usually means a small router or wireless access point that combines routing, switching, firewall, and Wi-Fi.
Your job is to harden the router so attackers cannot easily control it, join the wireless network, or open paths into the network.
Core protections:
- Change default admin credentials
- Update firmware
- Use WPA2/WPA3 encryption
- Disable UPnP unless required
- Disable remote management unless required
- Use guest networks carefully
- Place network equipment securely
- Use content/IP filtering when needed
## Memory Trick
Use **P-F-W-U-G**:
- **P**asswords: change defaults
- **F**irmware: keep updated
- **W**i-Fi: WPA2/WPA3, not open
- **U**PnP: usually disable
- **G**uest: disable or isolate and secure
Shortcut:
- **If it manages the network, protect the login first.**
## Default Passwords
Routers and access points often ship with known default usernames and passwords.
Why it matters:
- Admin access gives full control of the device.
- Defaults are easy to find online.
- Attackers can change DNS, Wi-Fi settings, firewall rules, and port forwarding.
Best practice:
- Change the admin password during setup.
- Use a strong unique password.
- Store it in a password manager if possible.
## Firmware Updates
Firmware is the router's built-in software.
Updates can include:
- Security patches
- Bug fixes
- Stability fixes
- New features
Exam clue:
- If a router has known vulnerabilities, update firmware from the manufacturer.
## Secure Management Access
Router management access should be limited.
Good settings:
- Strong admin password
- Multifactor authentication if available
- Local management only
- Disable Internet-facing remote administration unless required
- Limit management access by IP address if supported
Cloud management:
- Some routers use cloud accounts.
- Protect the cloud account with a strong password and MFA.
Exam clue:
- If a question says management is exposed to the Internet, disable remote management or restrict access.
## Wi-Fi Security
SSID:
- The wireless network name.
- Change obvious default names such as LINKSYS or NETGEAR.
- Do not use personal information in the SSID.
SSID broadcast:
- Hiding the SSID is not strong security.
- The SSID can still be discovered with wireless tools.
- Use real encryption instead.
Encryption:
- Open network: no password, weak security.
- WPA2-Personal or WPA3-Personal: common SOHO choice with a pre-shared key.
- WPA2/WPA3-Enterprise: uses individual user authentication with a server, usually in larger organizations.
Best SOHO choice:
- WPA3-Personal when supported.
- WPA2-Personal if WPA3 is not available.
- Strong Wi-Fi passphrase.
## UPnP
UPnP means Universal Plug and Play.
What it does:
- Lets internal apps/devices automatically open inbound ports on the router.
- Common with gaming, media, and peer-to-peer apps.
Risk:
- Apps may open ports without approval.
- This can expose internal services to the Internet.
Best practice:
- Disable UPnP unless a required app needs it.
## IP Filtering and Content Filtering
Allow list:
- Only approved traffic or destinations are allowed.
- More restrictive.
Deny list:
- Blocks known bad traffic, sites, domains, or IPs.
- More flexible but less strict.
Content filtering:
- Blocks traffic by URL, category, malware reputation, or content type.
- Used for parental controls, business policy, and malware protection.
Exam clue:
- If the goal is to block inappropriate websites, use content filtering.
- If the goal is to permit only known systems or destinations, use an allow list.
## Screened Subnet
A screened subnet is a separate network area for public-facing services.
Older term:
- DMZ
Purpose:
- Keeps public systems separated from the internal private network.
- Adds a layer between the Internet and internal devices.
SOHO example:
- A router may have a DMZ host option.
- Be careful: placing a device in a DMZ can expose it heavily.
## Guest Networks
Guest networks can be useful, but they must be controlled.
Best practice:
- Disable guest network if not needed.
- If enabled, use WPA2/WPA3.
- Isolate guests from internal devices.
- Use a separate password.
Common uses:
- Visitors
- IoT devices
- Lab or test devices
Exam clue:
- If visitors need Internet but should not access internal PCs, use an isolated guest network.
## Physical Placement
Network devices should be physically protected.
Reasons:
- A person with physical access may reset the router.
- A person may unplug cables or connect unauthorized devices.
- Wireless access points need good placement for coverage.
Best practice:
- Keep routers, switches, and access points in a secure location.
- Place wireless access points high and central when possible.
- Plan power and access for maintenance.
## Commands To Enter
These commands inspect your local network. They do not change router settings.
Windows PowerShell:
```powershell
ipconfig
```
What it does:
- Shows IP address information.
- Look for Default Gateway; that is usually your router.
```powershell
Get-NetConnectionProfile
```
What it does:
- Shows the current network profile.
- Public is more restrictive; Private is used for trusted local networks.
```powershell
netsh wlan show interfaces
```
What it does:
- Shows Wi-Fi connection details, including SSID and authentication type.
Linux:
```bash
ip route
```
What it does:
- Shows the default route.
- The `default via` address is usually your router.
```bash
nmcli dev wifi list
```
What it does:
- Lists nearby Wi-Fi networks if NetworkManager is installed.
- Shows SSIDs and security types.
```bash
nmcli connection show --active
```
What it does:
- Shows active network connections.
macOS:
```bash
route -n get default
```
What it does:
- Shows the default gateway router.
```bash
networksetup -getairportnetwork en0
```
What it does:
- Shows the connected Wi-Fi network on many Macs.
- Some Macs may use a different interface than `en0`.
```bash
system_profiler SPAirPortDataType
```
What it does:
- Shows detailed Wi-Fi information.
Do not log in to a router you do not own or administer. Do not change router settings in this section unless you understand the impact.
## Quick Checks
You should be able to answer:
- Why change default router passwords?
- Why keep firmware updated?
- Why is WPA2/WPA3 better than an open network?
- Why is hiding the SSID not strong security?
- Why is UPnP risky?
- When should you use a guest network?
- What is the purpose of a screened subnet?