Guest Network Isolation

Guest Network Isolation

Guest Network Segregation May Be Just Theater

• Guest Network matters.
• Never give your local network credentials (password) to guests. 
• Guest Network must be true isolation,
  not just a 2nd network name (SSID).
• Without isolation:
• The very real threat is credential sharing (which often happens casually).
• Guest network can give the world access to all your networked devices.
• That can facilitate identity theft, accidental or deliberate.
• ASUS gets this right:
• Guests cannot access your local networked devices.
• Guests cannot see each other.
• Guests cannot cross sub-networks.
• If your router does not enforce that, then it does not have a real guest network.

How To Safely Share a Wireless Printer

• Tell your guest to use AirPrint or Wi-Fi Direct.

How to Safely Share a Wireless TV

• Tell your guest to use AirPlay or Miracast. 

How To Test Guest Network Isolation

1. Power on all devices (computers, printers, phones, smart home) on your local network (wired and wireless).
2. Connect to your Guest Network with an Apple or Android smartphone.
3. Install and Run Fing from the appropriate app store (Apple, Google, Microsoft).
4. If you see more than 1 device (your phone) in the Devices tab, the Guest Network is not isolated.

 

Powered Toothbrush Bargain

Li-ion Rechargeable AA Batteries

Li-ion rechargeable AA battery is the secret!

There are many different powered toothbrushes on the market, ranging from inexpensive battery powered to expensive rechargeable models.

In truth, there is no meaningful difference in cleaning action between the best inexpensive battery powered models with fresh batteries and the expensive rechargeable models. The principal difference is the power source.

Inexpensive battery powered toothbrushes typically use disposable AA or AAA batteries, an ongoing cost and waste issue. Worse, as the disposable battery discharges, the voltage drops and the toothbrush slows down.

Oral-B 3D Battery Toothbrush

The solution is to use the latest Li-ion technology in standard AA format, ideally with USB-C recharging!

• Constant battery voltage = constant brushing power 
• High battery power capacity
• Long battery life (1,000 recharges)
• Quick, convenient battery recharging 
• Li-ion tech is superior to older NiMH (and NiCd) tech

Recommended Products

1. Oral-B 3D White Battery Toothbrush 
2. CARDIENS AA USB rechargeable batteries 
3. Toothpaste Worth the Money 

Moral: Why spend $100-$200 instead of only $10-$20?!

Toothpaste Worth the Money

Colgate Optic White

The Toothpaste Gimmick

Most "whitening" toothpastes on the market are a marketing illusion. They don't bleach away stains—they just clean with mild abrasives.

Colgate Optic White (Advanced & Pro Series) is what actually works:

• Real Whitening: Uses hydrogen peroxide to safely bleach away stains.
• 5% Pro: Powerful starter. One tube is all you need.
• 2% Advanced: Perfect for ongoing use.
• No Oral Health Compromise: Includes cleaning agents and cavity protection.
• Smart Tube Design: Engineered to keep out air for better product and less waste.

Moral: Pay for actual chemistry and tube design, not marketing fluff.

p.s. Don't fall for the Colgate Optic White Pro Series Powered Toothbrush—
it's not as good as the Oral-B 3D White Battery Toothbrush.

Amazon Pricing Alert

Amazon Pricing

Amazon pricing is increasingly a ripoff

Real example: Mann engine air filter for 2008 Volvo S60 2.5T:

• FCP Euro: $18.43
• Amazon:*  $24.95 (35% more)

 * Sold and shipped by Amazon, not a 3rd party. 

Amazon's Dynamic Pricing 

• Demand pricing: Boosts prices for return buyers or strong demand
• Location pricing: Charges more if you are in an affluent area.
• Prime premium: Folds shipping cost into prices. 
• Project Nessie: Secret testing of how much it could charge. 

Moral: Always price check!

 

USB-C Cable Conundrum

USB-IF logo

USB-IF Certification is Important

You need a new USB-C to USB-C cable, but you don't want just any old cable. You want:

1. Soft and flexible
2. Solid and reliable 
3. 60W fast charging

And you don't want it to crap out quickly. 

The problem is that so many reasonably priced USB-C cables not only fail to measure up to those criteria, but also that so few (even top brands) are certified USB-IF (USB Implementers Forum), important because it ensures that cables meet strict performance and safety standards.  If a cable doesn't have the official USB-IF logo on it, it's not certified.

The good news is that you can easily find certified USB-C cables on Amazon under Amazon Basics branding, e.g., Amazon Basics USB-C to USB-C 2.0 Fast Charging Cable, 60W, 480Mbps Speed, USB-IF Certified

• USB-IF Certifed 
• Various lengths 
• High quality 
• Low cost
• Black or white

Important Notes:

1. Watch out for counterfeits, especially no name cables. You can check here.
2. Watch out for "fast charging" cables that are only 15W.
3. 60W cables are powerful enough for most purposes and tend to be more flexible than 100W.
4. Faster cables (> USB 2.0) tend to be less flexible and may not be needed. 

Best Free AI in 2026

Best Free AI in 2026

Free Artificial Intelligence Tools

The free tiers of today’s AI tools vary wildly in reliability. Some are excellent for fast lookup and synthesis, others collapse under multi‑step reasoning or lose context. These are the ones that consistently deliver value without a subscription:

Copilot (Microsoft, free tier)

• Pro: Good on small reasoning tasks and rewriting text; Microsoft integration.
• Con: Chat responses are often generic or shallow; can hallucinate.

Duck.ai (free)

• Pro: Model choices; good for privacy-focused quick factual answers and short summaries.
• Con: Not suitable for long‑form reasoning or multi‑step tasks.

Perplexity (free tier) 

• Pro: Best-in-class for grounded answers with citations.
• Con: Free tier now requires login to chat.

Gemini (Google, free tier)

• Pro: Strong at multimodal tasks (images, screenshots, UI reasoning).
• Con: Repeats mistakes unless tightly constrained; often hallucinates.

Pick the best tool for the task:

• Accuracy: Perplexity
• Reasoning: Claude Haiku 4.5 (via Duck.ai)
• UI/multimodal: Gemini
• Autocomplete: Copilot
• Privacy‑first quick answers: GPT-4o mini (via Duck.ai)

Save & Sync Passwords

Safe Cross-device Password Sync

Safe Cross-device Password Sync

So you've smartly avoided closed-source proprietary password managers in favor of a good free open-source (FOSS) password manager, and you now need to safely sync your passwords between your devices. The best way to do that, given Internet access, is to store securely-encrypted password data in the cloud, which also provides essential backup. (You just need to memorize one unique secure password for that task. All other passwords are available in your password manager.)

My recommended approach:

Computer 

Setup Google Drive to Mirror (or Stream) between your computer and the cloud.
This approach is also supported by other cloud providers (e.g., OneDrive, Dropbox). 
Save your password file there locally and it will be automatically synced to the cloud.
Makes it easy to access with your computer password manager (e.g., KeePass). 

Android

Directly access your password file using Android Storage Access Framework (SAF), which
supports Google Drive and other cloud document providers (e.g., OneDrive, Dropbox).
making it securely accessible to standard Android apps (e.g., Keepass2Android).

Tips

1. With Google Drive set to Stream, be sure to set "Available offline" on your password file.
2. KP2A Tile is a handy app that launches Keepass2Android from a Notification Tile. 

<<>>

Keep Windows Apps Updated

UniGetUI

UniGetUI (formerly WingetUI)

Windows Update keeps your Windows updated, but not your Windows tools and apps, which are left to fend for themselves, making for a big chaotic hassle. There are command-line tools to facilitate updates, but they are too painful for ordinary humans. Fortunately there is a good GUI tool to manage and automate the command-line tools: UniGetUI. It's not perfect, but it can be quite helpful in keeping your system updated.

UniGetUI Highlights

• Install, update & remove: One-click install, update, and uninstall. 
• Update options: Automatically update packages, or be notified when updates become available.  
• Bulk operations: Bulk-install, update, or uninstall multiple packages at once.
• Discover & filter packages: Search and filter packages across all supported managers. 
• Export & backup: Export package lists to import on another machine. Backup your setup to recover in seconds when migrating.

Important Tips 

1. Rely mostly on Winget (official Microsoft source) as a package source.
   Other sources should be used only in special circumstances.
2. Be careful to select only the best package for a given app. Quality can and does vary. 
3. Do not install updates automatically. Check carefully before updating.
4. Do not use it to update apps that can update themselves (e.g., Web browsers).
5. UniGetUI works best for newer 64-bit apps, is not safe for many older Win32 apps.
6. Uninstalls can leave debris or broken apps. Just use UniGetUI for updates. 

Fixing Sony WF-1000XM4 earbuds

Sony WF-1000XM4 earbuds

Sony WF-1000XM4 earbuds

Almost perfect:

• Outstanding sound quality
• Exceptional noise canceling 
• Clear calling
• beamforming microphone
• bone-conduction sensor
• IPX42 Water resistance 
• Up to 8 hours battery life with noise canceling

What makes it "almost" is that last bullet, because the WF-1000XM4 quickly became notorious for battery problems, with dismal battery life and unequal earbud charging. 

ZeniPower Z55H CCC battery

The good news is that the battery problem can be fixed by replacing the batteries with genuine ZeniPower Z55H batteries. (Be sure to get the ones marked CCC,* not a generic alternative.) Then:

• DIY: Sony WF-1000XM4 Wireless Earbuds Battery Replacement - iFixit Repair Guide
  -or-
• Have a good electronics repair place install them.  

When complete, you'll have outstanding battery life to go along with the outstanding performance!

Note: There are now Sony WF-1000XM5 earbuds without the battery problem, but the user interface and form factor are not as good as the XM4 and the other changes are too minor to matter. Stick with the XM4.

 * CCC‑marked ZeniPower Z55H cells use a revised formulation with slightly lower nominal capacity (270 mWh vs 290 mWh) but with more reliable life and stability. 

Bluetooth Mouse by Lenovo

Lenovo WL300 Bluetooth Mouse

Lenovo Bluetooth Silent Mouse WL300

It's surprisingly hard to find a good (responsive, comfortable) Bluetooth mouse at a decent price point, but the Lenovo Bluetooth Silent Mouse WL300 fills the bill:

• Convenient Bluetooth connection with SwiftPair
• 5-button mouse with silent left and right clicks​
• Sculpted grip for all day comfort
• Sleek and compact 
• 3-level DPI adjustment: 800, 1200, and 1600 DPI 
• Works on many surfaces​
• Long-lasting durability and consistent performance 
• Available in both grey and white color
• Powered with a single AA battery 

Tips

1. Use a Lithium USB-C Rechargeable AA battery
2. Adjust button behavior with X-Mouse Button Control
3. Currently less than $20 on Amazon