📌 Problem Overview

When trying to access a local router via Chrome on macOS using the address http://192.168.3.1, Chrome displays an error like:

• “This site can’t be reached”
• “ERR_ADDRESS_UNREACHABLE”

However:

• ✅ Safari can access the router without issue
• ✅ The network is fully functional
• ✅ Ping to the IP works perfectly via Terminal

This strongly suggests Chrome-specific behavior is at play.

🔍 Initial Troubleshooting Attempts

✅ Attempt 1: Reinstalling Chrome

• Uninstalled and reinstalled Chrome from scratch
• ❌ Chrome still cannot access 192.168.3.1

✅ Attempt 2: Resetting Chrome Settings

• Cleared all browser data and cache
• Restored settings to default
• ❌ Still unable to connect

✅ Attempt 3: Launch Chrome with Command-Line Flags

🎉 Success! Chrome can now access http://192.168.3.1 Confirms that network is not the issue — Chrome’s runtime mode is

🤯 New Issue: Works Once, Fails the Next Time

After packaging the command into an .app launcher, it works the first time but fails on subsequent runs with the same error.

🔬 Root Cause Analysis

❗ Chrome’s Default Security Mechanisms

Chrome includes several built-in protections that can interfere with local network access:

Feature	Description
Site Isolation	Separates sites into processes to prevent data leaks
Strict CORS	Enforces strict origin policies, even on local IPs
Sandbox Networking	Limits network access from subprocesses
Web Security	Blocks insecure origin access to local/private IPs

These mechanisms can block access to 192.168.x.x addresses under certain conditions.

❗ Conflict with --user-data-dir

Using a custom user data directory (e.g., /tmp/chrome-router) can cause Chrome to:

• Create lock files
• Cache session data
• Refuse to launch if the previous session didn’t exit cleanly

That’s why it works the first time, but fails on subsequent launches.

✅ Solutions

✅ Solution 1: Clean the User Data Directory Before Launch (Recommended)

Modify the script to delete the previous data directory before launching Chrome:

AppleScript Example:

do shell script "rm -rf /tmp/chrome-router && mkdir -p /tmp/chrome-router && /Applications/Google\\ Chrome.app/Contents/MacOS/Google\\ Chrome --disable-web-security --disable-features=IsolateOrigins,site-per-process --user-data-dir='/tmp/chrome-router' http://192.168.3.1 &> /dev/null &"

✅ Ensures a clean Chrome instance every time

✅ Solution 2: Use a Unique Directory Each Time (Dynamic)

Generate a new temporary directory using a timestamp:

✅ Avoids conflicts
⚠️ Leaves multiple folders under /tmp

do shell script "rm -rf /tmp/chrome-router && mkdir -p /tmp/chrome-router && /Applications/Google\\ Chrome.app/Contents/MacOS/Google\\ Chrome --disable-web-security --disable-features=IsolateOrigins,site-per-process --user-data-dir='/tmp/chrome-router' http://192.168.3.1 &> /dev/null &"

✅ Solution 3: Use Lightweight Logging Mode

This simpler command can also work (though less reliable):

/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --enable-logging --v=1 http://192.168.3.1

⚠️ Sometimes works due to relaxed internal handling in debug mode

🧰 Packaging as a .app Launcher

You can use macOS’s Script Editor to wrap the above into a double-clickable .app:

1. Open Script Editor
2. Paste your script (see above)
3. Go to File → Export
4. Choose Application as file type
5. Name it something like Open Router.app
6. Save to Desktop or Applications

📋 Bonus Check: Chrome Policy Status

Open chrome://policy to ensure Chrome is not managed by enterprise policies:

• ✅ No policies set = Good
• ❌ If policies exist, Chrome might be restricted by MDM or system config

✅ Summary

Item	Status
macOS Network	✅ Normal
Safari Access	✅ Works
Chrome Default Access	❌ Blocked
Chrome w/ Flags	✅ Works
Second Run Fails	❌ Due to user data directory conflict
Final Solution	✅ Clear or rotate user-data-dir each run

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📎 Final Script (Recommended)

do shell script "rm -rf /tmp/chrome-router && mkdir -p /tmp/chrome-router && /Applications/Google\\ Chrome.app/Contents/MacOS/Google\\ Chrome --disable-web-security --disable-features=IsolateOrigins,site-per-process --user-data-dir='/tmp/chrome-router' http://192.168.3.1 &> /dev/null &"

🧠 Key Takeaways

• If Chrome can’t access local IPs but Safari can, it’s likely a browser security config issue
• Use command-line flags to disable security features only for local access
• Always clean or rotate --user-data-dir to avoid session conflicts
• Package your script into a .app for convenience

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📌 Optional: Prompt for IP Address (Dynamic Input)

If you want to enter the IP each time:

set ipAddress to text returned of (display dialog "Enter IP Address to Access:" default answer "192.168.3.1")
do shell script "rm -rf /tmp/chrome-router && mkdir -p /tmp/chrome-router && /Applications/Google\\ Chrome.app/Contents/MacOS/Google\\ Chrome --disable-web-security --disable-features=IsolateOrigins,site-per-process --user-data-dir='/tmp/chrome-router' http://" & ipAddress & " &> /dev/null &"