Connectivity Troubleshooting explains how to isolate proxy connection failures before you move into application debugging, browser automation debugging, or destination-specific analysis.
This guide is written for developers, scraping engineers, automation engineers, and technical operators who need a disciplined way to determine whether a failure is caused by proxy endpoint details, authentication, environment mismatch, local network conditions, or broader service availability.
When a proxy request fails, the most important rule is simple: reduce the problem to one proxy, one authentication method, one environment, and one minimal request.
What This Page Is For
Use this page when:
- a proxy request does not connect at all
- a request hangs or times out before returning a useful response
- a browser appears configured but traffic is not leaving through the proxy path
- one machine works and another does not
- a previously working setup suddenly stops connecting
- you are not yet sure whether the problem is local, authentication-related, environment-related, or service-level
This page is about basic path establishment. It is not mainly about target-site bans, CAPTCHA behavior, browser fingerprinting, or scraping logic.
The Right Troubleshooting Principle
Do not start with your full application.
Do not start with a crawler.
Do not start with browser automation.
Start with the smallest possible request from the exact environment you plan to use.
A connectivity problem should always be reduced to:
- one proxy IP
- one port
- one authentication method
- one machine or runtime environment
- one minimal request
If that baseline is not working, larger frameworks only add noise.
Start with a Minimal Baseline Test
The cleanest first test is a direct request to the IP check endpoint.
If You Are Using IP Whitelist Authentication
curl -x http://PROXY_IP:PORT http://checkip.instantproxies.com/
If You Are Using Username and Password Authentication
curl -x http://USERNAME:PASSWORD@PROXY_IP:PORT http://checkip.instantproxies.com/
Replace the placeholders with the exact values from your dashboard.
Do not add retries, scraping logic, session logic, browser options, or application-specific code yet.
What a Healthy Result Looks Like
A healthy baseline request should:
- connect successfully to the proxy endpoint
- return an outbound IP through the proxy path
- behave consistently from the same environment
Expected output usually looks like:
IP=YOUR_PROXY_IP
If you do not get a result like this, the path is not yet verified.
Troubleshoot in This Order
The fastest way to solve connectivity problems is to work from the lowest-complexity checks upward.
1. Confirm the Exact Proxy IP and Port
Start by confirming that the proxy IP and port were copied correctly from the dashboard.
This is one of the most common first-time errors. A single wrong digit in the proxy IP or an incorrect port is enough to make the request fail.
If your setup allows more than one supported port for the same proxy endpoint, test one known port first and only then try another supported port in a controlled way.
2. Confirm the Authentication Method
InstantProxies supports both:
- IP whitelisting or authorization
- username and password authentication
Before changing anything else, confirm which method you are actually using for the environment under test.
If using IP whitelisting, confirm:
- the public source IP of the environment is authorized
- the request is being sent from that same environment
- you are not unintentionally testing from another machine, server, container, or runner
If using username and password authentication, confirm:
- the username is copied exactly
- the password is copied exactly
- the credentials are inserted into the proxy request correctly
- the request is not being tested as if IP authorization were the active model
A large percentage of setup failures are simply the result of testing the wrong authentication model.
3. Confirm the Actual Source Environment
Many connectivity failures are really environment mismatches.
You should be able to answer clearly:
- which machine is sending the request
- whether the request is coming from a local workstation, server, VM, container host, or CI runner
- whether that environment matches the one you intended to test
This matters because a proxy can work from one environment and fail from another even when the proxy endpoint itself is healthy.
4. Test Outside the Application
If your application is failing, repeat the test outside the application with cURL.
This helps answer the most important diagnostic question early:
- is the failure in the proxy path itself
- or only in the application, framework, browser, or automation layer
If cURL works but the application fails, the proxy path is probably healthy and the problem now belongs to the client configuration or runtime behavior.
5. Check Whether the Failure Is General or Destination-Specific
Once the baseline path is proven or partially proven, compare simple endpoints against the real destination.
A useful sequence is:
- test the IP check endpoint
- test another simple target
- test the real destination only after the baseline path is working
If the proxy works on simple endpoints but fails only on one destination, the issue may no longer be a basic connectivity problem.
6. Test from Another Machine or Network
If possible, repeat the same minimal request from another environment.
This is one of the fastest ways to separate:
- local firewall problems
- router or ISP issues
- machine-specific misconfiguration
- environment-specific authentication problems
- service-wide issues
If IP whitelisting is being used, make sure the alternate environment is authorized before drawing conclusions.
7. Use the Dashboard Test Tools
If the dashboard includes a proxy test tool, use it as a second-layer check.
This does not replace real request verification, but it helps answer whether the assigned proxy appears responsive from the service side.
If the dashboard test looks healthy while your local request still fails, the issue is more likely to be in:
- request formatting
- authentication setup
- local network conditions
- environment mismatch
8. Check Network Status
If a setup that previously worked suddenly becomes unstable, check the public network status page.
Use this step when:
- multiple proxy entries seem to fail together
- a good setup stops working unexpectedly
- you want to rule out broader service instability before changing your implementation
Common Connectivity Failure Patterns
Pattern 1: Nothing Connects at All
Possible causes include:
- wrong proxy IP
- wrong port
- wrong authentication method
- unauthorized source IP
- incorrect credentials
- local firewall or network blocking
- testing from the wrong environment
Best next move: return to the minimal cURL test and verify endpoint, port, authentication method, and source environment one by one.
Pattern 2: The Dashboard Test Looks Fine but Your Request Fails
Possible causes include:
- incorrect local request format
- wrong authentication method
- environment mismatch
- local network restrictions
Best next move: confirm the request format and the exact environment sending the request.
Pattern 3: cURL Works but the Application Fails
Possible causes include:
- incorrect proxy configuration in the application
- credentials placed incorrectly in the client library
- proxy settings not being applied consistently across all requests
- framework-specific timeout or transport behavior
Best next move: compare the application setup directly against the known-good cURL request.
Pattern 4: One Environment Works but Another Does Not
Possible causes include:
- source IP mismatch
- stale allowlist assumptions
- credential mismatch in one environment
- OS, browser, or runtime-specific configuration differences
Best next move: verify authentication and source environment independently for each runtime.
Pattern 5: It Worked Before but Suddenly Fails
Possible causes include:
- source IP changed
- authentication settings changed
- environment drift
- local infrastructure change
- destination-side change
- broader service instability
Best next move: re-run the minimal test, re-check dashboard settings, and review network status before making large changes.
Common Mistakes During Connectivity Troubleshooting
The most common troubleshooting mistakes are:
- changing multiple variables at once
- jumping into framework debugging before proving the minimal request path
- assuming browser configuration proves network routing
- assuming the dashboard alone proves runtime success
- testing from the wrong machine or environment
- mixing authentication methods accidentally
- assuming the destination is blocking you before baseline connectivity is proven
The safest method is always the same: reduce complexity until one request either works or fails for a clearly understood reason.
What to Collect Before Contacting Support
If the issue is still unresolved, collect these details before opening a support request:
- the exact proxy IP and port tested
- which authentication method you used
- the source environment that sent the request
- the source IP you authorized, if using IP whitelisting
- the username used, if using username and password authentication
- whether the failure occurs in cURL, the application, or both
- which endpoints or websites were tested
- whether the issue occurs all the time or only occasionally
- whether the dashboard test showed the proxy online
This makes support much faster because it narrows the failure boundary immediately.
Recommended Next Step
Continue to the section that best matches your workflow.
If your workload is code-driven, go to Language Integrations.
If your workload is browser-based and manual, go to Platform and Browser Setup.
If your workload is browser-based and automated, go to Browser Automation.
If you are still diagnosing a failure, go to Operations and Troubleshooting.