> ## Documentation Index
> Fetch the complete documentation index at: https://docs.apinizer.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Authentication Failures

> You can detect authentication failures in Apinizer, resolve token validation issues, manage Identity Provider connections, and configure authentication policies.

## Problem Symptoms

<Warning>
  Authentication failures usually manifest themselves with the following symptoms:
</Warning>

* `401 Unauthorized` errors
* `403 Forbidden` errors
* Token validation errors
* User login issues
* API key validation errors

## Problem Causes

Authentication failures can usually be caused by the following factors:

* **Invalid Credentials**: Wrong username, password, or token
* **Token Expired**: Token's expiration time expiring
* **Wrong Token Format**: Token format not being in expected format
* **Identity Provider Issues**: LDAP, Database, or Security Manager issues
* **Policy Configuration Errors**: Authentication policy being incorrectly configured
* **Network Issues**: Identity provider access issues
* **Certificate Issues**: mTLS or JWT certificate issues

## Detection Methods

### 1. Log Analysis

<Steps>
  <Step title="Check Log Files">
    Search for authentication errors in log files:

    ```bash theme={null}
    kubectl logs <pod-name> | grep -i "authentication"
    kubectl logs <pod-name> | grep -i "401"
    kubectl logs <pod-name> | grep -i "403"
    kubectl logs <pod-name> | grep -i "unauthorized"
    ```
  </Step>
</Steps>

### 2. Analytics Dashboard

<Info>
  Monitor authentication errors in Analytics dashboard:
</Info>

* Authentication failure rate
* Error type distribution
* Endpoint-based error analysis
* User-based error analysis

### 3. Policy Test

Test the authentication policy:

* Test the policy using test endpoint
* Test with different credentials
* Check policy logs

## Solution Recommendations

### 1. Checking Credentials

Check credentials:

* Are username and password correct?
* Is token valid and not expired?
* Is token format correct?
* Is API key valid?

### 2. Token Management

Check token management:

* Check token expiration times
* Check token refresh mechanism
* Verify token format
* Check token signature

### 3. Checking Identity Provider Connection

Check Identity provider connection:

**LDAP:**

* Is LDAP server accessible?
* Are Bind DN and password correct?
* Are Base DN and search filter correct?

**Database:**

* Is database connection working?
* Are user table and columns correct?
* Is password hash algorithm correct?

**Security Manager:**

* Is user defined in Security Manager?
* Is user active?
* Are roles correctly assigned?

### 4. Checking Authentication Policy Configuration

Check authentication policy configuration:

* Is correct Identity Provider selected?
* Are username and password variables correct?
* Are token location and prefix settings correct?
* Are conditions correctly configured?

### 5. Certificate Check (mTLS/JWT)

Check certificates:

* Is CA certificate correctly loaded?
* Is client certificate valid?
* Have certificate expiration dates been checked?
* Is Issuer ACL correctly configured?

### 6. Network and Firewall Check

Check network and firewall rules:

* Do pods have access to Identity Provider?
* Are ports open?
* Are network policies blocking connection?

## Common Error Scenarios and Solutions

### Scenario 1: Token Expired

<Warning>
  **Symptoms:**

  * `401 Unauthorized` error
  * "Token expired" message
</Warning>

**Solution:**

* Refresh token
* Increase token expiration time
* Use token refresh mechanism

### Scenario 2: Wrong Token Format

<Warning>
  **Symptoms:**

  * `401 Unauthorized` error
  * "Invalid token format" message
</Warning>

**Solution:**

* Check token format
* Check token prefix (Bearer, Basic, etc.)
* Check token location (Header, Query Parameter, etc.)

### Scenario 3: Identity Provider Connection Error

<Warning>
  **Symptoms:**

  * `500 Internal Server Error`
  * "Connection refused" or "Timeout" message
</Warning>

**Solution:**

* Check Identity Provider accessibility
* Check network connection
* Check connection pool settings

### Scenario 4: User Not Found

<Warning>
  **Symptoms:**

  * `401 Unauthorized` error
  * "User not found" message
</Warning>

**Solution:**

* Check that user is defined in Identity Provider
* Check user search filter
* Check username format

## Preventive Measures

### 1. Monitoring and Alerting

* Monitor authentication error rates
* Perform anomaly detection
* Set up alerts

### 2. Testing and Validation

* Perform regular authentication tests
* Test different scenarios
* Include authentication in load tests

### 3. Documentation

* Document authentication configuration
* Prepare troubleshooting guides
* Share best practices

## Related Resources

* [Authentication Errors](/en/operations/common-problems-solutions/authentication-failures)
* [Plain Text Authentication](/en/develop/policies/plain-text-authentication)
* [OAuth2 Authentication](/en/develop/policies/oauth2)
* [mTLS Authentication](/en/develop/policies/mtls-authentication)