Solved: Apache Infinite Redirect Loop Error (AH00124) in Apache 2.4.62+
Quick Fix Summary
TL;DRImmediately disable or simplify your .htaccess rewrite rules and restart Apache to break the loop.
Apache's internal redirect limit prevents infinite loops from consuming server resources. This error occurs when rewrite rules or aliases create a circular path that never resolves to a final resource.
Diagnosis & Causes
Recovery Steps
Step 1: Isolate and Disable the Problematic Configuration
Quickly stop the loop by disabling the most likely culprit, typically .htaccess rewrite rules, to restore service.
# Rename .htaccess to disable it
sudo mv /var/www/html/.htaccess /var/www/html/.htaccess.disabled
# Restart Apache to apply changes
sudo systemctl restart apache2Step 2: Enable mod_rewrite Logging for Debugging
Turn on detailed rewrite logging to trace the exact sequence of internal redirects causing the loop.
# Add to your Apache virtual host config (e.g., /etc/apache2/sites-available/000-default.conf)
RewriteEngine On
RewriteLog "/var/log/apache2/rewrite.log"
RewriteLogLevel 9
# Test config and restart
sudo apache2ctl configtest
sudo systemctl reload apache2Step 3: Analyze the Rewrite Log and Fix the Rule
Examine the rewrite log to identify the circular pattern. A common fix is adding conditions to prevent re-processing.
# Tail the rewrite log to see the loop in real-time
sudo tail -f /var/log/apache2/rewrite.log
# Example fix: Prevent redirecting already-rewritten URLs
# In .htaccess, add a condition like:
RewriteCond %{ENV:REDIRECT_STATUS} ^$
RewriteRule ^(.*)$ https://example.com/$1 [R=301,L]Step 4: Check for Conflicting Directives in Main Config
Loops can be caused by interactions between .htaccess and main server config (httpd.conf or apache2.conf).
# Search for Alias, Redirect, or ProxyPass directives that might overlap with your .htaccess rules
grep -r "Alias\|Redirect\|ProxyPass" /etc/apache2/
# Temporarily comment out suspect directives in main config files, test, and restart.Step 5: Implement a Safe RewriteRule Pattern
Ensure your rewrite rules have proper termination conditions and avoid matching their own target.
# BAD: This can create a loop if not carefully conditioned
RewriteRule ^(.*)$ /index.php?url=$1 [L]
# BETTER: Add a condition to exclude the target file/folder
RewriteCond %{REQUEST_URI} !^/index\.php
RewriteRule ^(.*)$ /index.php?url=$1 [L,QSA]Step 6: Clean Up and Verify
Disable debug logging, re-enable your corrected configuration, and perform a final test.
# 1. Remove or comment out RewriteLog directives from main config.
# 2. Rename your corrected .htaccess file back.
sudo mv /var/www/html/.htaccess.disabled /var/www/html/.htaccess
# 3. Restart Apache and test with curl.
sudo systemctl restart apache2
curl -I http://your-domain.com/test-pageArchitect's Pro Tip
"Use `curl -L -v http://yoursite.com` to see the client-side redirect chain. If it's long, Apache is likely generating the internal loops before sending the final response."
Frequently Asked Questions
Why did this start happening after an Apache update (e.g., to 2.4.62)?
Newer Apache versions enforce stricter limits and default behaviors. Changes in mod_rewrite's merging logic for .htaccess files or default `LimitInternalRecursion` can expose previously hidden flawed rules.
Can I just increase the `LimitInternalRecursion` directive instead of fixing the rules?
No. Increasing `LimitInternalRecursion` from its default (10) is a dangerous workaround. It masks the configuration error, wastes CPU cycles, and can make your server unresponsive under load.
The error only happens with HTTPS, not HTTP. Why?
This strongly points to a misconfigured SSL redirect in your virtual host. Check for conflicting `RewriteCond %{HTTPS}` rules in both port 80 and port 443 configurations that might be bouncing requests between them.