Investigating IP Block Issues in DirectAdmin Hosting with Root Access Print

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🔍 Investigating IP Block Issues in DirectAdmin Hosting with Root Access

Stay in full control of your hosting environment by learning how to trace, diagnose, and resolve IP block list issues in DirectAdmin-based VPS or dedicated servers. This in-depth guide is designed for server administrators with root access.


🧰 Prerequisites

  • ✅ Root SSH access to your server

  • ✅ DirectAdmin installed (CentOS, AlmaLinux, etc.)

  • ✅ CSF + LFD Firewall active

  • ✅ ModSecurity (Imunify360 or Core Ruleset)

  • ✅ Familiarity with basic Linux commands


1️⃣ Check IP in CSF Firewall

csf -g <IP_ADDRESS>

🔎 This command reveals:

  • Whether the IP is in csf.deny

  • Temporary block entries

  • Matches in IPTables or IPSET

Example: csf -g 178.153.59.55


2️⃣ Check Temporary Blocks via LFD Logs

grep "178.153.59.55" /var/log/lfd.log

📌 Look for:

  • Block reason (e.g., failed logins, port scan)

  • CSF tempban triggers


3️⃣ Inspect ModSecurity Logs (WAF Detection)

🔐 For Default ModSecurity

grep "<IP>" /var/log/httpd/modsec_audit.log

🔐 With Imunify360 WAF

grep "<IP>" /var/log/httpd/modsec_audit.log*

📌 Details to check:

  • Rule ID (e.g., 77391380)

  • Error: SQLi using libinjection with fingerprint 'X'

  • Rule file (e.g., 016_i360_monitor.conf)


4️⃣ Analyze Apache Logs (Access & Errors)

grep "<IP>" /var/log/httpd/access_log

grep "<IP>" /var/log/httpd/error_log

💡 Identify:

  • 403, 406, 500 errors

  • User agent anomalies

  • Potential redirect loops


5️⃣ Audit Email Login Failures

grep "<IP>" /var/log/maillog | grep login

📨 This is useful if IP blocks originate from email client authentication failures.


6️⃣ Review DirectAdmin Brute Force Logs

grep "<IP>" /var/log/secure

grep "<IP>" /var/log/messages

🚫 Find out if login attempts to DirectAdmin, FTP, SSH, or mail services triggered blocks.


7️⃣ Whitelisting the IP (If Safe)

csf -a <IP> "Whitelisted: Developer or Trusted User"

🔓 To remove a deny entry:

csf -dr <IP>

8️⃣ Exclude WAF Rule for False Positives

If a known false-positive WAF rule (e.g., 77391380) is affecting a safe IP:

✏ Add to whitelist config:

SecRule REMOTE_ADDR "@ipMatch 178.153.59.55" "id:100001,phase:1,nolog,pass,ctl:ruleRemoveById=77391380"

✅ Then restart Apache:

systemctl restart httpd

9️⃣ Test & Confirm

🎯 After changes:

  • Clear browser cache or try incognito mode

  • Use curl, ping, or browser to verify access


🔒 Proactive Tips to Prevent Future IP Blocks

  • 🛡 Tune CSF thresholds for login failures

  • 🔁 Monitor WAF false positives and update rules

  • 📧 Educate clients on email security best practices

  • 🚀 Avoid overly aggressive security rule sets


🧾 Useful Commands Summary

✅ Purpose 🧩 Command
Search IP in CSF csf -g <IP>
Whitelist IP csf -a <IP>
Remove deny entry csf -dr <IP>
Search LFD logs grep <IP> /var/log/lfd.log
ModSecurity logs grep <IP> /var/log/httpd/modsec_audit.log
Email login failures grep <IP> /var/log/maillog | grep login

📌 Conclusion

With root access and the right investigation steps, resolving IP block issues in a DirectAdmin environment becomes fast and precise. From firewall analysis to WAF exclusions, these techniques ensure a secure yet accessible hosting experience.

📘 Bookmark this guide as your go-to IP block investigation checklist!


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