OVH Anti-DDoS stops volumetric floods at L3/L4. But it cannot detect SSH brute force patterns, SQL injection in your web logs, or malware on disk. Defensia fills every gap Anti-DDoS leaves open — on VPS, dedicated, and hosted private cloud.
Secure your OVH server in 30 seconds →OVHcloud is one of the largest hosting providers in Europe, known for affordable dedicated servers and strong European data sovereignty (GDPR compliance). Their always-on Anti-DDoS VAC system is genuinely good — it scrubs volumetric L3/L4 floods before they reach your server. But DDoS protection and application security are two fundamentally different things. Anti-DDoS stops packet floods. It does nothing about SSH brute force, SQL injection, web shells, or unpatched CVEs.
sshd[4821]: Failed password for root from 185.220.101.7 port 43992 ssh2
sshd[4823]: Invalid user admin from 45.83.64.11 port 55120 ssh2
sshd[4825]: pam_unix(sshd:auth): authentication failure; rhost=103.145.13.90
sshd[4827]: Failed password for invalid user ubuntu from 92.118.39.18 port 22180
sshd[4830]: Disconnected from authenticating user root 45.83.64.11 port 38204 [preauth]
... thousands more today. Anti-DDoS does not stop these.
OVH servers are particularly popular with hosting companies and agencies running dozens or hundreds of websites on dedicated hardware. This density makes them high-value targets — a single compromised server can expose every site it hosts. Many OVH servers run Debian, which ships with no firewall frontend and no automatic security updates. OVH's network firewall is basic, with limited rules and no traffic logging. Anti-DDoS handles floods, but the 4,200+ daily SSH brute force attempts, web exploit scans, and bot traffic pass through untouched. You need an active security layer that watches, detects, and responds at the application level.
OVHcloud is a strong infrastructure provider — reliable hardware, excellent network backbone, European data sovereignty, and competitive pricing on dedicated servers. But infrastructure protection and host-level security serve different purposes. Here is what OVH provides natively and where the gaps are.
| Security layer | OVHcloud | Defensia |
|---|---|---|
| Network firewall | Basic firewall (limited rules) | iptables/ipset (automatic, unlimited) |
| DDoS protection | Anti-DDoS VAC (L3/L4, always-on) | L7 via WAF log analysis |
| Firewall logs / traffic visibility | ✗ | Full event log + dashboard |
| SSH brute force detection | ✗ | 15 patterns, auto-ban |
| Web Application Firewall (WAF) | ✗ | 15+ OWASP types from nginx/Apache logs |
| Malware scanning | ✗ | 64K+ hash signatures + 684 patterns |
| CVE / vulnerability scanning | ✗ | NVD + EPSS + CISA KEV |
| Server monitoring | Basic (hardware only) | Security events + attacks + posture score |
| Geoblocking | ✗ | 200+ countries at firewall level |
| Bot management | ✗ | 70+ fingerprints, per-policy |
| Real-time attack dashboard | ✗ | ✓ |
| Private networking (vRack) | ✓ | ✗ |
| IPMI/KVM console | ✓ | ✗ |
| European data sovereignty | ✓ | ✗ |
Credit where it is due: OVH Anti-DDoS (VAC) is one of the best included DDoS protections in the industry — always-on, automatic, with up to 1.3 Tbps of scrubbing capacity. OVH also provides vRack (private networking), IPMI/KVM access for dedicated servers, automatic backups, and full GDPR-compliant European data sovereignty. Their data centers in France, Germany, UK, Canada, US, Singapore, and Australia offer strong geographic coverage. Defensia adds the host-level security layer — the part OVH leaves to you.
One command. Works on every OVH server — VPS, dedicated (Eco, Advance, Scale, Game), and Hosted Private Cloud. Supports Ubuntu, Debian, Rocky Linux, AlmaLinux, CentOS, and Fedora. No packages to install, no dependencies, no configuration files. The agent auto-detects your operating system, log paths, and running services.
# What happens on your OVH server:
1. Downloads the Go binary (~15MB) for your architecture (amd64 or arm64)
2. Installs to /usr/local/bin/defensia-agent
3. Creates a systemd service unit
4. Auto-detects SSH log path (/var/log/auth.log on Ubuntu/Debian, journald on Rocky/Alma)
5. Auto-detects nginx/Apache access logs (including cPanel domlogs if present)
6. Starts protecting immediately — no config files to edit
Defensia works alongside OVH Anti-DDoS and network firewall — they complement each other. Anti-DDoS scrubs volumetric floods at the network edge. The network firewall blocks unused ports. Defensia detects attacks within the traffic that passes through both layers. The agent is a single Go binary with zero dependencies, uses under 30MB of RAM, and works on OVH VPS starting from EUR 3.50/month. For OVH dedicated servers running cPanel/WHM, Defensia auto-detects Apache domlogs across all hosted domains.
Six detection engines cover every attack surface on your server — from SSH to web applications to the filesystem. Especially critical for OVH dedicated servers hosting multiple websites.
OVH dedicated servers are high-value targets — they often run for years and host multiple sites. Defensia reads /var/log/auth.log (Ubuntu/Debian) or journald (Rocky/Alma/CentOS) and detects 15 SSH attack patterns: failed passwords, invalid users, pre-auth disconnects, PAM failures, and key exchange drops. Attackers are blocked within seconds via ipset. Anti-DDoS does not inspect SSH traffic.
Deep dive into SSH protection →Anti-DDoS allows all legitimate HTTP/HTTPS traffic through — it only scrubs volumetric floods. Defensia reads nginx and Apache access logs and detects SQL injection, XSS, path traversal, RCE, SSRF, shellshock, and 10+ more OWASP attack types within that traffic. Auto-detects cPanel domlogs across all hosted domains.
See WAF detection details →OVH provides no file-level scanning. Defensia scans the filesystem with 64,000+ hash signatures and 684 dynamic patterns. Detects PHP backdoors in WordPress upload directories, obfuscated shells, cryptominers in /tmp and /dev/shm, and modified system binaries. Essential for OVH dedicated servers hosting dozens of client websites.
Matches installed packages (apt on Ubuntu/Debian, rpm on Rocky/Alma/CentOS) against the National Vulnerability Database. Each CVE is scored with EPSS exploit probability and flagged if it appears in the CISA Known Exploited Vulnerabilities catalog. Critical for OVH dedicated servers that may run for years without full OS upgrades.
70+ bot fingerprints identified from User-Agent strings and request patterns. Legitimate bots (Googlebot, Bingbot) are allowed. Vulnerability scanners, credential stuffing bots, and scrapers are blocked or logged per your policy. OVH servers hosting multiple client websites benefit from centralized bot management across all domains.
Continuous assessment of your server security: SSH configuration, firewall rules, file permissions, world-readable credentials, exposed .git directories, and weak key permissions. Scored 0-100 with A-F grade. Particularly valuable for hosting providers on OVH who need to demonstrate security posture to their clients.
OVHcloud handles infrastructure — compute, networking, storage, DDoS protection, and European data sovereignty. Defensia handles host-level security — attack detection, automated blocking, malware scanning, vulnerability management, and real-time monitoring. For OVH servers running email services, Defensia also monitors SMTP authentication attempts. Together, they form a complete stack that keeps you GDPR-compliant and protected.
Defensia is not a replacement for Anti-DDoS — it is the security layer that sits on top. Anti-DDoS scrubs volumetric network floods before they saturate your link. Defensia monitors the application-level traffic that passes through Anti-DDoS and blocks malicious actors automatically. OVH dedicated servers running cPanel, Plesk, or DirectAdmin with dozens of hosted sites benefit enormously from Defensia's centralized WAF and malware scanning across all domains.
Three steps: (1) Configure OVH network firewall to block unused ports. (2) Use SSH keys instead of password authentication. (3) Install Defensia with one command — curl -fsSL https://defensia.cloud/install.sh | sudo bash — to get SSH brute force protection, WAF, malware scanning, CVE detection, and a real-time dashboard. Anti-DDoS handles volumetric floods; Defensia handles everything at the application layer.
Yes, they solve different problems and complement each other perfectly. Anti-DDoS VAC scrubs volumetric L3/L4 floods before they reach your server — it is genuinely excellent at this. Defensia detects application-level attacks within the traffic that Anti-DDoS allows through: SSH brute force, SQL injection, malware, and CVEs. There is no conflict between them.
Yes. Defensia works on any Linux server with systemd and iptables — OVH VPS, dedicated servers (Eco, Advance, Scale, Game), and Hosted Private Cloud instances. The install is the same one-command process regardless of OVH product line.
Yes. Many OVH dedicated servers run cPanel/WHM hosting dozens of websites. Defensia auto-detects Apache domlogs across all hosted domains and monitors them for web attacks. It also scans for malware across all hosted sites, detects wp-login.php brute force attacks, and monitors SSH access to the server. One agent protects all hosted websites.
Defensia is free for 1 server — includes SSH protection, the full real-time dashboard, and bot detection. Pro costs EUR 9/server/month (EUR 7 billed annually) and adds WAF, malware scanning, CVE intelligence, geoblocking, and alerts. An OVH VPS (EUR 3.50/month) plus EUR 9 Defensia Pro is under EUR 13/month for a fully secured server.
Defensia processes security event data (IP addresses, attack patterns, timestamps) for the legitimate purpose of security monitoring. The Defensia dashboard is hosted in Europe. No personal data is shared with third parties. The tracking pixel and all endpoints are first-party only. This aligns with GDPR requirements for security processing — and complements OVH's European data sovereignty commitment.
OVHcloud Anti-DDoS VAC features (always-on L3/L4 protection, included with all services) based on official documentation: docs.ovh.com/en/dedicated/anti-ddos.
OVHcloud VPS pricing (from EUR 3.50/month) and dedicated server range based on ovhcloud.com/en/vps and ovhcloud.com/en/bare-metal as of April 2026.
OVHcloud data center locations (France, Germany, UK, Canada, US, Singapore, Australia) based on ovhcloud.com/en/about-us/global-infrastructure.
Attack frequency and time-to-first-attack metrics based on Defensia telemetry data across production servers monitored from January to April 2026.
OVHcloud network firewall limitations based on docs.ovh.com/en/dedicated/firewall-network as of April 2026.
Complete guide for all Linux distributions.
Cloud and dedicated servers in Europe.
Protect your Droplets and DOKS clusters.
Protect cPanel/WHM servers on OVH.
15 detection patterns, ipset blocking.
OWASP attack detection from server logs.
One command. Under 30 seconds. Works on every OVHcloud server — VPS, dedicated, and hosted private cloud.
No credit card required. Free for 1 server.