NTP Flood
An NTP Flood attack is a type of Distributed Denial of Service (DDoS) attack that targets the Network Time Protocol (NTP), a protocol used to synchronise clocks on devices across the internet. By overwhelming a server or network with a massive volume of NTP traffic, attackers can disrupt services and potentially take systems completely offline.
What Is an NTP Flood?
An NTP Flood is a malicious attempt to overload a target network or server by sending high volumes of NTP request packets. NTP, which is critical for keeping system clocks synchronised, can be exploited when servers are misconfigured or left exposed to the public.
Unlike many DDoS methods, an NTP Flood leverages a widely used protocol, making it easy to execute and difficult to distinguish from legitimate network traffic.
How NTP Flood Attacks Work
Attackers exploit NTP servers to generate a flood of unwanted traffic toward a target. This can happen in two ways:
- Direct flooding – attackers send an excessive number of requests to overwhelm the target server.
- Amplification – open NTP servers are used to reflect and magnify attack traffic, directing far larger volumes at the target than the attacker sends out.
This makes NTP Floods particularly dangerous, similar in some ways to a UDP Flood DDoS Attack, but with the added risk of protocol amplification.
How to Detect and Mitigate NTP Flood Attacks
Defending against NTP Flood attacks requires a mix of proactive monitoring and layered protection:
- Traffic monitoring – use network traffic analysis tools to detect unusual spikes in NTP requests.
- Rate limiting and filtering – limit request rates and block malicious IPs where possible.
- Server hardening – disable unnecessary commands on NTP servers or restrict access to trusted IP ranges.
- Deploy advanced DDoS protection – automated, real-time mitigation systems can detect and block attacks before they impact services.
Get in touch
NTP Flood attacks can cause significant downtime and operational disruption if left unmitigated. Staying prepared with robust detection and protection measures is key to keeping networks secure and services reliable.
For expert guidance on defending your organisation, speak to a DDoS specialist today.
