DDoS security
Everything you need to know about Distributed Denial of Service (DDoS)
Learn about DDoS
What is DDoS?
Distributed Denial of Service (DDoS) is malicious traffic whose aim is to deny access or degrade or stop connectivity for individual users, internet hosts, and internet network infrastructure by overwhelming generating overwhelming bandwidth or service requests. So, DDoS has two “shapes”: high bandwidth volume (expressed in Gbps or Tbps) and high packet rate (expressed in millions of packets per second, Mpps).
Malicious players have been exploiting the IP protocol and its inherent system vulnerabilities for over two decades to launch DDoS attacks on their targets, including network hosts and systems. Over the years, protocols such as BGP and the Domain Name System (DNS) have gained additional security features to enhance their robustness. Additionally, industry-wide initiatives utilizing best practices have been implemented to mitigate DDoS traffic (BPM-23).
However, there are still many vulnerable hosts and systems on the internet, as well as a growing “army” of insecure IoT devices and systems that can be exploited to generate more advanced DDoS attacks.
What are the different types of DDoS?
Broadly, all DDoS traffic can be categorized into:
- Amplification and reflection DDoS
- Flooding DDoS traffic (using IP address spoofing or IP header modification, IPHM)
- Application-layer DDoS.
For a quick introduction to these, check out our Nokia TechTalks in 10 – DDoS security video playlist.
New DDoS reality – what are the dangers?
Over the last couple of years, DDoS attacks have grown significantly in terms of peak values (expressed in Tb/s or Tbps), the absolute volume of traffic (in bytes or TB), sophistication and frequency.
Today’s DDoS dangers are the result of the increased number of insecure internet systems and hosts, as well as a rapidly growing number of insecure IoT devices with ubiquitous access to gigabit- and multi-gigabit broadband connectivity.
DDoS threats have been additionally fueled by increased attack sophistication (e.g., multiple attack vectors, multiple targets, using shorter attacks, and varying tactics quickly during DDoS campaigns.
Additionally, we are seeing an increase in automated and AI-driven attacks. In our 2024 Nokia Threat Intelligence Report, we discussed how the number and frequency of DDoS attacks have increased from one or two per day to well over 100 per day in many networks. Many operators, even those in smaller countries, have observed a significant increase in daily DDoS activity aimed at their network and customers.
In 2024 and 2025, we also observed a rise in the use of residential proxies to generate hyper-volumetric, multi-terabit DDoS attacks, as well as the exploitation of DDoS as a smokescreen to conceal other cybercriminal activities.
- What is DDoS?
- What are the different types of DDoS?
- What are the dangers?
- What is the impact on service provider networks?
- The rise of botnets and hypervolumetric, multi-terabit DDoS
- Why is a new approach to DDoS security needed?
- Using AI is becoming the cornerstone of next-generation, adaptive DDoS defense
- Leveraging the network as a sensor and enforcer
- Meet the Nokia DDoS security solution
- Related products and solutions
- Learn more

Product
Deepfield Defender

Product
7750 Defender Mitigation System
What is the impact on service provider networks?
Large-scale DDoS attacks can be devastating for network routers and infrastructure, disrupting connectivity and service availability for communication service providers (CSPs), cloud providers, enterprises and consumers. They can lead to losses ranging from thousands to millions of dollars.
DDoS attacks target a range of entities, including individual users, networks belonging to service providers, cloud builders, and large digital enterprises.
While most DDoS attacks are a nuisance (e.g., attacks among gamers, as reported by some operators), high-bandwidth and high packet-intensity, hyper-volumetric attacks (now even referred to as exa-scale attacks) are cause for concern. Modern DDoS attacks can disrupt connectivity and service availability, resulting in financial, legal and reputational damage that cost hundreds of thousands or even millions of dollars in production and operational losses.
Service providers are affected in several ways:
- Their residential customers experience a degraded quality of experience (gaming, streaming, broadband connectivity)
- Their enterprise customers have degraded service or no service at all, affecting their Service Level Agreements (SLAs)
- With more security regulations (such as NIS2 in the EU) being brought up worldwide, there is an increased regulatory obligation to minimize the effects on critical infrastructure and services and provide timely reports to regulators
- Attacks that are launched from network users within the network on outside targets (outbound DDoS) may affect overall network connectivity (e.g., DDoS causing upstream congestion on the submarine or satellite connections) or may even be criminally liable
The rise of botnets and hypervolumetric, multi-terabit DDoS
At the core of most DDoS attacks today are botnets. A botnet is a collection of compromised sets of individual devices – your home computers, routers, IP cameras, digital video recorders (DVRs) and other Internet of Things (IoT) devices - even parking meters, that are commonly called bots or zombies because they have been hijacked or taken over by hackers. The infected machines are typically triggered and controlled from a command and control (C&C) center, which is often a compromised server or a remote computer used by cybercriminals.
Botnet DDoS traffic has exhibited significant growth over the last several years. In marked contrast to the pre-IoT era, most of the largest DDoS attacks today exclusively leverage large-scale botnets.
Attacks today are no longer coming from “outside” but are also generated from within service provider networks – by malicious users or hijacked devices. Botnet DDoS detection is also very challenging, as traditional approaches such as thresholds or baselines are no longer effective.
The Mirai malware family has given rise to a new wave of hyper-volumetric IoT botnets (notably Eleven11bot (Rapper Bot), Aisuru, and several other variants) that weaponize tens of thousands of DVRs, NVRs, IP cameras, and home/business gateways. These devices, often running outdated system kernels with hard-coded credentials, are scattered across a very fragment supply chain, with hard-to-find responsibility.
Once enrolled in a botnet, most devices remain there permanently and can be triggered to launch DDoS attacks without warning. In 2025, DDoS floods in the 3- to 6 Tbps range, with up to two to four gigapackets per second, have become common. A March 2025 campaign driven by Eleven11bot (Rapper Bot) resulted in multiple multi-hour outages for a leading global social media platform.
Botnets are also responsible for the vast majority of today's Layer 7 attacks, which mostly originate from botnets over the Transmission Control Protocol (TCP). An anti-DDoS solution that can effectively and timely detect and mitigate botnet DDoS attacks will also be instrumental in removing a large portion of application-layer attacks, as described in this blog post about layered protection.
Residential proxies – what are they?
Residential proxies are networks that conceal end users’ IP addresses and are marketed as tools for enhanced privacy, similar to virtual private networks (VPNs). Unlike VPNs, which typically use static, data-center-based IP addresses and are predominantly used for privacy reasons, residential proxies offer constantly rotating IP addresses derived from consumer internet services. This rotation helps attackers bypass conventional security measures.
Initially, residential proxies facilitated minor fraud activities, including sneaker scalping, ticket resales, and price scraping. Recently, however, their use has escalated significantly, especially as major AI companies have begun leveraging them to bypass data access restrictions on platforms such as Reddit, Wikipedia, and YouTube for large-scale web crawling and data scraping.
In 2024 and 2025, residential proxy networks have shifted from a fringe tool for fraud to a mainstream infrastructure risk. Today, residential proxy networks comprise millions of IPv4 endpoints that covertly retransmit traffic from ordinary consumer devices.
Two forces are accelerating the threat. First is bandwidth. Symmetric FTTH roll-outs mean home routers can now sustain gigabit- and even multi-gigabit uplinks. Second is industrial-scale AI scraping.
For a quick overview of residential proxy DDoS attacks and dangers brought by them, check out our video “Enemy Within: A Year of Residential Proxy Attacks.”
Algorithmic and AI-driven DDoS
Attackers have always been automating parts of their DDoS campaigns. Still, in 2025, the automation of DDoS attacks has become more dangerous as AI tools are increasingly used to launch, monitor and adjust DDoS attacks.
In a very short period, a complex DDoS attack can “shape-shift”; one minute it may be a narrow TCP carpet-bombing attack, shifting to a UDP flood seconds later, then to a DNS attack, and finally to a high-rate SYN flood.
AI-driven attacks exhibit not only greater sophistication and rapid vector changes, but it seems that attackers have discovered new means to track the effectiveness of their attacks and adapt accordingly. For defenders, new challenges with detection and mitigation and posed by sophisticated algorithmic orchestration of DDoS attacks; attackers are now able to monitor defenders’ thresholds and alert cadence, as well as their defense tactics, and then shuffle techniques and tactics, sources, destinations or payloads.
Why is a new approach to DDoS security needed?
The evidence is clear and compelling: the Distributed Denial-of-Service threat has fundamentally and irrevocably changed; DDoS has morphed from a manageable, external problem of server misconfiguration into an internal, asymmetric, and often politically motivated crisis. The rise of the residential proxy botnets—the "enemy within"—has rendered traditional, perimeter-based, human-in-the-loop defenses obsolete. The hit-and-run tactics of micro-burst attacks operate at a speed and scale that humans cannot match, and the risk of collateral damage from imprecise mitigation is unacceptably high.
Legacy approaches that rely on hardware-based probes or Deep Packet Inspection (DPI) are no longer effective – they cannot scale beyond a very limited set of customers and systems. With growing traffic volumes, they also cannot scale cost-efficiently.
The next-generation DDoS security solution requires a new security architecture that accommodates this new reality. It must be built on a foundation of high-speed, fully automated, AI-driven defense.
The DDoS defense must be intelligent enough to understand the context of traffic, not just its volume; it must be precise enough to surgically remove threats without harming legitimate users; and it must be adaptive enough to learn from every encounter in an escalating arms race with an equally sophisticated adversary.
Furthermore, this intelligence must be deeply integrated into the network fabric itself, transforming routers from passive forwarders into active enforcers.
Using AI is becoming the cornerstone of next-generation, adaptive DDoS defense
A next-generation DDoS defense must be built around three key AI pillars.
The first component is big data-based, AI-driven traffic anomaly detection.
This represents a significant departure from the legacy approach, which utilizes static threshold-based detection methods that are notoriously prone to false positives, often confusing legitimate network traffic events, such as the release of a viral video or a new game, with an attack. The AI-driven approach, by contrast, ingests and correlates vast streams of network data in real-time. It analyzes both the volume of network traffic and its context. This includes enriching the traffic data with a massive repository of internet intelligence, such as identifying the specific type of device behind a source IP address, its known vulnerabilities, historical behavior, and relationship to known botnet clusters. This deep contextual analysis is the key to dramatically reducing false positives and achieving the high-confidence detection necessary to trigger an automated response.
The second component is AI-based auto-mitigation. Once an attack is detected with high confidence, an AI model generates and deploys an optimized, automated response. This is not a one-size-fits-all countermeasure. The AI considers a multitude of factors to craft a surgical response tailored to the specific attack. These factors include the mix of attack vectors being used (e.g., TCP SYN flood, UDP flood, application-layer attack), the precise location and capabilities of available mitigation appliances across the network (including routers), and the unique fingerprint or characteristics of the botnet cluster involved. The goal is to apply the most effective countermeasure at the most efficient point in the network, neutralizing the threat with minimal collateral damage.
The third and most critical component is continuous, adaptive learning. The solution must be designed as a closed-loop system, creating a continuous feedback cycle. It constantly measures the effectiveness of its own mitigation actions against real-world attacks. This performance data is fed back into the system to train and refine the AI models. The system learns from every attack it encounters, becoming progressively better at identifying new threats, optimizing its countermeasures, and fine-tuning the delicate balance between minimizing false negatives (missed attacks) and false positives (blocking legitimate traffic). This adaptive capability is essential for long-term success.
Leveraging the network as a sensor and enforcer
In the next-generation defense architecture, the network itself must be transformed into an active sensor grid and enforcement fabric. This strategy leverages advancements in network hardware and programmability, turning existing infrastructure into a powerful, distributed DDoS mitigation platform.
Modern network silicon has evolved to the point where it can perform sophisticated packet filtering at massive scale and speed. These routers are capable of enforcing hundreds of thousands of Access Control List (ACL) rules on a single device, at line rate, without any performance degradation. This means that precise, granular filtering rules can be applied to traffic as it enters the network, far more efficiently than diverting it to a centralized, off-path scrubbing center.
The key that unlocks this capability is the programmability of modern network devices. Using standardized, modern APIs like NETCONF, the centralized AI mitigation engine can dynamically program these routers in real-time. When an attack is detected, the AI engine can generate surgical blocking rules and push them directly to the network edge routers closest to the source of the attack. This enables a highly distributed and efficient defense, stopping malicious traffic as close to its source as possible.
This new architectural approach carries a powerful economic argument. Research indicates that over 95% of all DDoS attacks can be effectively mitigated directly on existing, modern routers. This allows service providers to leverage the massive investments in their existing network infrastructure, rather than requiring enormous new capital investment for a separate network layer of specialized, single-purpose DDoS security scrubbing appliances. The network routers, which are already deployed for packet forwarding, become a dual-use asset, serving as the first and most effective line of defense against most DDoS threats.
Meet the Nokia DDoS security solution
Nokia’s approach to DDoS security combines big data analytics and AI-driven intelligence of Nokia Deepfield Defender, with the programmability of the advanced, latest generations of IP network routers (such as FP4/FP5/FPcx-based Nokia Service Routers or Service Interconnect Routers) and next-generation DDoS mitigation appliances such as 7750 Defender Mitigation System, to deliver a next-generation DDoS detection and mitigation solution with significant benefits over legacy (appliance-based or DPI-based) approaches: better scalability, improved detection (with lower false positives), more agile and granular, network-based mitigation, and all this with much-improved cost efficiency.
Learn more about Nokia's approach to DDoS security in this video.
Nokia Threat Intelligence Report 2024
Discover emerging cybersecurity trends and technologies and their impact on the telecom industry.

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