Vai al contenuto
PEERYXNETWORK

Attacchi DDoS: sintomi, vettori e filtraggio.

Un servizio irraggiungibile non identifica il vettore di attacco. Verifica direzione del traffico, destinazioni colpite e punto in cui i pacchetti smettono di passare. Confronta poi le osservazioni con il protocollo.

Le guide trattano flood di rete, riflessione, connessioni e limiti del filtraggio. Un campione di pacchetti o un bitrate elevato non dimostra da solo la causa di un guasto: correla stato del servizio e routing.

Ordine di lettura consigliato

  1. Definire il sintomo

    Registra inizio del problema, destinazioni colpite e aumento di byte, pacchetti o tentativi di connessione. Mantieni coerenti intervalli di misura e convenzioni dei contatori.

  2. Identificare il comportamento del protocollo

    Nella riflessione, separa le richieste al riflettore dalle risposte ricevute dalla vittima. DNS, NTP e Memcached hanno messaggi, controlli e condizioni di esposizione diversi.

  3. Verificare il traffico legittimo prima di irrigidire le regole

    Confronta la condizione di filtraggio con traffico normale, uso del NAT e percorso di ritorno. I controlli TCP con stato richiedono il percorso previsto; una regola severa non è necessariamente corretta.

Guide di questa sezione

19 guide

Alcune guide sono disponibili solo in inglese. La lingua è indicata prima dell’apertura.

19 / 19 guide

Why a firewall alone may not stop a DDoS attack

Separate link saturation, packet processing, connection state and application load to find where a firewall needs upstream or specialist DDoS protection.

Attacchi DDoS5 min di letturaAggiornato In inglese

High-PPS DDoS mitigation: measure the packet path

Find packet-rate bottlenecks with explicit frame sizes, queue and worker measurements, legitimate-traffic tests and a capacity result you can reproduce.

Attacchi DDoS5 min di letturaAggiornato In inglese

DDoS vs DoS: difference, impact and protection choices

Understand the difference between DoS and DDoS attacks, why it changes the mitigation design and when to choose protected IP transit, a protected server, VPS or gaming proxy.

Attacchi DDoS3 min di letturaAggiornato In inglese

Memcached DDoS: diagnosis and mitigation

Diagnose reflected Memcached replies, distinguish victim-side filtering from securing a cache, and preserve legitimate traffic when choosing where to mitigate.

Attacchi DDoS5 min di letturaAggiornato In inglese

NTP amplification: diagnosis and filtering

Distinguish legitimate time synchronization from reflected NTP traffic, restrict exposed control queries and validate mitigation without breaking your clocks.

Attacchi DDoS5 min di letturaAggiornato In inglese

ACK flood protection: mitigate TCP DDoS attacks without blocking real sessions

An ACK flood targets the part of TCP that should normally look legitimate: packets that appear to belong to established connections. The problem is not only bandwidth. High packet rate, spoofed ACKs and asymmetric paths can exhaust firewalls, load balancers, routers or servers before the application understands what is happening. Good mitigation must reduce the flood early while preserving real sessions that already exist.

Attacchi DDoS5 min di letturaAggiornato In inglese

DDoS amplification attack explained: why small requests can become massive floods

A DDoS amplification attack uses third-party services to turn small spoofed requests into much larger responses sent to the victim. The target does not only receive traffic from the attacker. It receives reflected traffic from many legitimate servers on the Internet, often using UDP-based protocols. Understanding amplification is essential before choosing protected IP transit, a scrubbing model or a gaming proxy, because the failure point is usually upstream capacity rather than the application itself.

Attacchi DDoS3 min di letturaAggiornato In inglese

DNS amplification DDoS mitigation: protect exposed infrastructure without blocking legitimate DNS

DNS amplification is one of the most common UDP reflection patterns because DNS is widely available, response sizes can be larger than requests and spoofed traffic can be directed at a victim. The mitigation challenge is precise: blocking all UDP/53 may stop a graph, but it can also break DNS-dependent services. A serious design separates open resolver abuse, reflected floods and legitimate DNS traffic before the attack reaches the customer edge.

Attacchi DDoS3 min di letturaAggiornato In inglese

SYN flood protection: mitigate TCP DDoS attacks without blocking real connections

A SYN flood is not only about sending many packets. It abuses the TCP opening phase to create pressure on connection queues, stateful firewalls, load balancers and exposed servers. Effective protection must filter early, avoid state exhaustion and keep legitimate users able to establish sessions.

Attacchi DDoS7 min di letturaAggiornato In inglese

UDP flood mitigation: stop a UDP DDoS without breaking legitimate traffic

A UDP flood is not just “a lot of UDP packets”. Depending on the service, it can saturate a link, exhaust a firewall, trigger useless responses or disrupt a real-time protocol such as gaming, VoIP, DNS, VPN or a UDP-based application. Good mitigation is not about blocking UDP everywhere. It is about separating obvious noise from useful traffic, protecting upstream capacity and delivering clean traffic with low latency.

Attacchi DDoS7 min di letturaAggiornato In inglese

Volumetric vs application-layer DDoS: differences, risks and the right mitigation model

A volumetric DDoS attack and an application-layer DDoS attack do not break a service in the same way. The first mainly tries to saturate network capacity, ports, packet rate or upstream paths. The second targets service logic: HTTP, APIs, authentication, game proxies or expensive requests. Understanding the difference helps choose a mitigation design that actually works instead of relying on a generic Anti-DDoS promise.

Attacchi DDoS6 min di letturaAggiornato In inglese

L3, L4, L7 protection: the real differences in Anti-DDoS

L3, L4 and L7 are often used as sales labels, but they do not protect the same part of the traffic path. This guide explains the real differences between network, transport and application filtering, and how to choose a coherent Anti-DDoS design with protected IP transit, tunnels, reverse proxy or router VM.

Attacchi DDoS5 min di letturaAggiornato In inglese

Adattare la risposta al limite reale.

Se l’accesso è saturo, filtrare a valle non recupera la capacità perduta. Confronta consegna tramite rete protetta e filtraggio locale, poi verifica velocità in pacchetti e in bit.

Documentazione, strumenti e servizi