Anti-DDoS guidePublished on 2026-05-09Reading time: 13 min
Why firewalls fail against DDoS attacks
Classic firewalls protect policies and sessions, but DDoS attacks target capacity, packet rate and state exhaustion before the application can respond.
Firewalls are not scrubbing centers
Classic firewalls protect policies and sessions, but DDoS attacks target capacity, packet rate and state exhaustion before the application can respond.
State becomes a weakness
Classic firewalls protect policies and sessions, but DDoS attacks target capacity, packet rate and state exhaustion before the application can respond.
Filtering must happen upstream
Classic firewalls protect policies and sessions, but DDoS attacks target capacity, packet rate and state exhaustion before the application can respond.
A firewall is essential for access control, segmentation and policy enforcement, but it is not automatically a DDoS mitigation platform. Many firewalls are designed to inspect sessions, not to absorb millions of unwanted packets per second or hundreds of gigabits before the protected network.
This distinction matters for companies that believe buying a bigger firewall is enough. During DDoS, the bottleneck may be the uplink, state table, CPU path, logging pipeline or SYN/UDP processing long before application security rules become useful.
Protection model
Where Peeryx fits
Classic firewalls protect policies and sessions, but DDoS attacks target capacity, packet rate and state exhaustion before the application can respond.
DDoS targets availability. A stateful firewall often receives the flood after bandwidth and packet rate already reached the customer edge. At that point the device must process packets the upstream network should have reduced.
If the firewall tracks sessions, counters, logs or application rules for every packet, the attacker can turn those features into load. Security depth becomes a performance surface.
Why this hurts sales and operations
When the firewall collapses, every protected service behind it can fail together: web portals, APIs, VPS, game servers and management tools. The outage looks larger than the original target.
For hosting and gaming, this is especially risky because one attacked customer can degrade shared infrastructure and create support pressure across the platform.
The practical objective is to protect revenue, support teams and brand trust, not just to make a graph look clean. A mitigation article must therefore connect technical symptoms to business continuity: what stays online, what is degraded and how quickly the client can recover normal routing.
What works better
Keep the firewall for policy, but put DDoS reduction before it. This can be protected transit, scrubbing, FlowSpec/ACL assistance, tunnel delivery or a dedicated filtering layer.
The goal is to make the firewall see traffic close to normal production conditions, not raw attack volume. Then it can do what it is good at: segmentation and access rules.
Before choosing a model, define the protected asset precisely: a full ASN, a single prefix, one VPS, one dedicated server or one game endpoint. The best solution changes when the bottleneck is upstream bandwidth, packet rate, firewall state or protocol behavior.
Protected IP transit
Use BGP, tunnel or cross-connect delivery when the protected perimeter must sit before your server.
DDoS protected dedicated server
A better fit when you need compute close to the filtering stack.
Gaming reverse proxy
For selected game services where protocol-aware delivery matters.
How Peeryx uses firewalls safely
Peeryx does not treat the customer firewall as the first absorber of the attack. The attack should be reduced upstream, then clean traffic delivered to the network, server or proxy endpoint.
This lets customers keep their existing firewall strategy while adding a mitigation layer that understands volumetric pressure, PPS and routing delivery.
This is also why Peeryx separates delivery models instead of forcing every customer into the same product. Transit customers need routing freedom, while gaming and server customers often need a more operationally simple path.
An enterprise puts a 40 Gbps firewall in front of applications, but receives 12 Mpps of small TCP packets. Bandwidth is not the only issue; packet decisions and state handling become unstable.
With protected transit, the noisy pattern is removed before the handoff. The firewall still enforces policy, but no longer carries the entire DDoS burden.
Common mistakes
Sizing only by Gbps is a common error. PPS and state behavior are often the real collapse point.
Another mistake is enabling deep inspection and verbose logging during an attack. That can amplify the workload the attacker wants to create.
Why choose Peeryx
The right choice is not only advertised capacity: it is the filtering point, precision, clean handoff and the ability to keep customers online during the attack.
Filtering before saturation
Peeryx prioritizes upstream reduction so the customer server, VPS or firewall is not the first failure point.
Adapted delivery
Protected transit, tunnel, cross-connect, dedicated server or gaming proxy according to the real need.
Technical reading
Gbps, PPS, protocols and service behavior are read together to avoid broad collateral filtering.
No. Medium-size attacks can be critical when PPS, state or protocol behavior hits the wrong bottleneck.
Can this protect gaming services?
Yes, when filtering keeps legitimate real-time traffic instead of blocking the whole protocol.
Do I need BGP?
BGP is useful for prefixes and transit, but tunnel, protected server or proxy delivery may fit other cases.
What should be checked first?
Capacity, PPS, routing path, service protocol and how clean traffic returns to production.
Conclusion
Classic firewalls protect policies and sessions, but DDoS attacks target capacity, packet rate and state exhaustion before the application can respond.
The right choice is not only advertised capacity: it is the filtering point, precision, clean handoff and the ability to keep customers online during the attack.
Resources
Related reading
To go deeper, here are other useful pages and articles.
