How We Built DayZ DDoS Mitigation: Capacity Is the Easy Part

At VYKIX, we work on VxShield while running DayZ hosting for communities facing real attacks. StalkerZ needed filter updates as payloads changed across four rounds. KarmaKrew’s campaign targeted server queries. Escape From DayZ faced repeated bursts during a wipe.

Each case gave us a specific problem to solve: which packets should reach DayZ, which queries the edge could answer, and which checks had to change as the attack developed. We built packet, query and session controls around that work.

VxShield combines Global Secure Layer (GSL) upstream mitigation with additional filtering on VYKIX’s network. This is our engineering account of the service. The retained customer charts and public protocol references do not expose the deployed filter code, complete rule history or matched player-session records.

Capacity Is the Easy Part

The 17 Tbps figure we publish is the protection network’s filtering capacity. It describes resources across that network, rather than an allowance for one game server.

Once traffic reaches a filter, the decision depends on more than its size. A copied signature can resemble a DayZ packet without belonging to a valid session. Structure, request rate and session state give the filter the context to check it.

We describe our edge packet processing as XDP/eBPF. The eBPF XDP reference explains how a program can drop, pass or redirect ingress packets; it does not verify our deployment or DayZ rules. Valid exchanges still need to pass, so test a filter change against abusive traffic and player connections.

An origin-side capture sees traffic that reaches the host. Packets dropped upstream or at an earlier XDP hook can be absent from that capture. Compare records from the filtering layer with the host logs before treating an empty capture as evidence that no attack occurred.

Part 1: The First Real Test, an Attacker Who Adapted

StalkerZ moved to VYKIX after attack-related problems at its previous host. The customer’s Discord message describes that experience; we do not have the old hosting configuration to diagnose it.

StalkerZ’s campaign lasted more than 24 hours across four rounds. An initial flood gave way to packets resembling DayZ traffic. A distributed push reached a reported 643 Gbps peak, followed by another payload change.

We updated session and payload checks as the traffic changed, with the campaign ending after the fourth round. The StalkerZ breakdown follows the four rounds and includes the original traffic charts.

That sequence required us to revisit the rules. A check that handled an earlier payload needed testing against the next one before we could treat the response as complete.

Part 2: A2S Floods and Pulse Waves, the Constant Stuff

A2S queries let a browser obtain information about a server. Abuse on that path can prevent players from finding a game that is still running. Browser replies and game joins need their own checks.

KarmaKrew faced this query pressure in early 2025. VxShield can answer supported DayZ A2S_INFO requests with cached status, reducing repeated listing work on the host and leaving game sessions on their own filtering path. The KarmaKrew case study explains the campaign and query controls.

The current cache covers supported A2S_INFO requests. A reply alone won’t tell you whether the game server is healthy, the cached status is fresh or players can play. Valve’s query documentation also allows a challenge reply to any query; a valid follow-up must include the returned challenge bytes. Check browser exchanges and joins after changing the filter.

Escape From DayZ’s wipe brought repeated bursts, with a reported peak near 980 Gbps. The charts rise and fall as the traffic returns. Keep watching through those quieter gaps: a drop after one burst does not tell you whether another will follow. The pulse wave case study includes the captures.

Part 3: Forged Packets, the One That Worried Us

A port rule or volume threshold has little to say about traffic that resembles a valid game packet. Closing the port would stop players’ connections along with the attack.

Echoes of Chernobyl moved from OVH after attacks involving forged DayZ traffic. The migration report describes forged game packets, but we no longer have the capture to show their contents.

Checking a signature was part of the response. Packet structure, request rate and session state provided the context needed to decide whether the traffic belonged to a valid exchange. The packet-spoofing case study explains those checks.

Rearmed: TCP, UDP and Game Traffic at 1.6 Tbps

We reported a 1.6 Tbps campaign against Rearmed that combined TCP, UDP and game/query abuse. Our retrospective described the server remaining available through it.

The raw traffic export and uptime logs are no longer available, so both the peak and availability result rely on that retrospective.

Where We Stand Now

These customer incidents shaped VxShield’s DayZ checks. Our work covers packet validation, supported A2S_INFO caching and session controls, with filter updates when traffic changes. We use traffic samples and drop counters to investigate the problem, then test the affected query or game path after a change.

The later 2.56 Tbps Ground Zero report offers a fuller view of a flood moving through the protection network. Pair that kind of network timeline with server and session logs when investigating your own incident. Together, they help you connect changes in traffic with failed joins or interrupted sessions.

Our DayZ DDoS protection guide explains the protection model and the questions to ask when configuring it for your server.

Common Questions

How is DayZ-specific DDoS mitigation different from generic DDoS protection?

A DayZ profile adds packet-structure, rate and session checks to network filtering. Those checks help determine whether a packet belongs to a valid exchange. Confirm which profile and controls your chosen hosting product supports.

Does more DDoS mitigation capacity mean better protection?

More capacity gives the network room to handle a larger flood. Packet processing and classification still need attention: abusive requests can strain a game or query service while bandwidth remains available.

What is the hardest DayZ DDoS attack to stop?

The difficulty depends on the traffic and the deployment. A large flood can exhaust network resources; packets imitating valid game traffic require checks that separate abusive requests from player exchanges. Test the protection against both problems.

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VYKIX plans include VxShield. Once we confirm eligibility and scope, switchers can use our best-effort migration offer; terms apply. See DayZ server hosting plans or ask VYKIX on Discord.