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Hardware-Level Query Performance

A2S (Source Engine) queries are the fundamental packets utilized by Steam and in-game browsers to retrieve real-time server information, such as player counts, current maps, and server names. While essential for visibility, these queries can be exploited by malicious actors to flood your server with thousands of requests, overwhelming your CPU and causing legitimate players to see your server as “Timed Out.” Cosmicguard’s A2S Caching technology solves this by answering these queries at the network edge, ensuring your server remains visible and responsive under even the most intense query-based attacks.

Difficulty

Intermediate

Time

5 Minutes

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Technical Mechanics of Edge-Querying

When A2S Caching is active, the relationship between the player’s client and your game server changes fundamentally to prioritize performance.
1

Status Learning

The Cosmicguard firewall periodically communicates with your game server to “learn” its current status (Active Players, Maximum Slots, Map Name, and Version).
2

Edge Storage

This metadata is stored in a high-speed hardware cache located directly within our global scrubbing centers.
3

Autonomous Response

When a player or a browser bot sends an A2S_INFO request, the firewall answers the query directly from its local cache.
4

CPU Preservation

Because the query never reaches your server, your CPU resources are preserved entirely for processing core game logic and player movements.

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Operational Benefits

Implementing A2S Caching provides several strategic advantages for community owners.
High player-count servers (such as 200+ slot Rust servers) generate massive query traffic naturally. By offloading these requests to the firewall, you eliminate the micro-stutters often associated with the game engine attempting to process thousands of info requests while simultaneously managing physics.

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Activation & Support

A2S Caching is automatically integrated into specific Cosmicguard Protection Profiles designed for the Valve ecosystem. To activate it, simply apply the profile that matches your game (e.g., Rust, CS2, TF2, or GMod) within the IP Addresses tab.
The cache refreshes every few seconds to ensure that your player count and map information remain accurate. This small delay is imperceptible to users but provides a massive security shield for your infrastructure.

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Supported Protocol Requirement

A2S Caching is exclusively compatible with games using the standard Valve Source Engine query protocol. If your game uses a proprietary or custom query system (such as certain Minecraft query plugins), this specific hardware caching layer may not be applicable.

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Need Extra Help?

If you encounter any issues, our support team is ready to assist:

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Last Updated: January 2026 | Cosmicguard: Advanced hardware caching.