Resource Starvation
Connection Exhaustion
A connection exhaustion attack consumes all available connection slots on a target peer. Each connection is individually legitimate — proper handshake, valid Peer ID — but the volume prevents honest peers from connecting.
Unlike an eclipse, the target's routing table isn't poisoned — it simply runs out of capacity to accept new connections.
Normal Operation
The target node (yellow) has available connection slots and communicates freely with honest peers. The Connection Manager enforces a high watermark — when reached, low-priority connections are pruned to make room.
Slow Connection Buildup
The attacker establishes connections to the target gradually — staying under rate limits. Each connection appears legitimate and goes through the full Noise/TLS handshake. The attacker maintains these connections by keeping them alive with periodic pings.
Connection Slots Filling
More attacker connections arrive. The target's connection slots are 80% consumed by attacker-maintained connections. New honest peers trying to connect start getting rejected. The Connection Manager prunes low-scored connections — but the attacker's connections score normally because they complete handshakes properly.
Target Exhausted
The target's connection slots are fully consumed. All honest peer connections have been pruned or cannot be established. The target is effectively isolated — not because its routing table is poisoned, but because it simply cannot accept any more connections. Unlike an eclipse, the target knows it's under attack but cannot do anything about it.
Defense: Per-Peer Limits
The Resource Manager's per-peer limits are the primary defense: (1) Max connections per peer — no single source can consume all slots; (2) Max connections per IP/subnet (CIDR limits) — prevents Sybil-scale exhaustion from one machine; (3) Connection Gater blocks connections from known-bad peers before resource allocation; (4) Decay-based scoring deprioritizes peers that only consume without contributing.
Technical Details
Connection Manager Watermarks
When connections exceed the high watermark, the system enters an aggressive pruning phase to prevent resource exhaustion.