5d91ca0efc
Review-driven session/transport fixes (each reproduced live against sharkd 4.6.7 before fixing): - raise the RPC stream limit to 16 MB: a full 1000-row frames page measures ~190 KB against the 64 KB StreamReader default, which failed the request with a 500 and desynchronized the resident session; a line-over-limit ValueError is now treated as a transport failure - verify JSON-RPC reply ids: a timed-out request's late reply was served as the next request's answer; timeouts, dead pipes, malformed and stale replies now kill the session for good instead - make check-spawn atomic under one manager lock: concurrent requests for the same pcap double-spawned sharkd and leaked the loser (process plus /tmp scratch copy) forever - refcount sessions and evict idle only (LRU, cap raised 8 -> 16): a tag with more sources than the cap respawned every source on every request, and concurrent requests could get their session killed mid-RPC (spurious 502) - map FilterError to sharkd's filter rejection (-13002) only; other engine failures with a filter set are 502, not a client 400 - detail: accept an optional frame_number to disambiguate same-microsecond frames (ts is not unique within a pcap); drop the -8003 -> 404 mapping (the range is validated locally, engine errors are real faults); a failed hex read is a 404 instead of "hex": null - a pcap deleted mid-request is a 404, not a 500; the pcap-sized scratch copy runs off the event loop; server shutdown kills every resident session and drops its scratch directory - pin the packet-list layout through scratch-HOME Wireshark preferences: the column indexes are a contract the server owns (protocol-level column negotiation is rejected by sharkd 4.6.x) Range contract change (WebUI moved to an always-flat list): the merged frame list is returned in full, deliberately uncapped - truncated and per-second buckets are removed, frame_count always equals len(frames), and rendering cost is the client's concern (the window endpoint remains the incremental path).
This documentation is organized by AI with reference to actual code. AI can make mistakes — please verify against the source code when in doubt.
GNS3 Server Documentation
License
This documentation is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License (CC BY-SA 4.0).
⚠️ Important - ShareAlike Requirement: If you create derivative works based on this documentation (including software that incorporates substantial portions of the documentation), your work must also be licensed under CC BY-SA 4.0 or a compatible license (such as GPLv3).
- 📄 Full License Text: See docs/LICENSE
- 🔗 License URL: https://creativecommons.org/licenses/by-sa/4.0/
- 📖 Compatibility: https://creativecommons.org/compatiblelicenses
Dual License Structure:
- 📚 Documentation: CC BY-SA 4.0 (this directory)
- 💻 Software Code: GPLv3 (see root LICENSE)
Technical documentation for the GNS3 server project, covering features, AI Copilot, development setup, and known issues.
Directory Structure
docs/
├── README.md # This file
├── development-setup.md # Ubuntu 24.04 development environment setup
├── openapi.json # OpenAPI specification
├── features/ # Feature documentation
│ ├── compute-controller-setup.md # Controller + Compute architecture & configuration
│ ├── statistics-api.md # Aggregated statistics API for monitoring
│ ├── vnc-websocket-console.md # Browser-based VNC console via WebSocket
│ └── web-wireshark-business-process.md # Web Wireshark (Docker + xpra packet capture)
├── design/ # Design proposals & roadmaps (not yet implemented)
│ └── docker-image-type.md # Docker image types: vendor profile discriminator + registry
├── gns3-copilot/ # AI Copilot feature documentation
│ ├── netmiko_devices.md # Netmiko supported devices (366 types)
│ ├── template-based-configuration-roadmap.md # Future: template-based config with HITL
│ └── implemented/ # Implemented features
│ ├── chat-api.md # Chat API (SSE, session management)
│ ├── llm-model-configs.md # LLM model configuration system
│ ├── command-security.md # Command security and filtering
│ ├── context-window-management.md # Context window optimization
│ ├── node-control-tools.md # Node start/stop/suspend tools
│ └── multi-vendor-device-support.md # Multi-vendor device support
└── bugs/ # Known issues & bug reports
└── telnet-server-connection-race-condition.md
Features
Controller + Compute Setup (features/compute-controller-setup.md)
Architecture and minimum configuration for setting up GNS3 Controller with remote Compute nodes. Covers compute node config, controller registration, and multi-compute deployment.
Statistics API (features/statistics-api.md)
Aggregated server statistics API (GET /v3/statistics) for monitoring dashboards. Collects compute resources, project/node/link counts, and Web Wireshark container status in a single request.
VNC WebSocket Console (features/vnc-websocket-console.md)
Browser-based VNC console access via WebSocket. The Controller acts as WebSocket-to-WebSocket relay, and Compute bridges WebSocket to TCP for QEMU/Docker VMs. Supports noVNC clients.
API Error Responses (features/api-error-responses.md)
Unified error response format across all GNS3 API endpoints. Documents HTTP status codes, error types, and client-side error handling patterns.
Web Wireshark (features/web-wireshark-business-process.md)
Web-based packet capture analysis using Docker + xpra HTML5 client. Zero-install Wireshark experience directly in the browser, integrated with GNS3 topologies.
Marker (Traffic Insight) (features/marker-traffic-insight.md)
Real-time traffic insight via per-link BPF markers and project-level inherited definitions. A marker taps a link in uBridge, emitting match notifications and pcap capture on BPF hit; definitions fan out to every capable link automatically.
Marker Tag Replay (features/marker-tag-replay.md)
Aggregate playback across links keyed by tag: once every marker under a tag is paused, their pcaps merge into one timestamp-ordered timeline; frames are decoded on demand via tshark into an isomorphic JSON protocol tree. The cross-link delta of the same packet measures the intermediate node's forwarding latency.
Docker exec Console (Vendor NOS) (features/docker-exec-console.md)
Console for vendor NOS containers (SR Linux, XRd, …) whose CLI is a TUI off PID 1: runs the vendor CLI via the Docker exec API, plus GNS3_SKIP_INIT/GNS3_INTERFACE_NAMES boot knobs and SKIP_INIT volume persistence.
Cisco XRd Control Plane (features/vendor-nos-xrd.md)
Cisco XRd as a GNS3 Docker router: vendor path + shm/device injection (GNS3_SHM_SIZE/GNS3_DEVICES), config-file injection (extra_configs), udev masking (GNS3_MASK_UDEV) so privileged systemd containers don't disturb the host, and the host-readiness check.
IOL Images with iol-runner (features/iol-runner-docker.md)
Cisco CML containerized IOL (e.g. iol-xe/iol-xe:17-18-02) as GNS3 Docker routers: generic unix-socket NIO (GNS3_UNIX_SOCKET_NIO — adapters wired via AF_UNIX datagram socket pairs instead of TAP/netns) plus IOLDockerVM (GNS3_IOL_RUNNER=1 — per-start config generation, /tmp/run preparation, stale-socket cleanup, console on PID 1 stdio).
Design & Roadmaps (design/)
Docker Image Types (design/docker-image-type.md)
Proposed image_type discriminator on Docker templates plus a compute-side profile registry: vendor parameters graduate from environment markers into schema-gated fields, generic-feature applicability becomes declared capability data, and the existing markers remain as a compatibility fallback. Not a new node type — vendor images are content, not mechanism.
GNS3 AI Copilot (gns3-copilot/)
Implemented Features
| Feature | Description | Status |
|---|---|---|
| Chat API | SSE streaming, session management, token statistics | Implemented |
| LLM Model Configs | Multi-level model config (system/group/user) | Implemented |
| Command Security | Command filtering, dangerous operation detection, HITL | Implemented |
| Context Window Management | Token optimization, content filtering, compression | Implemented |
| Node Control Tools | Start/stop/suspend with batch ops and progress tracking | Implemented |
| Multi-Vendor Support | Cisco, Huawei, Ruijie, VPCS with custom Netmiko drivers | Implemented |
Reference
- Netmiko Supported Devices — 366 device types (154 SSH, 55 Telnet, 3 custom GNS3 drivers)
Roadmap
- Template-Based Configuration with HITL — Jinja2 templates with human-in-the-loop confirmations for device configuration and node creation
Known Issues (bugs/)
- Telnet Server Connection Race Condition —
getpeername()error when client disconnects during connection setup (High severity, Open) - Docker Link UDP Self-Loop — intermittent one-way link (both ends handed the same UDP port by an allocation race); fixed (Medium severity)
Development Setup (development-setup.md)
Quick-start guide for Ubuntu 24.04: install via PPA, set up dependencies, and run gns3-server from source.
Related Documentation
- GNS3 Server API Documentation — Interactive API docs (also available locally via
redoc.html) - GNS3 Web UI Documentation
- LangGraph Documentation
Last updated: 2026-09-01