gns3-packet-capture

Apps & Automation

Capture network traffic on GNS3 links - start/stop captures, retrieve PCAP data

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How to use this skill

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Prompt to paste

I want to install this Agent Skill for this project in Codex.

Source SKILL.md: https://github.com/automateyournetwork/netclaw/blob/HEAD/workspace/skills/gns3-packet-capture/SKILL.md

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Copying this prompt does not install or run the skill. Review third-party files before use. Codex skill guide

GNS3 Packet Capture

Start and stop packet captures on links in GNS3 projects. Capture network traffic for analysis and troubleshooting.

When to Use

Troubleshooting network connectivity issues in a lab
Capturing traffic for analysis with Wireshark
Verifying routing protocol exchanges (OSPF, BGP, etc.)
Debugging application traffic
Learning about network protocols
Validating QoS or security policies

MCP Server

Command: python3 -u mcp-servers/gns3-mcp-server/gns3_mcp_server.py (stdio transport)
Requires: GNS3_URL, GNS3_USER, GNS3_PASSWORD environment variables

Available Tools

Tool	Parameters	What It Does
`gns3_start_capture`	project_id, link_id, capture_file_name?	Start packet capture on a link
`gns3_stop_capture`	project_id, link_id	Stop packet capture and finalize PCAP file
`gns3_get_capture`	project_id, link_id	Get capture file path and stream URL

Workflow Examples

Capture Traffic for Analysis

# First, identify the link to capture
"List all links in routing-test"

# Start capture on the link between router1 and router2
"Start capturing traffic on link abc123 in routing-test"

# Generate some traffic (ping, routing updates, etc.)
# ...

# Stop capture when done
"Stop the capture on link abc123 in routing-test"

# Get the PCAP file location
"Get capture info for link abc123 in routing-test"

Custom Capture Filename

# Start capture with custom filename
"Start capturing on link abc123 in routing-test as ospf_adjacency.pcap"

Live Streaming

# Get stream URL for live capture viewing
"Get capture info for link abc123 in routing-test"
# Returns stream_url for live PCAP streaming

Integration with Other Skills

gns3-link-management: List links to find the one to capture
gns3-node-operations: Ensure nodes are running before capturing
packet-analysis: Hand off PCAP data for deep inspection

Capture Output

PCAP Format: Standard libpcap format compatible with Wireshark
File Location: Stored on GNS3 server, path returned in response
Stream URL: Available for live capture viewing when capture is active

Error Handling

Error Code	Meaning	Resolution
GNS3_NOT_FOUND	Link doesn't exist	Use gns3_list_links to find valid link IDs
GNS3_CONFLICT	Capture already running	Stop existing capture first

Tips

Find the right link: Use gns3_list_links to see all connections and their IDs
Start before traffic: Begin capture before generating the traffic you want to analyze
Stop cleanly: Always stop capture to finalize the PCAP file
Use custom names: Descriptive filenames help organize multiple captures

Notes

Captures are stored on the GNS3 server
Link IDs are UUIDs from gns3_list_links
Only one capture per link at a time
Stop capture to ensure PCAP file is complete
All operations logged to GAIT audit trail