GNS3 Link Management

Create and manage links between node interfaces in GNS3 projects. Build network topologies by connecting devices and isolate nodes for testing.

When to Use

• Connecting two network devices together
• Building out a network topology
• Viewing existing connections in a lab
• Removing links between devices
• Isolating a node without deleting its links
• Re-enabling links after isolation testing

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_list_links | project_id | List all links with connected nodes and interfaces | | gns3_create_link | project_id, node1, port1, node2, port2 | Create a link between two interfaces | | gns3_delete_link | project_id, link_id | Delete a link | | gns3_isolate_node | project_id, node_id, isolate | Disable/enable all links to a node |

Interface Name Formats

The tools support multiple interface naming conventions:

| Format | Example | Adapter | Port | |--------|---------|---------|------| | eth# | eth0, eth1 | 0 | 0, 1 | | Ethernet# | Ethernet0 | 0 | 0 | | Gi#/# | Gi0/0, Gi0/1 | 0 | 0, 1 | | GigabitEthernet#/# | GigabitEthernet0/0 | 0 | 0 | | Fa#/# | Fa0/0, Fa0/1 | 0 | 0, 1 | | e# | e0, e1 | 0 | 0, 1 | | port# | port0, port1 | 0 | 0, 1 | | #/# | 0/0, 0/1 | 0 | 0, 1 |

Workflow Examples

Build a Topology

bash
# Connect router to switch
"Connect router1 Gi0/0 to switch1 eth0 in routing-test"

# Connect switch to another router
"Connect switch1 eth1 to router2 Gi0/0 in routing-test"

# Connect hosts to switch
"Connect host1 eth0 to switch1 eth2 in routing-test"

View Topology

bash
# List all connections
"List all links in routing-test"

Isolate for Testing

bash
# Isolate a node (disable all its links)
"Isolate router1 in routing-test"

# Test behavior with router1 disconnected...

# Re-enable links
"Unisolate router1 in routing-test"

Clean Up

bash
# Remove a specific link
"Delete the link between router1 and switch1 in routing-test"

Integration with Other Skills

• gns3-project-lifecycle: Create project first
• gns3-node-operations: Add nodes before connecting them
• gns3-packet-capture: Capture traffic on links

Error Handling

| Error Code | Meaning | Resolution | |------------|---------|------------| | GNS3_NOT_FOUND | Node or link doesn't exist | Check names/IDs | | GNS3_CONFLICT | Interface already connected | Check existing links first | | GNS3_VALIDATION | Invalid interface format | Use supported naming conventions |

Notes

• Links can only be created between existing nodes
• Each interface can only have one link
• Isolating a node disables links without deleting them
• Link IDs are UUIDs - use gns3_list_links to find them
• All operations logged to GAIT audit trail