ZTM Tunnel Skill

Create and manage TCP/UDP tunnels between ZTM network endpoints.

Prerequisites

1. ZTM Agent must be running

   ztm start agent
   

2. Join a mesh network

   ztm join <mesh-name> --as <your-endpoint-name> --permit <permit-file.json>
   

3. Tunnel app must be installed

   ztm app install tunnel
   

Concepts

• Inbound: The local endpoint that listens for connections and forwards them to the remote
• Outbound: The remote endpoint that receives connections and forwards them to target services
• Tunnel: A complete connection consisting of inbound + outbound

List Tunnels

List all tunnels in the mesh:

ztm tunnel get tunnel

List inbound tunnels (local listening ports):

ztm tunnel get inbound

List outbound tunnels (remote targets):

ztm tunnel get outbound

Create a Tunnel

Scenario: Expose a local service to another endpoint

Step 1: On the remote endpoint (outbound), specify target services:

ztm tunnel open outbound my-tunnel --targets 192.168.1.100:8080

Step 2: On the local endpoint (inbound), set up port forwarding:

ztm tunnel open inbound my-tunnel --listen 0.0.0.0:9000 --exits <remote-endpoint-id>

This creates a tunnel where:

• Local port 9000 listens for connections
• Connections are forwarded to remote endpoint
• Remote forwards to 192.168.1.100:8080

Quick One-Liner (Same Command on Both Ends)

Create both ends at once by running on respective endpoints:

# On endpoint A (listening side)
ztm tunnel open inbound tunnel-name --listen 0.0.0.0:9000 --exits <endpoint-B-id>

# On endpoint B (target side) 
ztm tunnel open outbound tunnel-name --targets 127.0.0.1:8080

Delete a Tunnel

Close the inbound end:

ztm tunnel close inbound my-tunnel

Close the outbound end:

ztm tunnel close outbound my-tunnel

Tunnel Details

View detailed tunnel information:

ztm tunnel describe tunnel tcp/my-tunnel

View inbound details:

ztm tunnel describe inbound tcp/my-tunnel

View outbound details:

ztm tunnel describe outbound tcp/my-tunnel

Common Use Cases

Access Home Server from Anywhere

# On home endpoint
ztm tunnel open inbound home-server --listen 0.0.0.0:22 --exits <office-endpoint-id>

# On office endpoint
ztm tunnel open outbound home-server --targets 192.168.1.10:22

Forward Web Service

# Remote endpoint exposes local web service
ztm tunnel open outbound web-tunnel --targets 192.168.1.100:80

# Local endpoint listens on port 8080
ztm tunnel open inbound web-tunnel --listen 0.0.0.0:8080 --exits <remote-endpoint-id>

UDP Tunnel (for DNS, VoIP, etc.)

ztm tunnel open outbound dns-tunnel --targets 8.8.8.8:53
ztm tunnel open inbound dns-tunnel --listen 0.0.0.0:5300 --exits <remote-endpoint-id>

Troubleshooting

Check if ZTM agent is running:

curl http://localhost:7777/api/status

Check mesh status:

ztm get mesh
ztm get ep

Check installed apps:

ztm get app

If tunnel app is not installed:

ztm app install tunnel

View tunnel app logs:

ztm log app tunnel

Configuration

ZTM CLI config is stored in ~/.ztm.conf:

{
  "agent": "localhost:7777",
  "mesh": "my-mesh-name"
}

Or set via environment:

export ZTM_AGENT=http://localhost:7777
export ZTM_MESH=my-mesh-name

API Reference

For programmatic access, use the ZTM Agent HTTP API:

# Get all tunnels
curl http://localhost:7777/api/meshes/{mesh}/apps/ztm/tunnel/api/tunnel

# Get inbound tunnels
curl http://localhost:7777/api/meshes/{mesh}/apps/ztm/tunnel/api/inbound

# Create inbound
curl -X POST http://localhost:7777/api/meshes/{mesh}/apps/ztm/tunnel/api/inbound/tcp/tunnel-name \
  -H "Content-Type: application/json" \
  -d '{"listens":[{"ip":"0.0.0.0","port":9000}],"exits":["endpoint-id"]}'