scan

Discover devices running connecto listen.

Usage

connecto scan [OPTIONS]

Description

The scan command discovers devices on your network that are running connecto listen. It tries discovery methods in order, falling back when one finds nothing:

1. mDNS discovery - finds devices advertising the _connecto._tcp service
2. Subnet scanning - scans your local subnets, saved subnets, and any --subnet arguments
3. Ad-hoc network scan - looks for Connecto ad-hoc WiFi networks (created with connecto listen --adhoc)
4. Bluetooth LE - with --bluetooth, scans for BLE-advertised devices (requires a build with the bluetooth feature)

Options

Examples

Basic scan

connecto scan

Output:

  CONNECTO SCANNER

→ Scanning for devices...

✓ Found 2 device(s):

[0] mydesktop (192.168.1.55:8099)
[1] workstation (192.168.1.100:8099)

To pair with a device, run: connecto pair <number>

Scan additional subnet

connecto scan --subnet 10.0.2.0/24

Scan multiple subnets

connecto scan -s 10.0.2.0/24 -s 10.0.3.0/24

Discovery methods

mDNS Discovery

mDNS (multicast DNS) automatically finds devices on the same subnet. No configuration needed.

Limitations:

• Only works within the same subnet
• May be blocked by some network configurations

Subnet scanning

For VPN or cross-subnet scenarios, Connecto scans IP ranges directly. Each responding host is probed with a real protocol handshake, so only actual Connecto listeners show up — see Protocol.

Saved subnets are automatically included:

connecto config add-subnet 10.0.2.0/24
connecto scan  # Now includes 10.0.2.0/24

One-time subnets can be specified with --subnet:

connecto scan --subnet 10.0.2.0/24

Ad-hoc networks

If nothing is found, Connecto looks for ad-hoc WiFi networks created by connecto listen --adhoc. When one is found, Connecto may briefly join it to probe for the listening host — your previous WiFi network is always restored before the results are printed, so pair by rejoining the ad-hoc network when you’re ready.

Network isolation hint

If you have a working network address but nothing answered, your router is likely isolating clients from each other (AP/client isolation). The scan output explains how to work around it with a direct WiFi network.

Device cache

Scan results are cached so that connecto pair <number> can resolve device numbers. The cache lives in your per-user cache directory (e.g. ~/Library/Caches/com.connecto.connecto/devices.json on macOS, ~/.cache/connecto/devices.json on Linux) — not in a world-writable location like /tmp.

Device numbers start at 0 and refer to the most recent scan.

Scan performance

Connecto scans up to 100 IPs concurrently with a 500ms timeout per IP.

No devices found?

If no devices are found:

1. Ensure the target is running connecto listen
2. Check firewall allows TCP 8099 and UDP 5353
3. For VPN, add the remote subnet: connecto config add-subnet <CIDR>
4. Try direct pairing: connecto pair <ip>:8099

See Troubleshooting for more help.