Network Requirements

SwiftDrop requires specific network ports to be open for discovery and file transfer.

Ports used by SwiftDrop

Firewall configuration

Windows: SwiftDrop adds firewall rules automatically during installation. If you manually blocked it, re-allow it in Windows Defender Firewall → Allow an app.

macOS: When SwiftDrop first listens on a port, macOS shows an "Allow incoming connections?" prompt — click Allow.

Linux:

# UFW
ufw allow 47824/tcp
ufw allow 47823/udp

# iptables
iptables -A INPUT -p tcp --dport 47824 -j ACCEPT
iptables -A INPUT -p udp --dport 47823 -j ACCEPT

Router and Wi-Fi settings

Client isolation: Some routers (especially hotel and enterprise Wi-Fi) enable client isolation, which prevents devices on the same SSID from communicating. SwiftDrop cannot do LAN discovery when this is on. Contact your IT admin or switch to a network without isolation.

2.4 GHz vs 5 GHz split: If your router has separate SSIDs with different subnets, devices on different bands cannot see each other. Connect both devices to the same SSID.

Corporate networks

Key asks for your IT administrator:

1. Allow UDP broadcast on port 47823 within the WLAN segment.
2. Allow TCP inbound/outbound on port 47824 between endpoints in the segment.
3. Allow TCP outbound on port 47825 to relay.zashiron.org for Relay Mode.