docs/TAILSCALE.md

Connecting machines with Tailscale (recommended)

DaisyChain needs every node reachable by a stable IP on one interface. Tailscale gives you exactly that: a private mesh where each machine gets a 100.x.y.z address on the tailscale0 interface, reachable P2P across NATs and different networks — no port-forwarding.

1. Install on every machine

• Linux: curl -fsSL https://tailscale.com/install.sh | sh
• Windows / macOS: https://tailscale.com/download

Bring each up (same tailnet / account) and note its IP:

sudo tailscale up
tailscale ip -4          # e.g. 100.101.102.10
tailscale status         # see every machine + IP

2. Configure the cluster

Pick one machine as rank 0 and use its Tailscale IP as MASTER_ADDR. On every machine:

export MASTER_ADDR=100.101.102.10
export MASTER_PORT=29560
export WORLD_SIZE=3
export GLOO_SOCKET_IFNAME=tailscale0   # pin gloo to the mesh NIC
export RANK=0                           # 1, 2, ... on the others
daisychain-train

GLOO_SOCKET_IFNAME=tailscale0 is the important line — it stops gloo from wandering onto a LAN/VPN/Docker interface.

3. Verify

Run daisychain-dashboard (point config/nodes.example.json at the Tailscale IPs). Green banner = every node reachable and ports open → launch training.

On Windows the Tailscale interface name differs and gloo tensor collectives are unstable anyway — prefer Linux nodes or Docker for the actual training.