SSH and root access

Every Linux server comes up with OpenSSH on port 22 and root allowed with your keys, or with a generated password if you registered none.

SSH keys

Add keys under SSH keys (ed25519 or RSA ≥ 2048, one per line, the fingerprint is shown). Pick up to 5 when you order; they are written to /root/.ssh/authorized_keys before first boot. Keys added later are not pushed to running servers: add them yourself.

ssh-keygen -t ed25519 -C "laptop"
cat ~/.ssh/id_ed25519.pub     # paste this in the console

Root password

With no key selected, a 24-character password is generated, stored so that the server page can show it, and erased from our side when the server is cancelled. Change it at first login and switch to keys:

passwd
mkdir -p ~/.ssh && chmod 700 ~/.ssh
echo 'ssh-ed25519 AAAA... laptop' >> ~/.ssh/authorized_keys
sed -i 's/^#\?PasswordAuthentication.*/PasswordAuthentication no/' /etc/ssh/sshd_config && systemctl reload ssh

Address and hostname

Each server has one public IPv4 with reverse DNS and a hostname of the form srv-xxxx.rey.dedigpu.cloud (the region code in the middle). Both are on the server page and in /api/v1/servers.

First login

nvidia-smi                  # or rocm-smi on MI300X
nvidia-smi topo -m          # NVLink topology on multi-card servers
lsblk                       # the NVMe devices
ip -br addr                 # the public address

Hardening we recommend

• Keys only, no password authentication (above).
• A host firewall. Nothing sits in front of the server: ufw default deny incoming; ufw allow 22; ufw enable on Ubuntu, then open what you serve.
• Reach template ports (Jupyter, ComfyUI, vLLM) through an SSH tunnel rather than exposing them: ssh -L 8888:localhost:8888 root@….
• Unattended security updates: apt install unattended-upgrades.

Windows

Windows Server 2022 servers come with RDP on port 3389 and the Administrator password on the server page. See Windows Server.