Proxmox Ssh Safety

Proxmox SSH & Connection Safety

OpenWrt SSH Stability Requirements

1. After OpenWrt network restart, the LAN IP changes (e.g., 192.168.1.1 → 10.10.10.1). The bootstrap SSH connection will hang forever unless ConnectTimeout is set.

Baseline OpenWrt SSH Configuration

2. Required SSH args for baseline (password auth) OpenWrt connections:

   ansible_ssh_common_args: >-
     -o ProxyJump=root@{{ ansible_host }}
     -o StrictHostKeyChecking=no
     -o UserKnownHostsFile=/dev/null
     -o PubkeyAuthentication=no
     -o ConnectTimeout=10
     -o ServerAliveInterval=15
     -o ServerAliveCountMax=4
   

Security Hardened OpenWrt SSH Configuration

3. After security hardening (M1), SSH switches to key auth. Replace PubkeyAuthentication=no with -i <key_path> and remove sshpass:

   ansible_ssh_common_args: >-
     -o ProxyJump=root@{{ ansible_host }}
     -o StrictHostKeyChecking=no
     -o UserKnownHostsFile=/dev/null
     -o ConnectTimeout=10
     -o ServerAliveInterval=15
     -o ServerAliveCountMax=4
     -i {{ lookup('env', 'OPENWRT_SSH_PRIVATE_KEY') }}
   

SSH Configuration Reasoning

4. The group reconstruction task file (tasks/reconstruct_openwrt_group.yml) auto-detects which auth method is active by checking deploy_stamp state and the OPENWRT_SSH_PRIVATE_KEY env var.

5. ConnectTimeout=10: Prevents infinite hang when LAN IP changes.

6. ServerAliveInterval=15: Prevents connection drop during local Ansible tasks (set_fact sequences) that don't generate SSH traffic.

Connection Safety Rules

7. NEVER retry SSH to the old bootstrap address after LAN reconfiguration.

8. Always use ProxyJump through the Proxmox host for OpenWrt connections to maintain connectivity through network topology changes.