WZ-IT supports setup and network planning for Proxmox on IONOS. Arrange a conversation.
As of October 2026. Recheck product conditions before making changes.
Contents
- Which IONOS documentation applies?
- Distinguish NAT and public guest IPs
- Document IP assignments and return paths
- Private networks and acceptance
Which IONOS documentation applies?
The search term “Multiple public IPs IONOS Proxmox” does not identify a universal network configuration. The guidelines for hosting virtual machines cover the listed older server products in server administration. They warn against public bridging because of unauthorized MAC addresses. The Cloud Panel guide instead describes a public network allowing multiple MAC addresses and manual guest configuration with multiple IPs.
This distinction applies as of October 2026. Check the specific product line and network allocation.
Distinguish NAT and public guest IPs
| Variant | Guest address | Establish before implementation |
|---|---|---|
| NAT behind host IP | Private IP | Translation and inbound publication |
| Route public IP to guest | Allocated public IP | Host forwarding, provider route, return path |
| Public bridging | Public IP and own MAC | Explicit permission for guest MAC |
| Map several IPs through NAT | Private IP per guest | Explicit source and destination NAT mapping |
The older IONOS guide lists forwarding, a route and address assignment inside the guest for a dedicated public guest IP. This does not authorize arbitrary virtual MACs. The Proxmox networking documentation explains bridging, routing and NAT; the table is a planning aid, not product-specific authorization.
Document IP assignments and return paths
Before making changes, create an assignment list: public IP, product/server, prefix, provider gateway, guest, guest gateway and selected mode. Read network values from the relevant account configuration; do not guess gateways from neighboring addresses.
- Check console/rescue access and save current network and firewall configuration.
- Assign just one additional IP to an isolated guest first. Preserve the existing management connection.
- For routed networking, check the host route to the guest, forwarding and guest return route together.
- With NAT, explicitly define both inbound destination mapping and outbound source address; record filter rules separately. OPNsense NAT distinguishes these functions.
- Configure public bridging only after confirming permitted MAC usage for this server.
Do not assign an unchanged host IP to a guest as an independent endpoint. An additional IP in the account is not evidence of a complete guest configuration.
Private networks and acceptance
An IONOS Private Network is a private VLAN path for assigned dedicated servers. It does not replace public IP assignment. Plan cluster communication and private guests separately from public service addresses.
Recommended acceptance: map each public IP to its intended service from outside; check outbound source IP per guest; test ports that are not allowed; verify DNS and return paths. Then check reboot and, where applicable, guest migration. If connectivity fails, compare product assignment, permitted MACs, routes and filters individually rather than changing several network modes at once. Record results, rollback and unresolved provider questions.
Related guides
- Proxmox Cluster Networking on IONOS: Private Network with VLAN (802.1Q)
- Proxmox on IONOS: private VM network behind one IP
WZ-IT supports setup and network planning for Proxmox on IONOS. Arrange a conversation.
