Hi all, I'm evaluating Public Cloud solution.
I'm having a problem accessing to the public network via a shared private network and its vm-gate.
I created two almalinux instances and a private network (no dhcp, no gateway).
I associated a private IP address with one instance.
The other has both a private IP address and a public IP address.
VM_LAN: 10.1.3.168/16, gw 10.1.3.168
GATE: 10.1.3.168/16 + 152.228.XXX.XXX public
The two VMs respond correctly to pings between private networks.
In the GATE, I enabled connection sharing in the private network:
# sysctl -w net.ipv4.ip_forward=1
# firewall-cmd --add-masquerade --permanent
# firewall-cmd --query-masquerade --zone=internal --permanent
# firewall-cmd --zone=internal --change-interface=eth0 --permanent
# firewall-cmd --permanent --zone=internal --set-target=ACCEPT
# firewall-cmd --reload
From simulations on both another provider and local hypervisor, this configuration works without problems and I can reach Internet access from VM_LAN (e.g., tracepath 8.8.8.8 gives me the complete trace).
However, this doesn't happen via the OVH private network, see attached image. It seems like there's some blockage related to packet routing.
Have I forgotten something?
Is there something I need to enable in the vrack?
Does the OVH configuration prevent internet access from a VM on the private network via a VM-gate?
I've tried several times, including following guides/community forums and on pfsense/opnsense (rebuilding GATE) too, but the problem persists.
It seems like a network blockage.
Ideas?
Thank you very much for your support.
46112 
07.11.2018 12:32
Hello,
Thank you for providing such a detailed technical breakdown of your configuration. I am checking in to see if you are still experiencing this routing blockage between your private network and the public gateway?
If the issue persists, your configuration seems correct from an OS standpoint (IP forwarding, masquerading), but vRack networking sometimes requires specific attention regarding the gateway's IP configuration and how traffic is routed back.
Since your project involves Public Cloud and complex network architecture, I highly recommend joining the OVHcloud Discord. Our Cloud experts and the community are very active there and can provide real-time feedback on vRack routing specificities: 👉 https://discord.gg/ovhcloud
In the meantime, you might find some useful pointers regarding interface configuration and IP routing in our dedicated guide: 👉 Configuring an additional network interface in Public Cloud
Best regards,
^FabL