Asymmetric Routing Proxmox-ve: 6.2-1


Sep 3, 2020
Hi All,

I am having issues with asymmetric routing from within the guest Linux OS when assigning multiple NIC's to my VM's and configuring them via cloud-init. The IP's being assigned are public internet facing IP addresses and all use the same gateway for breakout. The IP addresses HAVE to respond on the NIC that the traffic comes in on otherwise eth0 by default sends the return traffic breaking the connection.

I can manually configure individual routing tables per interface within the OS to resolve the issue but, these rules do not persist reboots. I wrote a bash script to configure them on boot but that requires it to be built directly into the VM templates which can be painful to maintain. I did search on the forum but, I am not seeing many posts regarding asymmetric routing that are applicable to my use case.

My questions are these:
1.) Is there a better way to handle asymmetric routing from a proxmox perspective?
2.) Am I missing something in my configuration of cloud-init/proxmox that would enable it to be asymmetric aware?
3.) Does anyone have any suggestions/advice on how to handle asymmetric routing better?

* NB: this issue is on a VM guest OS level and not with proxmox itself *

Thank you in advance, any input is greatly appreciated!
Thank you for your response, Wolfgang! I will look through the documentation you linked and explore this as an option. I suspect the WHCMS plugin being used might limit what can be done unfortunately.


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