k3s agent on google cloud vm using the wrong ip

[fima-methodic]

I have a k8s cluster that was installed by k3s.
The k3s server is installed on an on-prem server, and there is also a k3s agent that is installed on an another on-prem server.
Both instances has Addresses.InternalIP and flannel.alpha.coreos.com/public-ip pointing the external ip of each on-prem server and everything is working perfectly (the communication between the nodes and pods is working as expected).
I've added another k3s agent on a google cloud vm, but in this case the the Addresses.InternalIP and flannel.alpha.coreos.com/public-ip are pointing to the internal ip of the google cloud vm instead of the external ip.
This is creating a problem - the agent is created and registered but there is no communication between the server + on prem node and the google cloud vm agent. (pods are not initialized and the metrics-server is unable to get any data from this node)

I have added the --node-ip flag which changed the Addresses.InternalIP and it did solved part of the problem - pods are being created, the metrics server is reaching this node and receiving data. but flannel.alpha.coreos.com/public-ip is still using google cloud's vm internal ip (through network interface) i have tried to override it with --flannel-conf but it didn't worked.

Is there a way to configure it to use only google cloud's vm external ip? Or it just not possible to use a google cloud's vm as a k3s-agent if the k3s-server is running on an on-prem server?

The k3s server and nodes:
k3s-version - v1.31.6+k3s1
OS - ubuntu 24.04

[brandond]

flannel.alpha.coreos.com/public-ip is still using google cloud's vm internal ip

If you want to change the public IP, you should set --node-external-ip. Not --node-ip.

See also the --flannel-external-ip option:
https://docs.k3s.io/networking/basic-network-options

[fima-methodic]

Thanks for the reply :)
Do i need to use the Embedded k3s multicloud solution and switch flannel to wireguard-native or i can keep it as vxlan and just add --flannel-external-ip option?