I am trying to launch strongswan Image as containers in single instance , connecting to host interface to container interface as bridge using pipework .Here while i am checking traffic from container to other host ,arp resolution is not happening(we are not allowed to assign IP to container interface as host IP range ).My question is should we launch containers in GCP using kubernetes only or any other procedure is present to launch containers with interfaces.
Regarding your concern that arp resolution is not happening, you can deploy a container image to the VM instance by using a container-optimized OS image.
Also, I recommend you to have a look at this article to know how Docker manages its containers networking. in this example two different outgoing IPs assigned to one interface.