NetNS

NetNS is the "network namespace" support for Linux.

Problems With Sharing Public IP

An interface in NetNS belongs to exactly one namespace. This presents a problem, since we want virtual nodes to share the node's public IP interface.

Possible workarounds:

• NAT: Give each virt node a private IP space, and NAT its outbound traffic. Forward certain ports on the public IP address to private IPs based on some port reservation table.
• Hack NetNS to allow sharing an address/interface between namespaces. No idea how hard this would be.
• The VINI plan: switch back and forth between two namespaces. Have to be in one namespace to talk to the outside world, and another to talk to the "experimental net". This might be very awkward, and require that a lot of software run on the nodes be customized: Mike will try it out.
• Look at other network virtualization packages - like OpenVZ. This would amount to a fundamental re-thinking of a lot of things.