[pve-devel] proxmox 2018 : add support for "virtual" network and network plugins ?

[Dietmar Maurer]

> On January 26, 2018 at 9:45 AM Alexandre DERUMIER <aderumier at odiso.com> wrote:
> 
> 
> > >>Sorry, too much information for me. Please can you explain why we need 
> > >>a floating IP?
> > 
> > floating ip are simply public ip which are used to do nat 1:1.
> > (internet->public ip -->nat 1:1-> private ip)
> > (they call them floating, because you can reassign them to another private
> > ip
> > on the fly ..but it's just nat).
> 
> >>But why do we need it? Can't we use the host IP to masquerade private ip?
> 
> This is not masquerade (s-nat, multiple private ip -> 1 public ip), this is
> nat 1:1 (the reverse way, internet->multiple vm ip public).
> 
> host: 89.248.0.1 -> vm1 192.168.0.1
> host: 89.248.0.2 -> vm2 192.168.0.2
> host: 89.248.0.3 -> vm3 192.168.0.3
> 
> iptables -t nat -A POSTROUTING -o eth0 -s 192.168.0.1 -j SNAT --to-source
> 89.248.0.1
> iptables -t nat -A PREROUTING -i eth0 -d 89.248.0.1 -j DNAT --to-destination
> 192.168.0.1

Why does the VM not use the public IP directly?