Public IPs vs dedicated IPs

[Alejandro Lengua Vega]

We are currently setting up public IPs to some of the VMs we are creating
but we have been wondering if it could be better to use private ones
taking in count that they will speak to each other for consulting data.
(i.e. vm1: web server, vm2: db server)

In other words: Do using private IPs have provide better performance for internal communications?

 

[Craig St George]

I doubt better performance
what we do in this case is each if the VM have a private Nic . Or 2 eg front and back
and we have Vlans for that

So Web server to DB server over private
Or Proxy Server to Web server over private and Web server to DB or Apps server over private

Then only the Proxy has the Public IP but that is probably first hitting our shared firewall and then Nat over to the other nic card on the Proxy which also has a private IP

Of you could use the Proxmox firewall and the public IP would be on one side of the Proxy or Webserver
Not for performance but for security reasons

 

[Alejandro Lengua Vega]

I went ahead and started assigning private IPs to the VMs.
Now my problem is how do I give them Internet access to download updates.
According to this link this can't be done from the GUI
https://cyberpersons.com/2016/07/27/setup-nat-proxmox/
Any suggestion? Am I correct? I am using Proxmox 5.2

 

[HE_Cole]

Hey There!

I am new to promox, but i have been a network engineer for over ten years so i belive can answer your network related questions.

n other words: Do using private IPs have provide better performance for internal communications?

The answer to this NO, Using a public IP or private IP offers the same performance locally. Linux has a routing table for routes it has destinations too. It does not differentiate between a public or private IP locally a route is a route one is NOT faster than the other.


If you are only using private IP's then NAT is your only option to access to internet from your VM's. NAT is part of Private IP Address ''FYI'' RFC-1918.

If your already NAT'ing else were and NAT again its called double NAT and is not the greatest thing to do as latency can suck among other things.


I hope this helps some.