Virtual Machine Multiple IP

Community Support
1

Hi there, I know that it has been discussed before, but something i can’t figure something.

My issue is secondary interface in any machine (CentOS 7.x, Debian 7/8, Ubuntu 18.XX) does not respond to ping from external network or inside the bridge.

The bridge is standard nothing to it, firewall is fully disabled and no filtering to it.

IP’s are from an 172.16.16.0/24

eth0: 172.16.16.2/24
eth1: 172.16.16.3/24

If I make some modification in the virtual machine like rt_tables, and source based routing I can access secondary ip.

Now does opennebula have in one context the commands necessary for rt_tables or some kind of setup to make the secondary network interface responsive ?

Thank you.

2

You should use field “Start Script” in VM -> Conf (Update Configuration) -> Context (Configuration)

3

Good morning, that can resolve the issue if I make the script for rt_tables and routing by source per table. I’m interested if I have a problem local with my deployment, example if I add second interface to any machine that share the same subnet just the first ip will respond …

4

I’ve done your experiment on Ubuntu, two addresses were respond to ping, but according to tcpdump all traffic transferred through eth0.
I think, you’d better if you use the subinterfaces (secondary IP) on eth0.

1 Like
5

Hi there, do the experiment on centos 7 I’m curious what it will be the result. I know about the alias about interface, but we are trying to rely on the opennebula templates.

6

Hello,

In OpenNebula 5.8 there is a new feature that allow you to have more than one IP on an interface.

Here you have the GitHub ticket: https://github.com/OpenNebula/one/issues/911

You can use them through the CLI and Sunstone. Try it and let us know if you find some bugs or improvements.

7

hi sir,
I try add mutil ip add in VM but it not working. u can help me ?

8

Hello @nguyen.tran

What kind of error do you get? Do you have context packages installed in the VM?

Best,
Álex.

9

i download image frome marketplace. and how to add context packages in VM?
This is no error. but i dont ping this IP secondary when add it.

10

You need to check the VM inside, to see if the IP has been added and then check the network configuration in your host.

Best,
Álex.