Understanding VM Networking

Understanding Anka VM networking

Prerequisites

  1. You’ve installed the Anka Virtualization package
  2. You’ve created your first VM Template
  3. You grasp how to modify VM settings (like network)

Basics

We use Apple’s VMNET interface with “Using DHCP” for networking.

By default Anka VMs use a shared networking configuration with the host. It’s a kind of NAT + DHCP.

❯ anka --machine-readable describe 12.2 | jq '.body.network_cards'
[
  {
    "mode": "shared",
    "controller": "virtio-net"
  }
]

Every time you start/resume a VM it will be assigned an IP:

❯ anka show 12.2
+---------+--------------------------------------+
| uuid    | 26c18e20-f67a-4387-a7b7-236a277bb424 |
+---------+--------------------------------------+
| name    | 12.2 (v2)                       |
+---------+--------------------------------------+
| created | Oct 18 13:57:57 2021                 |
+---------+--------------------------------------+
| vcpu    | 8                                    |
+---------+--------------------------------------+
| memory  | 12G                                  |
+---------+--------------------------------------+
| display | 1024x768                             |
+---------+--------------------------------------+
| disk    | 128GiB (22.84GiB on disk)            |
+---------+--------------------------------------+
| addons  | 3.0.0.135.8400565                    |
+---------+--------------------------------------+
| network | shared 192.168.64.6                  |
+---------+--------------------------------------+
| status  | running since Oct 25 15:48:36 2021   |
+---------+--------------------------------------+

❯ anka show 12.2 network
+------------+-------------------+
| mode       | shared            |
+------------+-------------------+
| controller | virtio-net        |
+------------+-------------------+
| ip         | 192.168.64.6      |
+------------+-------------------+
| mac        | ce:6b:90:1b:87:da |
+------------+-------------------+

If anka show does not display an IP, networking has either:

  1. Not fully started (give it a few more seconds).
  2. Networking cannot start due to some sort of host firewall or policy.
Within the VM, you can find an IP assigned for the host which can be used to ssh or transfer files out. To determine which IP is assigned to the host, execute ipconfig getoption en0 server_identifier (typically 192.168.64.1 for shared network mode and 192.168.128.1 for host network mode).

MAC Addresses

Anka will dynamically assign MAC addresses to your VM. You can assign custom MAC Addresses with the anka modify network --mac option.

Be aware that if you clone your VM Template with a specific MAC, both VMs cannot run at the same time
When using bridged networking mode for your VM, dynamic MAC Addresses are not guaranteed to be unique, though, reuse/collision is extremely unlikely. We do our best to prevent this with our randomization logic.

FAQs

  • Should your Firewall software be blocking VM networking, you need to whitelist the ankanetd process.

What’s next?