# Creating HVM Data Network

## About this task

An HVM Data Network creates a Linux VLAN interface on each host and maps it to a libvirt network. The system designs it to handle high-throughput in-guest storage traffic, such as iSCSI or NFS. It also allows MTU configuration to support jumbo frames.

NOTE

- You can apply MTU changes only to stopped VMs.
- Ensure to stop and start each VM after changing the MTU.
- Configure the MTU inside the guest VM interface. For example,

  ```
  ```
  ip link set <iface> mtu 9000
  ```
  ```

## Procedure

1. Navigate to Infrastructure > Network > Networks
2. Select + Add > HVM Data Network
3. Enter the following details in the Create Network: 

   - Group: Select the group to which the data network belongs from the drop down menu.
   - Network Service: Select the network service to which the data network belongs from the drop down menu.
   - **Name**: Enter the name of the network.
   - Display Name: Enter a user-friendly name. The system displays this name in the UI.
   - Labels: Enter comma-separated labels. Use labels to organize and filter networks.
   - Description: Enter a description to document the purpose or usage of the network.
   - Enable IPv4: Enable this option to configure IPv4 for the network.
   - CIDR: Enter the IPv4 address range in CIDR notation. For example, `192.168.1.0/24`. The system allocates IP addresses from this range.
   - **Resource Pool**: Select the HVM cluster where you want to create the network.
   - **VLAN ID**: Specify the VLAN ID that the NIC uses for hardware VLAN tagging (range: 1 – 4094).
   - **Network Interface**: Select the host network interface on which the system will create the VLAN sub-interface. The system uses `bond0` as the default and populates the list from interfaces discovered on the cluster hosts.
   - **MTU**: Select the Maximum Transmission Unit (MTU) value, use 1500 for standard frames or 9000 for jumbo frames.
   - Active: Select this checkbox to activate the network immediately upon creation.
   - DHCP Server: Select this checkbox to enable the internal Dynamic Host Configuration Protocol (DHCP) server for automatic IP assignment.
   - Allow IP Override: Select this checkbox to let workloads override their assigned IP addresses.
   - Network Pool: Select an IP address pool from the drop-down menu to allocate blocks for this network.
   - Domain: Select the network search domain from the drop-down menu to resolve hostnames.
   - IPv6 Options: Expand this section to configure Internet Protocol version 6 (IPv6) network settings.

     - Enable IPv6: Select this checkbox to activate IPv6 routing and addressing on the network.
     - CIDR : Enter the IPv6 network address and routing prefix block in CIDR notation.
     - DHCP Server: Select this checkbox to enable automatic IPv6 addressing via the internal DHCPv6 server
     - Network Pool: Select an IPv6 address pool from the drop-down menu to allocate blocks for this network.
   - Advanced Options: Expand this section to configure advanced routing and network proxy parameters.

     - Search Domains: Enter a space-separated or comma-separated list of DNS search domains to resolve short hostnames.
     - Proxy: Select a designated proxy server profile from the drop-down menu to route external network traffic.
     - Bypass Proxy For Appliance URL: Select this checkbox to route internal management appliance traffic directly instead of using the proxy server.
     - No Proxy: Enter a comma-separated list of IP addresses, subnets, or domains to bypass proxy server routing.
   - Guest Console Options: Expand this section to configure remote access properties for guest workloads.

     - VDI Gateway: Select the Virtual Desktop Infrastructure (VDI) gateway from the drop-down menu to handle remote console traffic.
     - SSH Jump Host: Enter the endpoint address of the Secure Shell (SSH) bastion or jump host to secure external administrative access.
     - SSH Jump Port: Enter the port number for the SSH jump host.
     - SSH User: Enter the credential username for the SSH jump host.
     - SSH Password: Enter the credential password for the SSH jump host.
     - SSH Keypair: Select an SSH key pair from the drop-down menu.
   - Group Access: Expand this section to manage access for specific groups.

     - Access Select this checkbox to grant network access to the group.
     - Default Select this checkbox to make this network the group default.
4. Click **Save Changes**

## Results

The system creates a Linux VLAN sub-interface on the selected host interface on each host and tags it with the specified VLAN ID. It reuses the interface if it already exists. The system then creates a libvirt network that maps to this VLAN interface.
