Configure the VMware Cloud Director Appliance to Use Jumbo Frames

To improve the network use and throughput and to lower the CPU use, you can configure the VMware Cloud Director appliance to use Jumbo Frames.

The standard Maximum Transmission Unit (MTU) size of an Ethernet packet is 1500 bytes. Jumbo Frames are packets larger than the standard size. The larger Ethernet frame sizes reduce the overhead payload data, they have fewer frames that the network devices must process, and can help reduce latency.

Prerequisites

Verify that all devices along the network path are capable of handling Jumbo Frames. Fragmentation or packet loss might occur if some devices are not capable of handling Jumbo Frames.

Procedure

Log in directly or by using an SSH client to the VMware Cloud Director appliance console as root.
Navigate to the interface configuration directory.
```
cd /etc/systemd/network
```
Confirm which interfaces you need to configure.
```
route -n
```
- eth0 - interface for HTTP, console, API, and VMware Cloud Director appliance management interface traffic
- eth1 - interface for PostgreSQL traffic
To change the Maximum Transmission Unit (MTU) size, use ifconfig.
```
ifconfig interface_selection mtu 9000
```
For example, to change the MTU size for the eth1 interface, run the following command.
```
ifconfig eth1 mtu 9000
```
To make the changes persistent, edit the specific interface or interfaces.
```
vi 10-interface_selection.network
```
Add the Maximum Transmission Unit (MTU) configuration parameter.
```
[Link]
MTUBytes=9000
```

Example

[Match]
Name=interface_selection
[Network]
Domains=vcloud.local vcloud.local
Gateway=x.x.x.x
Address=x.x.x.x/x
DHCP=no
[DHCP]
UseDNS=false
[Link]
MTUBytes=9000