Guest OS Customization on Ubuntu VM using Netplan with both IPv4 and IPv6 on a single network interface creates two routes in the Yaml file.

Products

• VMware
• VMware vCenter Server 7.0
• VMware vCenter Server 8.0

Issue/Introduction

Symptoms:

After upgrading vCenter version to 7.0 u3 Build 24026615, when applying Guest OS Customization to an Ubuntu VM or Template that uses Netplan for network configuration, it creates two routes for a single interface with both  IPv4 and IPv6 in Yaml file. This setup contradicts the Netplan documentation

Environment

 vCenter 7.03 Build 24026615

 

Cause

Netplan recommend below configuration for multiple routes in yaml file
 
network:
  version: 2
  renderer: networkd
  ethernets:
    enp3s0:
      addresses:
        - xx.xx.xx.xx/xx
        - xx:xx:xx:xx:x:xx:xx:xxx/xx
      routes:
        - to: default
          via:  xx.xx.xx.xx
        - to: default
          via: xx:xx:xx:xx:x:xx:xx:xxx/xx

When applying guest OS customization on vCenter 7.0 U3 build 24026615, we find the YAML file below containing two routes

network:
  version: 2
  renderer: networkd
  ethernets:
    enp3s0:
      addresses:
        - xx.xx.xx.xx/xx
        -xx:xx:xx:xx:x:xx:xx:xxx/xx
      routes:
        - to: default
          via: xx.xx.xx.xx
      routes:
        - to: default
          via: xx:xx:xx:xx:x:xx:xx:xxx/xx

Resolution

Currently, there is no resolution. Issue will be fixed in future release of vCenter

Workaround:
Manually edit the YAML file to create single route.

Additional Information

Netplan documentation