VM export, whether performed through vCenter or using OVF Tool, by default uses the ESXi host’s management network. However, the management network is typically not very fast, which can lead to performance issues during the export process and may also impact the overall performance of the management network itself.
If this is a concern, we recommend creating or using a separate VMkernel interface specifically for VM export.
On the ESXi host, create a new standard switch (VSS) or distributed switch (VDS), assign it an uplink to ensure network connectivity. Then create a new VMkernel (vmk) interface using a port group on this new switch. Assign a new IP address to this VMkernel interface, and finally, use OVF Tool to connect to this new IP address to export the VM.
A simple, typical OVF Tool command to export VM is,
ovftool --noSSLVerify vi://<new-IP-address>/<VM-name> <output-file>.ova
Please access this page https://developer.broadcom.com/tools/open-virtualization-format-ovf-tool/latest to download OVF Tool binaries and documentations.