OVF Tool import fails with "413 Request Header Fields Too Large" in Cloud Director

Products

• VMware Cloud Director

Issue/Introduction

When attempting to import an OVF or OVA into VMware Cloud Director using the OVF Tool, the VMDK process fails but the descriptor.ovf is uploaded successfully. OVF Tool logs detail a 413 Headers error or a "Request Header Fields Too Large" message in the OVF Tool output. This error consistently prevents the successful upload of VMDKs despite the OVF Tool appearing to be configured correctly.

Environment

• 10.3
• 10.4
• 10.5
• 10.6

Cause

The issue originates from network infrastructure or security appliances positioned between the OVF Tool client and the Cloud Director cells. While the Cloud Director application and correctly configured Load Balancers are designed to handle standard header sizes, certain internal network devices, proxies or firewalls may have restrictive header inspection or buffer limits. These devices drop the packets or return the 413 status code before the traffic reaches the application layer.

Resolution

To resolve this issue, the network path must be validated to ensure it supports the necessary header sizes.

• Confirm the Load Balancer is configured to allow large header sizes in accordance with VMware Cloud Director documentation. If the Load Balancer settings are already verified, the bottleneck resides elsewhere in the network.
• Execute a packet capture (such as tcpdump or Wireshark) at both the source machine and the Cloud Director cell simultaneously. By comparing these captures, you can identify exactly where the 413 error is generated or where the session is being terminated.
• Run a curl command from the source to the target including ports 443 and 902 to determine communication.
• Review logs on firewalls (including NSX, ESXi and vCenter) and proxies. Many security appliances default to a header limit that is too restrictive for the metadata-heavy communication used by the OVF Tool.