Why might a FortiGate not receive push updates from the FortiGuard Distribution Network?

A FortiGate device relies on uninterrupted communication with the FortiGuard Distribution Network (FDN) to receive essential updates, such as antivirus definitions, intrusion prevention signatures, and other security-related information. When there is a Network Address Translation (NAT) device situated between the FortiGate and the FDN, it can lead to several potential issues that may hinder the FortiGate's ability to receive these updates.

NAT modifies IP address information in the packet headers as packets pass through the device, which can obscure the original source or destination IP addresses. This can create complications in the communication process required for the FortiGate to authenticate with the FDN. If the NAT device is not configured properly to handle the communications or if it fails to maintain session integrity, the FortiGate may find it difficult, if not impossible, to establish a successful connection to FDN for those critical push updates.

Additionally, NAT can impact the return path of the packets, potentially losing update requests or replies, which makes it an important factor to consider in networking setups that need reliable updates for security operations. Proper configuration and understanding of NAT devices are crucial to ensure that updates can be successfully received by the FortiGate.

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