for the DIR-853 ET A3 (and its A3E variant) is on D-Link's Russian FTP server. This is the link you are searching for :
Always verify that your router's sticker says H/W Ver: A3 . Installing firmware meant for Revision A1 or A2 on an A3 device can cause a permanent "brick" (hardware failure). 🛠️ Pre-Update Checklist Before starting the upload, follow these stability rules: dir853 et a3 firmware update link
The suffix refers to a specific regional hardware variant (often Eastern Europe / Russia / CIS region, or a specific production batch). Firmware is not interchangeable between revisions. for the DIR-853 ET A3 (and its A3E
: Use the OpenWrt Firmware Selector to download custom firmware that expands your networking capabilities. OpenWrt Installation Guide : Consult the OpenWrt Wiki Page for DIR-853 A3 OpenWrt Installation Guide : Consult the OpenWrt Wiki
The primary link for community-supported firmware is the :