It’s not just you — many users report issues accessing http://updates.ironport.com/fetch_manifest.html, especially when performing offline upgrades of Cisco WSA (AsyncOS). The Cisco Community thread confirms this link frequently fails, and there’s no reliable alternate public mirror.
Why the Download Link Might Fail
Based on user-reported experiences:
The link often stops working partway through the download process
One user discovered that without a Virtual License Number (VLN), the system refuses: the manifest generation fails unless the correct serial number or VLN is provided and validated
Cisco Community
What You Can Do Instead
1. Confirm You Have a Valid VLN or Serial Number
WSA virtual instances require a VLN; physical models use the serial number.
Without a validated license, Cisco update servers won’t allow manifest generation or firmware download.
Use CLI command showlicense (virtual) or confirm via /show version (physical).
2. Try a Different Browser or Network
Some user reports suggest the Cisco UI may misbehave in certain browsers (Chrome vs Firefox), or may fail due to local network/firewall restrictions.
3. Use a Local Web Server & Host the Files Yourself
Once you successfully download the zip file:
Host it on a local IIS or Apache server with anonymous access.
Unzip into a root directory preserving folder structure (asyncos/coeus-… etc.).
Point your WSA upgrade settings to that local server (URL of the manifest XML).
4. If Download Still Fails → Contact Cisco TAC or Entitlements
One accepted solution:
Cisco TAC can manually provide the download link if you provide:
Model and serial number or VLN
Current and target AsyncOS version
Contract entitlements or proof of purchase
Use email ent-dl@cisco.com to request the file directly—even without a maintenance contract—for security-related updates.
Summary
Issue Recommendation
Fetch manifest link broken Validate VLN/serial and retry
Download stops or fails Try a different browser (Firefox) and network
Cannot access Cisco Update servers Use local web server method after zip download
Still unsuccessful Contact Cisco TAC or send email to ent-dl@cisco.com for manual download
