Azure AD B2C: error for on-premise ad fs as SAML identity provider

Question

I was trying to add our on-prem AD FS as SMAL identity provider in azure ad b2c. I followed this document and finished all steps.

Then I tried the Run now endpoint (from aad b2c custom policy), and clicked the new IDP button (MY AD FS), I got the error: AADB2C: Unable to connect to the metadata endpoint 'https://MY.ADFS.COM/federationmetadata/2007-06/federationmetadata.xml'

Some notes:

• I run the test from the AD FS Server machine
• I can access the metadata directly from URL https://MY.ADFS.COM/federationmetadata/2007-06/federationmetadata.xml in browser (on the AD FS Server machine)

Not sure what I'm missing. Does it matter the AD FS server is corpnet wide only? Please help

Answer 1

I got help from Microsoft. To resolve this error, just put the metadata file on a public storage so that B2C can access it.