Sub Domain https redirect to Sharepoint online sites

[mikkydoos]

Hi all,

 

Could do with a bit of help on troubleshooting this.....

 

I'm trying to https redirect a sub domain to a Sharepoint site   (tenant.sharepoint.com/sites/my-site)   and am getting the browser error: ERR_SSL_PROTOCOL_ERROR in all browsers.

 

I'm pretty sure this is due to there not being an SSL certificate on the sub domain.  There is an SSL certificate on the root domain however. Not certain it applies to sub domains though.

 

Something is wrong with the https handshake it my reckoning.

 

 

Funnily it works in an incognito window, but give the 'This site is not secure - Continue or go back' message, continuing loads the site.

 

The domain host is 1&1 / Ionos.

 

 

Anyone run into this?   I could do with eliminating anything before I commit to buying the SSL certificates - I have a few to do.

 

 

 

Cheers in advance   

 

Edited June 18 by mikkydoos

[itskdog]

To save buying an SSL cert, see if you're able to use Let's Encrypt. You'll have to be automating certificate renewals soon anyway if you aren't already, as they're reducing the maximum lifetime for publicly-trusted web certs to 47 days in a couple of years. Only internal CAs (e.g. for your PaperCut server) can issue certs with longer times on them.

[mikkydoos]

46 minutes ago, itskdog said:

To save buying an SSL cert, see if you're able to use Let's Encrypt. You'll have to be automating certificate renewals soon anyway if you aren't already, as they're reducing the maximum lifetime for publicly-trusted web certs to 47 days in a couple of years. Only internal CAs (e.g. for your PaperCut server) can issue certs with longer times on them.

 

Can't do this with 1&1 / Ionos unfortunately.

[ZeroHour]

1 hour ago, mikkydoos said:

There is an SSL certificate on the root domain however. Not certain it applies to sub domains though.

That cert would need to be a wildcard cert to apply properly which is probably isnt. You should be able to view it in the cert properties and see if Subject Alt names has a *.domain.{tld} alias.

[Davit2005]

Use sslshopper to check the cert via the fqdn address.