Bing and lack of SNI support
I have been emailing with Bing support for several weeks now and as of today, they started to offer limited support for SNI.
I made clear to them that the issue was 100% sure in their lack of SNI support by moving one of my websites to a dedicated IPv4 and turning off SNI for that address. After that, the sitemap got succesfully verified by Bing. All other HTTPS websites/sitemaps that are on the same server, but on the shared IPv4 address, were not indexed. Seems like they finally started implementing SNI!
We highly appreciate your patience as we review this matter together with our Product Group. My name is Jenny and I will be providing you with the status of this Service Request.
We would like to inform you that as of today, Bing only supports a limited number of SNI websites through a whitelist. We understand that more and more websites are switching to SNI so we plan to expand our support for all SNI hosts in the next 6 months.
As a short term mitigation, we can whitelist about 10 - 20 SNI hosts for you, if needed.
So if you would like to have your SNI website added to the whitelist, I'd recommend sending Bing Support an email so that your SNI websites will be succesfully indexed.
I'm using a single certificate for multiple domain names using the "certificate subject alt name" feature. Bing does understand this type of certificate. I just tested it using "fetch as bingbot".
This would be another possible solution for you. You need to generate a single certificate with all your domain names in it. Because it is a single certificate it is all hosted with a single IP address.
The disadvantages are:
- All your domains are linked by the certificate.
- If you want to add a domain name you need to generate a new certificate and install it.
I'm using https://startssl.com/ as my certificate authority for this.