SharePoint Online Intranet - DNS?

[Alex Kim]

SharePoint Intranet - DNS?

I'm not sure if this is the right community to ask, and if not, can someone please direct me?

Anyways,

Background:

We are currently using a very old intranet that is hosted on one of our internal servers. I've designed a SharePoint Online intranet that looks a lot better, plus it'll feature a lot more communication and collaboration. We want to start using the new SPO intranet but the main obstacle to adoptability. 

Scenario:

When users in our organization type in, for example, gnet into their browser of choice, they are automatically redirected to http://gnet/. This provides an extreme ease of access which is great. However, if users were to access our SPO site, they'd need to login to their O365 accounts. 

Is there a way to discontinue the old gnet, use that same domain/URL and redirect them into our SharePoint Online intranet? I've looked at several solutions online and couldn't find anything concrete. The alternate access mapping feature isn't available for SPO from what i've discovered. Would anyone have any ideas?? It would be greatly appreciated.

[#2]

@Alex Kim Have you considered federating or syncing with Azure Active Directory? This would take care of the login hitch. Also, redirecting a short alias name to a SharePoint site would be easy to implement using IIS and just creating a site with a page that does a 302 redirect back to SharePoint online.

Honestly though you'll get more bang for your buck spending your time on Azure Active Directory and educate users to use portal.office.com as a launch point for all O365 applications.

[#3]

@Timothy Balk 

Thank you for your response Timothy. I'll try bringing the utilization of Azure AD into the discussion but i feel there may be some hesitation due to the fact we have just adopted OneLogin...

That point aside..

After asking this question in other discussion forums, some suggest using the CNAME method?I've tried researching some of the responses I've received and can't seem to come to a conclusion. I know CNAME involves utilizing the DNS, but I don't believe HTTP redirect does? 

Are there any pros vs. cons you're aware of?

Thanks

[#4]

@Alex Kim Use OneLogin to provide SSO into O365/Azure AD then. 

And then this:
https://www.pluralsight.com/blog/tutorials/iis7-redirect-windows-server-2008

301 or 302 Scenario -

Pro: it is pretty lightweight and shouldn't be too bad to implement potentially.

Cons: It's a server - so it needs SLA maintenance - it may also be do-able with with a firewall too.