IE7 Cookie Issue when Domain Name Has Underscore "_" Character In it

Thu, 25 Sep 2008 15:53:36 Z

We recently had an issue where IE7 was dropping the authentication cookie but Firefox and other browsers worked fine. After searching the various forums and blogs it was determined that having an underscore in the domain name was causing IE7 to drop it's cookies. Very little information is out there on this and I couldn't find a MS Knowledge base article on it at all.

Removing the underscore from the web site domain name fixed the problem.

Problem: IE7 drops the authentication cookie when underscores are in the domain name.
Solution: Remove the underscore from the domain name.

Does anyone know if there is a KB article on this or that MS is making a fix for IE7 for this yet?

IE7 Cookie Issue when Domain Name Has Underscore "_" Character In it

Fri, 26 Sep 2008 04:15:52 Z

Hi,

Could you be more specific? (friendly question only)

eg. do you mean _domainname.com , domain_name.com or domainname.com/_foldername

a leading underscore is used to hid folders on a web server and only make them accessible to authenticated users.

Do you have an address where we can have a look at this (and test with IE8 also)?

Regards.

IE7 Cookie Issue when Domain Name Has Underscore "_" Character In it

Fri, 26 Sep 2008 14:32:51 Z

It was one of our internal developer sites and we changed its name so it actually works now.

It was named web_dev3.site.com.

We changed the machine name to webdev3.site.com to fix the problem. I think that you cannot make a DNS record with an underscore so it may work as designed, however I can have machine names on my internal network with underscores and Firefox works fine with it. So if you want to replicate it you may have to make an internal machine name with an underscore.

I've seen it mentioned sporadically by some other blogs. I just haven't seen a knowledge article on it.

for example

http://www.daniweb.com/forums/thread78695-3.html
http://codeigniter.com/forums/viewthread/90364/P15/#459871
http://www.microugly.com/page/blogs/internet-explorer-buglist/