Domain-related policies of the browser when passing cookies

A cookie transfer problem occurs in a specific IE6 version (2900.2180 XP SP2 GDR) recently. For this reason, refer to rfc2109.http: // tools.ietf.org/html/rfc2109

 

If Chrome/FF sends data to a. B .c.com, the cookie with domain B .c.com will not be submitted, but the cookie with. B .c.com will be submitted because the cookie that can be submitted must meet the domain-matches condition, as rfc2109 said, x.y.com domain-matches .y.com but not y.com. Therefore, this is a bug in a specific version of IE6. It submits B .c.com cookies. Rfc2109 stipulates that an explicitly specified domain must always start with a dot. Domain defaults to the request-host. (Note that there is no dot at the beginning of request-host .)

 

Why does the default value give an nonstandard domain instead of adding a point at the beginning?

 

Conclusion:

When the browser transmits a cookie, it will pass all the cookies of the current domain name and its parent domain (which must start. Sending data to a. B .c.com includes the following cookies:

A. B .c.com

. B .c.com

.C.com

If the server wants to specify the cookie domain, it should start.