Does this related issue belong to cross-domain related issues? How to solve it

Is this question a cross-domain issue? How do I fix it?
For example there is a PHP Web site with an IP address of 222.1.2.3 Domain name is www.abc.com in the site root directory has one or two level directory Dir2

Now you need to use IP to access this site, log in and save the session variable. Then access the level two directory through a domain name
Www.abc.com/dir2 The following page, the request if the IP access under the login, under the domain name access is also logged in status.
Is this question a cross-domain issue? How do I fix it?
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I don't think it is. I do not know what other small partners will be thinking.
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You can do it yourself, you know?
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Why not unify, change to change.
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IP and domain names are cross-domain
LocalHost and 127.0.0.1 are cross-domain.
The demand is a bit strange, the domain name and IP why should separate use?
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The same machine is not cross-domain.
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This situation can be considered with cooikes.

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