Avoid sharing of same session across multiple tabs using asp.net

By default all browsers share session state between multiple tabs. So if you logged into one tab with particular site and open internal link of the same site in new tab, you need not to worry to login again. It will automatically declare you as logged in user.

When open different tabs, those tab will share same session if user access same web app in different tabs. same as sign out process also.

this is normal behavior of browser (shared single session on multiple tab).

Tab based browser – session handling

if you need each tab will get unique ID and it will looks like it is another visitor, try this code

<configuration>
  <system.web>
    <sessionState cookieless="true"
      regenerateExpiredSessionId="true" />
  </system.web>
</configuration>