I have SharePoint Server 2010, and WebApp with site collection http://aa.contoso.com when i add IIS Site Binding http://bb.contoso.com and HH in DNS but Without adding Alternate Access Mapping and the result is "i can browse bb.contoso.com" but can NOT edit the site contents. it happen without having SP Alternate Access Mapping. I think it should not work that way. anyone has explaination?
If you would like your SharePoint web application and Site Collection to respond correctly, you should extend the web application and use alternate access mapping.