Hi Deepika,
It won't be a problem if you want to transport content between two portals having different IP address. Just create a transport package by exporting the content from source system and import it into the target system. Read the SAP help documentation provided by Simon. Follow the below wiki it will guide you with steps.
http://wiki.sdn.sap.com/wiki/display/EP/Transporting+Portal+Content
Regards,
Pradeep