The forwarding information base (FIB) of principals that have flat XIDs uses the default hash table available in Linux XIA. However this hash tables does not have the shrink feature. There exists a data structure known as relativistic hash table that is dynamically resizable (can expand and shrink), scalable and concurrent. This hash table, also known as rhashtable, also requires less memory per item in the table. The final aim of the project would be to augment the Linux XIA kernel with the power of relativistic programming by upgrading the FIB hash table to the relativistic hash table.