A method and system to improve the operations of an integrated non-transparent bridge device (NTB) that is coupled to another NTB device or Root Port device. The integrated NTB device has logic to maintain ordering of interrupts to be sent to the remote Root Port or NTB device. The integrated NTB device allocates a contiguous portion of the memory for both the primary Base Address Register 0 associated with the integrated NTB device and the secondary BAR0 associated with the remote NTB device. The integrated NTB device has logic to report the size of the primary BAR0 as the combined size of the primary BAR0 and the size of the secondary BAR0. The integrated NTB device facilitates the dynamic modification of a mapping of each bit of a doorbell register with a respective one of a plurality of interrupt vectors based on a mapping register.