If it exists, the /etc/bootptab.info file is read by the sphrdwrad command for hardware Ethernet addresses to be placed in the SDR. If it does not exist, then the sphrdwrad command still runs but takes longer to collect the information from the hardware.
Each line should list an SP node, specified by node number or frame,slot followed by a blank and the hardware Ethernet address. The file should look similar to this: