Found it...

[leeoz]

Re: Using NRF24 - How can I limit the max auto NodeID number?

#define BROADCAST_ADDRESS ((uint8_t)255) //!< broadcasts are addressed to ID 255
#define DISTANCE_INVALID ((uint8_t)255) //!< invalid distance when searching for parent
#define MAX_HOPS ((uint8_t)254) //!< maximal mumber of hops for ping/pong
#define INVALID_HOPS ((uint8_t)255) //!< invalid hops
#define MAX_SUBSEQ_MSGS 5 //!< Maximum number of subsequentially processed messages in FIFO (to prevent transport deadlock if HW issue)
#define CHKUPL_INTERVAL ((uint32_t)10000) //!< Minimum time interval to re-check uplink

in MyTransport.h

now which one do I change to 100, so my radio system will be limited to nodes 0-100???