In the digi document the command table says this:
MAC Mode. MAC Mode. Set/Read MAC Mode value. MAC Mode enables/disables the
use of a Digi header in the 802.15.4 RF packet. When Modes 1 or 3 are enabled
(MM=1,3), duplicate packet detection is enabled as well as certain AT commands.
The MM Command Section says this:
0 Digi Mode (802.15.4 + Digi header)
1 802.15.4 (no ACKs)
2 802.15.4 (with ACKs)
3 Digi Mode (no ACKs)
Duplicate packet detection when using ACKs
This seems at least a bit confusing, possibly contradictory. My experience is with that MM=zero and RR=1, On a broadcast, 3 broadcasts (expected) are made and detected with sniffer, but each with 'same' digi header seqno, but only 1 is passed into the buffer.
It would appear that duplicate packet detection is ON. This experience appears to contradict the table and "kind of" contradict the command section since acks are "not" being "used".