understand different UDP packet loss results: iperf3 vs nuttcp

I try to measure UDP [%packet loss] between two machines. I'm getting different results while using two different tools: 1. iperf3: machine 1: iperf3 -s machine 2: iperf3 -c -u -b0 result: [ 5] local 172.25.12.25 port 5201 connected to 172.25.12.9 port 46605 [ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams [ 5] 0.00-1.00 sec 31.2 MBytes 261 Mbits/sec 0.113 ms 566/4557 (12%) [ 5] 1.00-2.00 sec 0.00 Bytes 0.00 bits/sec 0.113 ms 0/0 (0%) [ 5] 2.00-3.00 sec 0.00 Bytes 0.00 bits/sec 0.113 ms 0/0 (0%) [ 5] 3.00-4.00 sec 0.00 Bytes 0.00 bits/sec 0.113 ms 0/0 (0%) [ 5] 4.00-5.00 sec 4.69 MBytes 39.4 Mbits/sec 0.162 ms 65056/65656 (99%) [ 5] 5.00-6.00 sec 0.00 Bytes 0.00 bits/sec 0.162 ms 0/0 (0%) [ 5] 6.00-7.00 sec 0.00 Bytes 0.00 bits/sec 0.162 ms 0/0 (0%) [ 5] 7.00-8.00 sec 0.00 Bytes 0.00 bits/sec 0.162 ms 0/0 (0%) [ 5] 8.00-9.00 sec 0.00 Bytes 0.00 bits/sec 0.162 ms 0/0 (0%) [ 5] 9.00-10.00 sec 6.20 MBytes 52.1 Mbits/sec 0.139 ms 64856/65650 (99%) [ 5] 10.00-10.25 sec 0.00 Bytes 0.00 bits/sec 0.139 ms 0/0 (0%) - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams [ 5] 0.00-10.25 sec 0.00 Bytes 0.00 bits/sec 0.139 ms 130478/135863 (96%) 2. nuttcp: machine 1: nuttcp -S machine 2: nuttcp -u -i -Ri50000m result: 83.5605 MB / 1.00 sec = 700.9434 Mbps 1581 / 87147 ~drop/pkt 1.81 ~%loss 102.1035 MB / 1.00 sec = 856.5107 Mbps 4434 / 108988 ~drop/pkt 4.07 ~%loss 108.7383 MB / 1.00 sec = 912.1637 Mbps 1651 / 112999 ~drop/pkt 1.46 ~%loss 109.0381 MB / 1.00 sec = 914.6668 Mbps 1863 / 113518 ~drop/pkt 1.64 ~%loss 108.7529 MB / 1.00 sec = 912.2939 Mbps 1534 / 112897 ~drop/pkt 1.36 ~%loss 109.3838 MB / 1.00 sec = 917.5759 Mbps 1515 / 113524 ~drop/pkt 1.33 ~%loss 107.4248 MB / 1.00 sec = 901.1491 Mbps 1337 / 111340 ~drop/pkt 1.20 ~%loss 108.1553 MB / 1.00 sec = 907.2559 Mbps 1620 / 112371 ~drop/pkt 1.44 ~%loss 110.3291 MB / 1.00 sec = 925.5187 Mbps 722 / 113699 ~drop/pkt 0.64 ~%loss I get similar bandwidth but different lost percentage. What can I do now? maybe try a third tool?