Qual é o motivo provável para o pacote TCP linux receber pacotes recebidos?

Question

Eu encontrei um problema de rede tcp que os pacotes tcp foram capturados pelo tcpdump, mas o aplicativo não consegue lê-los. a partir do arquivo pcap capturado, descobri que os pacotes são capturados (capturados no lado de recebimento, significa que os pacotes chegaram à máquina), mas não foi enviado um ack. Aconteceu de repente de cada vez, antes disso tudo está bem. Eu suspeito que esses pacotes foram descartados da camada ip para a camada tcp, mas não sei por quê. abaixo estão resumos de exibição wireshark.

"48411","2017-09-20 16:00:09.347","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250501017 Ack=3890515506 Win=46 Len=1448 TSval=1835986 TSecr=1835576"
"48412","2017-09-20 16:00:09.347","172.16.33.42","172.16.33.82","TCP","990","15664 > 15672 [PSH, ACK] Seq=4250502465 Ack=3890515506 Win=46 Len=924 TSval=1835986 TSecr=1835576"
"48413","2017-09-20 16:00:09.347","172.16.33.82","172.16.33.42","TCP","66","15672 > 15664 [ACK] Seq=3890515506 Ack=4250503389 Win=12295 Len=0 TSval=1835577 TSecr=1835986"
"48432","2017-09-20 16:00:09.350","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250503389 Ack=3890515506 Win=46 Len=1448 TSval=1835986 TSecr=1835577"
"48433","2017-09-20 16:00:09.350","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250504837 Ack=3890515506 Win=46 Len=1448 TSval=1835986 TSecr=1835577"
"48434","2017-09-20 16:00:09.350","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250506285 Ack=3890515506 Win=46 Len=1448 TSval=1835986 TSecr=1835577"
"48435","2017-09-20 16:00:09.350","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250507733 Ack=3890515506 Win=46 Len=1448 TSval=1835986 TSecr=1835577"
"48436","2017-09-20 16:00:09.350","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250509181 Ack=3890515506 Win=46 Len=1448 TSval=1835986 TSecr=1835577"
"48437","2017-09-20 16:00:09.350","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250510629 Ack=3890515506 Win=46 Len=1448 TSval=1835986 TSecr=1835577"
"48438","2017-09-20 16:00:09.350","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250512077 Ack=3890515506 Win=46 Len=1448 TSval=1835986 TSecr=1835577"
"48439","2017-09-20 16:00:09.350","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250513525 Ack=3890515506 Win=46 Len=1448 TSval=1835986 TSecr=1835577"
"48440","2017-09-20 16:00:09.350","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250514973 Ack=3890515506 Win=46 Len=1448 TSval=1835986 TSecr=1835577"
"48441","2017-09-20 16:00:09.350","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250516421 Ack=3890515506 Win=46 Len=1448 TSval=1835986 TSecr=1835577"
"48442","2017-09-20 16:00:09.350","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250517869 Ack=3890515506 Win=46 Len=1448 TSval=1835986 TSecr=1835577"
"48443","2017-09-20 16:00:09.350","172.16.33.42","172.16.33.82","TCP","990","15664 > 15672 [PSH, ACK] Seq=4250519317 Ack=3890515506 Win=46 Len=924 TSval=1835986 TSecr=1835577"
"48672","2017-09-20 16:00:09.370","172.16.33.42","172.16.33.82","TCP","150","15664 > 15672 [PSH, ACK] Seq=4250520241 Ack=3890515506 Win=46 Len=84 TSval=1835988 TSecr=1835577"
"49001","2017-09-20 16:00:09.403","172.16.33.42","172.16.33.82","TCP","386","15664 > 15672 [PSH, ACK] Seq=4250520325 Ack=3890515506 Win=46 Len=320 TSval=1835991 TSecr=1835577"
"49005","2017-09-20 16:00:09.404","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250520645 Ack=3890515506 Win=46 Len=1448 TSval=1835991 TSecr=1835577"
"49006","2017-09-20 16:00:09.404","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250522093 Ack=3890515506 Win=46 Len=1448 TSval=1835991 TSecr=1835577"
"49007","2017-09-20 16:00:09.404","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250523541 Ack=3890515506 Win=46 Len=1448 TSval=1835991 TSecr=1835577"
"49008","2017-09-20 16:00:09.404","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250524989 Ack=3890515506 Win=46 Len=1448 TSval=1835991 TSecr=1835577"
"49009","2017-09-20 16:00:09.404","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250526437 Ack=3890515506 Win=46 Len=1448 TSval=1835991 TSecr=1835577"
"49010","2017-09-20 16:00:09.404","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250527885 Ack=3890515506 Win=46 Len=1448 TSval=1835991 TSecr=1835577"
"49011","2017-09-20 16:00:09.404","172.16.33.42","172.16.33.82","TCP","1102","15664 > 15672 [PSH, ACK] Seq=4250529333 Ack=3890515506 Win=46 Len=1036 TSval=1835991 TSecr=1835577"
"49125","2017-09-20 16:00:09.415","172.16.33.42","172.16.33.82","TCP","150","15664 > 15672 [PSH, ACK] Seq=4250530369 Ack=3890515506 Win=46 Len=84 TSval=1835992 TSecr=1835577"
"49128","2017-09-20 16:00:09.418","172.16.33.42","172.16.33.82","TCP","422","15664 > 15672 [PSH, ACK] Seq=4250530453 Ack=3890515506 Win=46 Len=356 TSval=1835993 TSecr=1835577"
"49131","2017-09-20 16:00:09.418","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250530809 Ack=3890515506 Win=46 Len=1448 TSval=1835993 TSecr=1835577"
"49132","2017-09-20 16:00:09.418","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250532257 Ack=3890515506 Win=46 Len=1448 TSval=1835993 TSecr=1835577"
"49133","2017-09-20 16:00:09.418","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250533705 Ack=3890515506 Win=46 Len=1448 TSval=1835993 TSecr=1835577"
"49134","2017-09-20 16:00:09.418","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250535153 Ack=3890515506 Win=46 Len=1448 TSval=1835993 TSecr=1835577"
"49135","2017-09-20 16:00:09.418","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250536601 Ack=3890515506 Win=46 Len=1448 TSval=1835993 TSecr=1835577"
"49136","2017-09-20 16:00:09.418","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250538049 Ack=3890515506 Win=46 Len=1448 TSval=1835993 TSecr=1835577"
"49137","2017-09-20 16:00:09.419","172.16.33.42","172.16.33.82","TCP","1102","15664 > 15672 [PSH, ACK] Seq=4250539497 Ack=3890515506 Win=46 Len=1036 TSval=1835993 TSecr=1835577"
"49223","2017-09-20 16:00:09.444","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250540533 Ack=3890515506 Win=46 Len=1448 TSval=1835995 TSecr=1835577"
"49229","2017-09-20 16:00:09.444","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250541981 Ack=3890515506 Win=46 Len=1448 TSval=1835995 TSecr=1835577"
"49236","2017-09-20 16:00:09.444","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250543429 Ack=3890515506 Win=46 Len=1448 TSval=1835995 TSecr=1835577"
"49238","2017-09-20 16:00:09.445","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250544877 Ack=3890515506 Win=46 Len=1448 TSval=1835995 TSecr=1835577"
"49241","2017-09-20 16:00:09.445","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250546325 Ack=3890515506 Win=46 Len=1448 TSval=1835995 TSecr=1835577"
"49242","2017-09-20 16:00:09.445","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250547773 Ack=3890515506 Win=46 Len=1448 TSval=1835995 TSecr=1835577"
"49243","2017-09-20 16:00:09.445","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250549221 Ack=3890515506 Win=46 Len=1448 TSval=1835995 TSecr=1835577"
"49244","2017-09-20 16:00:09.445","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250550669 Ack=3890515506 Win=46 Len=1448 TSval=1835995 TSecr=1835577"
"49245","2017-09-20 16:00:09.445","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250552117 Ack=3890515506 Win=46 Len=1448 TSval=1835995 TSecr=1835577"
"49246","2017-09-20 16:00:09.445","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250553565 Ack=3890515506 Win=46 Len=1448 TSval=1835995 TSecr=1835577"
"49247","2017-09-20 16:00:09.445","172.16.33.42","172.16.33.82","TCP","1514","15664 > 15672 [ACK] Seq=4250555013 Ack=3890515506 Win=46 Len=1448 TSval=1835995 TSecr=1835577"
"49248","2017-09-20 16:00:09.445","172.16.33.42","172.16.33.82","TCP","990","15664 > 15672 [PSH, ACK] Seq=4250556461 Ack=3890515506 Win=46 Len=924 TSval=1835995 TSecr=1835577"
"50309","2017-09-20 16:00:09.560","172.16.33.42","172.16.33.82","TCP","1514","[TCP Retransmission] 15664 > 15672 [ACK] Seq=4250503389 Ack=3890515506 Win=46 Len=1448 TSval=1836007 TSecr=1835577"
"54072","2017-09-20 16:00:09.980","172.16.33.42","172.16.33.82","TCP","1514","[TCP Retransmission] 15664 > 15672 [ACK] Seq=4250503389 Ack=3890515506 Win=46 Len=1448 TSval=1836049 TSecr=1835577"
"62004","2017-09-20 16:00:10.820","172.16.33.42","172.16.33.82","TCP","1514","[TCP Retransmission] 15664 > 15672 [ACK] Seq=4250503389 Ack=3890515506 Win=46 Len=1448 TSval=1836133 TSecr=1835577"
"77298","2017-09-20 16:00:12.500","172.16.33.42","172.16.33.82","TCP","1514","[TCP Retransmission] 15664 > 15672 [ACK] Seq=4250503389 Ack=3890515506 Win=46 Len=1448 TSval=1836301 TSecr=1835577"
"108827","2017-09-20 16:00:15.860","172.16.33.42","172.16.33.82","TCP","1514","[TCP Retransmission] 15664 > 15672 [ACK] Seq=4250503389 Ack=3890515506 Win=46 Len=1448 TSval=1836637 TSecr=1835577"
"171453","2017-09-20 16:00:22.580","172.16.33.42","172.16.33.82","TCP","1514","[TCP Retransmission] 15664 > 15672 [ACK] Seq=4250503389 Ack=3890515506 Win=46 Len=1448 TSval=1837309 TSecr=1835577"