Como evitar pacotes ACK contínuos no meu servidor

Question

Eu encontrei o meu servidor tem pacotes ACK contínuos de sites diferentes, nunca pare, como abaixo (eu usei o tcpdump para capturar)

1. os sites remotos usam https.
2. contém akamai, amazon..etc, que deve ser legítimo.

Eu estou querendo saber que há conexões sem sucesso para esses sites antes, então isso aconteceu.

Eu gostaria de saber como não obter esses pacotes ACK.

23:12:37.555238 IP prg02s12-in-f1.1e100.net.https > 192.168.192.128.52285: Flags [FP.], seq 0, ack 1, win 64240, length 0
23:12:37.555242 IP 17.167.192.152.https > 192.168.192.128.49292: Flags [FP.], seq 0, ack 1, win 64239, length 0
23:12:37.555246 IP prg02s12-in-f14.1e100.net.https > 192.168.192.128.49961: Flags [FP.], seq 0:55, ack 1, win 64240, length 55
23:12:37.555253 IP 17.164.1.38.https > 192.168.192.128.49844: Flags [FP.], seq 0:37, ack 1, win 64240, length 37
23:12:37.555293 IP a2-16-84-128.deploy.akamaitechnologies.com.https > 192.168.192.128.49850: Flags [FP.], seq 0:31, ack 1, win 64240, length 31
23:12:37.555301 IP 125.209.252.12.https > 192.168.192.128.49929: Flags [FP.], seq 0, ack 1, win 64240, length 0
23:12:37.555307 IP prg02s12-in-f4.1e100.net.https > 192.168.192.128.49964: Flags [FP.], seq 0:55, ack 1, win 64240, length 55
23:12:37.655195 IP fra07s31-in-f1.1e100.net.https > 192.168.192.128.58291: Flags [FP.], seq 0, ack 1, win 64240, length 0
23:12:37.655227 IP ec2-54-193-107-210.us-west-1.compute.amazonaws.com.https > 192.168.192.128.50448: Flags [FP.], seq 0:7, ack 1, win 64240, length 7
23:12:37.655233 IP fra07s31-in-f1.1e100.net.https > 192.168.192.128.41618: Flags [FP.], seq 0:110, ack 1, win 64240, length 110
23:12:37.655238 IP ec2-54-154-38-161.eu-west-1.compute.amazonaws.com.5223 > 192.168.192.128.48941: Flags [FP.], seq 0:7, ack 1, win 64240, length 7
23:12:37.655243 IP fra07s31-in-f1.1e100.net.https > 192.168.192.128.54130: Flags [FP.], seq 0:110, ack 1, win 64240, length 110
23:12:37.655247 IP prg02s12-in-f1.1e100.net.https > 192.168.192.128.52285: Flags [FP.], seq 0, ack 1, win 64240, length 0
23:12:37.655254 IP 17.167.192.152.https > 192.168.192.128.49292: Flags [FP.], seq 0, ack 1, win 64239, length 0
23:12:37.655259 IP prg02s12-in-f14.1e100.net.https > 192.168.192.128.49961: Flags [FP.], seq 0:55, ack 1, win 64240, length 55
23:12:37.655265 IP 17.164.1.38.https > 192.168.192.128.49844: Flags [FP.], seq 0:37, ack 1, win 64240, length 37
23:12:37.655271 IP a2-16-84-128.deploy.akamaitechnologies.com.https > 192.168.192.128.49850: Flags [FP.], seq 0:31, ack 1, win 64240, length 31
23:12:37.655275 IP 125.209.252.12.https > 192.168.192.128.49929: Flags [FP.], seq 0, ack 1, win 64240, length 0
23:12:37.655281 IP prg02s12-in-f4.1e100.net.https > 192.168.192.128.49964: Flags [FP.], seq 0:55, ack 1, win 64240, length 55