It is sending sync packet all the time. If server receive it it respond like 5x back..
Good is to use iptables on whole range or
- inetnum: 138.121.245.128/25
- inetnum-up: 138.121.244.0/22 # this works better.
17:39:43.121250 IP 138.121.247.76.22746 > 10.0.5.10.443: Flags [S], seq 520937694, win 64240, options [mss 1300,nop,wscale 8,nop,nop,sackOK], length 0
17:39:46.450729 IP 138.121.247.23.38338 > 10.0.5.10.443: Flags [S], seq 3683899964, win 64240, options [mss 1300,nop,wscale 8,nop,nop,sackOK], length 0
17:39:47.204032 IP 138.121.247.31.55933 > 10.0.5.10.443: Flags [S], seq 2617483626, win 64240, options [mss 1300,nop,wscale 8,nop,nop,sackOK], length 0
17:39:49.466821 IP 138.121.245.186.48167 > 10.0.5.10.443: Flags [S], seq 2982482580, win 64240, options [mss 1300,nop,wscale 8,nop,nop,sackOK], length 0
17:39:51.027684 IP 138.121.247.28.37180 > 10.0.5.10.443: Flags [S], seq 2844211207, win 64240, options [mss 1300,nop,wscale 8,nop,nop,sackOK], length 0
17:39:51.563639 IP 138.121.247.100.55000 > 10.0.5.10.443: Flags [S], seq 1594162945, win 64240, options [mss 1300,nop,wscale 8,nop,nop,sackOK], length 0
17:39:52.355484 IP 138.121.247.217.7052 > 10.0.5.10.443: Flags [S], seq 1642631615, win 64240, options [mss 1300,nop,wscale 8,nop,nop,sackOK], length 0
17:39:53.314161 IP 138.121.247.254.5947 > 10.0.5.10.443: Flags [S], seq 2020528956, win 64240, options [mss 1300,nop,wscale 8,nop,nop,sackOK], length 0
17:39:57.438807 IP 138.121.247.252.3052 > 10.0.5.10.443: Flags [S], seq 1828198557, win 64240, options [mss 1300,nop,wscale 8,nop,nop,sackOK], length 0
17:40:02.093253 IP 138.121.245.15.33826 > 10.0.5.10.443: Flags [S], seq 1005202114, win 64240, options [mss 1300,nop,wscale 8,nop,nop,sackOK], length 0
17:40:04.365626 IP 138.121.244.248.61439 > 10.0.5.10.443: Flags [S], seq 745874737, win 64240, options [mss 1300,nop,wscale 8,nop,nop,sackOK], length 0
17:40:05.972649 IP 138.121.247.43.60682 > 10.0.5.10.443: Flags [S], seq 1125562803, win 64240, options [mss 1300,nop,wscale 8,nop,nop,sackOK], length 0
17:40:06.145221 IP 138.121.244.20.62271 > 10.0.5.10.443: Flags [S], seq 1440684666, win 64240, options [mss 1300,nop,wscale 8,nop,nop,sackOK], length 0