> делай tcpdump и смотри что там бегает и кто виноват.tcpdump -n -i eth0 src 212.33.12.110
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
13:27:50.516830 IP 212.33.12.110.us-cli > 10.xx.xx.xx.40466: Flags [S.], seq 2856000296, ack 1375369010, win 16384, options [mss 1452,nop,wscale 0,nop,nop,TS val 0 ecr 0,nop,nop,sackOK], length 0
13:27:50.603589 IP 212.33.12.110.us-cli > 10.xx.xx.xx.40466: Flags [P.], seq 1:1974, ack 531, win 65005, options [nop,nop,TS val 217537609 ecr 706924600], length 1973
13:27:50.688194 IP 212.33.12.110.us-cli > 10.xx.xx.xx.40466: Flags [.], ack 532, win 65005, options [nop,nop,TS val 217537609 ecr 706924771], length 0
13:27:50.688336 IP 212.33.12.110.us-cli > 10.xx.xx.xx.40466: Flags [F.], seq 1974, ack 532, win 65005, options [nop,nop,TS val 217537609 ecr 706924771], length 0
13:27:50.692585 IP 212.33.12.110.us-cli > 10.xx.xx.xx.40467: Flags [S.], seq 787889951, ack 3533935412, win 16384, options [mss 1452,nop,wscale 0,nop,nop,TS val 0 ecr 0,nop,nop,sackOK], length 0
13:27:50.779394 IP 212.33.12.110.us-cli > 10.xx.xx.xx.40467: Flags [P.], seq 1:1813, ack 999, win 64537, options [nop,nop,TS val 217537610 ecr 706924859], length 1812
13:27:50.919706 IP 212.33.12.110.us-cli > 10.xx.xx.xx.40467: Flags [.], ack 999, win 64537, options [nop,nop,TS val 217537612 ecr 706924946], length 0