Comment 6 for bug 1822256

Yang Li (yang-li) wrote :

I reproduced this bug again, in the server side, I got these packets, there are 'seq 157061839:157068829' and 'seq 157061839:157063237' both exist which start with 157061839, this is unnormal.
16:11:36.795490 fa:16:3e:7b:31:8b > fa:16:3e:7e:e8:5b, ethertype IPv4 (0x0800), length 1312: 192.168.100.19.22 > 192.168.100.5.54367: Flags [P.], seq 157060593:157061839, ack 737639, win 2016, options [nop,nop,TS val 69340450 ecr 69335583], length 1246
16:11:36.796120 fa:16:3e:7b:31:8b > fa:16:3e:7e:e8:5b, ethertype IPv4 (0x0800), length 7056: 192.168.100.19.22 > 192.168.100.5.54367: Flags [.], seq 157061839:157068829, ack 737683, win 2016, options [nop,nop,TS val 69340450 ecr 69335583], length 6990
16:11:36.796153 fa:16:3e:7b:31:8b > fa:16:3e:7e:e8:5b, ethertype IPv4 (0x0800), length 1312: 192.168.100.19.22 > 192.168.100.5.54367: Flags [P.], seq 157068829:157070075, ack 737683, win 2016, options [nop,nop,TS val 69340450 ecr 69335583], length 1246
16:11:36.998982 fa:16:3e:7b:31:8b > fa:16:3e:7e:e8:5b, ethertype IPv4 (0x0800), length 1464: 192.168.100.19.22 > 192.168.100.5.54367: Flags [.], seq 157061839:157063237, ack 737683, win 2016, options [nop,nop,TS val 69340501 ecr 69335583], length 1398
16:11:37.407022 fa:16:3e:7b:31:8b > fa:16:3e:7e:e8:5b, ethertype IPv4 (0x0800), length 1464: 192.168.100.19.22 > 192.168.100.5.54367: Flags [.], seq 157061839:157063237, ack 737683, win 2016, options [nop,nop,TS val 69340603 ecr 69335583], length 1398
16:11:38.222904 fa:16:3e:7b:31:8b > fa:16:3e:7e:e8:5b, ethertype IPv4 (0x0800), length 1464: 192.168.100.19.22 > 192.168.100.5.54367: Flags [.], seq 157061839:157063237, ack 737683, win 2016, options [nop,nop,TS val 69340807 ecr 69335583], length 1398

In the client side, I got these packets, which contain 'sack 1 {157061839:157063237}', I think the sack option caused retransmission.
16:09:54.527451 fa:16:3e:7e:e8:5b > fa:16:3e:7b:31:8b, ethertype IPv4 (0x0800), length 78: 192.168.100.5.54367 > 192.168.100.19.22: Flags [.], ack 157070075, win 18486, options [nop,nop,TS val 69335634 ecr 69340450,nop,nop,sack 1 {157061839:157063237}], length 0
16:09:54.935973 fa:16:3e:7e:e8:5b > fa:16:3e:7b:31:8b, ethertype IPv4 (0x0800), length 78: 192.168.100.5.54367 > 192.168.100.19.22: Flags [.], ack 157070075, win 18486, options [nop,nop,TS val 69335736 ecr 69340450,nop,nop,sack 1 {157061839:157063237}], length 0
16:09:55.751463 fa:16:3e:7e:e8:5b > fa:16:3e:7b:31:8b, ethertype IPv4 (0x0800), length 78: 192.168.100.5.54367 > 192.168.100.19.22: Flags [.], ack 157070075, win 18486, options [nop,nop,TS val 69335940 ecr 69340450,nop,nop,sack 1 {157061839:157063237}], length 0