I have a server that runs vsftpd to handle ftp connections. One of my users have a notebook with Total Commander and WinSCP installed. Both ftp clients fail right after the connection is established to the server and it tries to download the directory listing without any particular error message.

The weird thing is: the notebook works perfectly ok with other ftp servers. My ftp server also works well with other clients. In fact, this user also has a pc running on the same LAN as the notebook and the pc works well with the ftp server.

We use active ftp connection mode. Passive mode works well but is not an option at this point.

I would post more technical details but I don't even know what this problem is related to. Anyway, below is the server side tcpdump for the failed connection attempt. There's no further communication between the client and the server after the last line of log.

Thank you very much for any hint!

23:39:24.514852 IP 62.201.xx.xx.2241 > 195.70.xx.xx.21: S 1314489715:1314489715(0) win 65535 <mss 1460,nop,wscale 3,nop,nop,sackOK>
23:39:24.514896 IP 195.70.xx.xx.21 > 62.201.xx.xx.2241: S 2633658883:2633658883(0) ack 1314489716 win 5840 <mss 1460,nop,nop,sackOK,nop,wscale 2>
23:39:24.520842 IP 62.201.xx.xx.2241 > 195.70.xx.xx.21: . ack 1 win 62500
23:39:24.523803 IP 195.70.xx.xx.21 > 62.201.xx.xx.2241: P 1:21(20) ack 1 win 1460
23:39:24.546858 IP 62.201.xx.xx.2241 > 195.70.xx.xx.21: P 1:15(14) ack 21 win 62497
23:39:24.546902 IP 195.70.xx.xx.21 > 62.201.xx.xx.2241: . ack 15 win 1460
23:39:24.547247 IP 195.70.xx.xx.21 > 62.201.xx.xx.2241: P 21:55(34) ack 15 win 1460
23:39:24.762806 IP 62.201.xx.xx.2241 > 195.70.xx.xx.21: . ack 55 win 62493
23:39:30.415011 IP 62.201.xx.xx.2241 > 195.70.xx.xx.21: P 15:28(13) ack 55 win 62493
23:39:30.454116 IP 195.70.xx.xx.21 > 62.201.xx.xx.2241: . ack 28 win 1460
23:39:31.036283 IP 195.70.xx.xx.21 > 62.201.xx.xx.2241: P 55:78(23) ack 28 win 1460
23:39:31.053018 IP 62.201.xx.xx.2241 > 195.70.xx.xx.21: P 28:34(6) ack 78 win 62490
23:39:31.053042 IP 195.70.xx.xx.21 > 62.201.xx.xx.2241: . ack 34 win 1460
23:39:31.053268 IP 195.70.xx.xx.21 > 62.201.xx.xx.2241: P 78:97(19) ack 34 win 1460
23:39:31.068969 IP 62.201.xx.xx.2241 > 195.70.xx.xx.21: P 34:40(6) ack 97 win 62488
23:39:31.069148 IP 195.70.xx.xx.21 > 62.201.xx.xx.2241: P 97:112(15) ack 40 win 1460
23:39:31.069179 IP 195.70.xx.xx.21 > 62.201.xx.xx.2241: P 112:119(7) ack 40 win 1460
23:39:31.076981 IP 62.201.xx.xx.2241 > 195.70.xx.xx.21: . ack 119 win 62485
23:39:31.077010 IP 195.70.xx.xx.21 > 62.201.xx.xx.2241: P 119:177(58) ack 40 win 1460
23:39:31.114979 IP 62.201.xx.xx.2241 > 195.70.xx.xx.21: P 40:45(5) ack 177 win 62478
23:39:31.115164 IP 195.70.xx.xx.21 > 62.201.xx.xx.2241: P 177:186(9) ack 45 win 1460
23:39:31.180966 IP 62.201.xx.xx.2241 > 195.70.xx.xx.21: P 45:53(8) ack 186 win 62476
23:39:31.181066 IP 195.70.xx.xx.21 > 62.201.xx.xx.2241: P 186:216(30) ack 53 win 1460
23:39:31.213065 IP 62.201.xx.xx.2241 > 195.70.xx.xx.21: P 53:80(27) ack 216 win 62473
23:39:31.213180 IP 195.70.xx.xx.21 > 62.201.xx.xx.2241: P 216:267(51) ack 80 win 1460
23:39:31.251086 IP 62.201.xx.xx.2241 > 195.70.xx.xx.21: P 80:86(6) ack 267 win 62466
23:39:31.251498 IP 195.70.xx.xx.20 > 62.201.xx.xx.5001: S 2640780713:2640780713(0) win 5840 <mss 1460,sackOK,timestamp 2054371220 0,nop,wscale 2>
23:39:31.290979 IP 195.70.xx.xx.21 > 62.201.xx.xx.2241: . ack 86 win 1460
23:39:34.251489 IP 195.70.xx.xx.20 > 62.201.xx.xx.5001: S 2640780713:2640780713(0) win 5840 <mss 1460,sackOK,timestamp 2054374220 0,nop,wscale 2>
23:39:40.249625 IP 195.70.xx.xx.20 > 62.201.xx.xx.5001: S 2640780713:2640780713(0) win 5840 <mss 1460,sackOK,timestamp 2054380220 0,nop,wscale 2>
23:39:43.695108 IP 195.70.xx.xx.21 > 62.201.xx.xx.1057: P 2280716551:2280716588(37) ack 3838413728 win 5840
23:39:52.248791 IP 195.70.xx.xx.20 > 62.201.xx.xx.5001: S 2640780713:2640780713(0) win 5840 <mss 1460,sackOK,timestamp 2054392220 0,nop,wscale 2>
23:40:16.245159 IP 195.70.xx.xx.20 > 62.201.xx.xx.5001: S 2640780713:2640780713(0) win 5840 <mss 1460,sackOK,timestamp 2054416221 0,nop,wscale 2>
23:40:29.853685 IP 195.70.xx.xx.21 > 62.201.xx.xx.1057: FP 37:51(14) ack 1 win 5840
23:40:31.241951 IP 195.70.xx.xx.21 > 62.201.xx.xx.2241: P 267:304(37) ack 86 win 1460
23:40:31.381708 IP 62.201.xx.xx.2241 > 195.70.xx.xx.21: . ack 304 win 62462