Greetings,
We have FTP client written that most of the time works just fine. Once in a while (can be every day, can be every hour) program is freezing completely without any chance to come back to life.
Below is result from packet sniffer at the time when client did freeze.
First packet of interest (IMHO) is:
294 4722.880433 168.0.0.1 168.0.0.2 FTP Response: 425 Can't open data connection.
I wonder if Indy doesn't expect such behaviour of FTP server and waits for something forever. Please help, our roof is burning.
Specifics:
Delphi 7 + sp
Indy 10.0.52
FTP (NotPassive, Port 21, nothing special)
Thanks in advance,
ilya
No. Time Source Destination Protocol Info
271 3869.797625 168.0.0.2 168.0.0.1 TCP 2252 > ftp [RST, ACK] Seq=195 Ack=418 Win=0 Len=0
Frame 271 (54 bytes on wire, 54 bytes captured)
Ethernet II, Src: Dell_15:45:1a (00:14:22:15:45:1a), Dst: Cisco_39:e3:40 (00:12:da:39:e3:40)
Internet Protocol, Src: 168.0.0.2 (168.0.0.2), Dst: 168.0.0.1 (168.0.0.1)
Transmission Control Protocol, Src Port: 2252 (2252), Dst Port: ftp (21), Seq: 195, Ack: 418, Len: 0
No. Time Source Destination Protocol Info
272 4558.768269 168.0.0.2 168.0.0.1 TCP 1619 > ftp [SYN] Seq=0 Ack=0 Win=65535 Len=0 MSS=1460
Frame 272 (62 bytes on wire, 62 bytes captured)
Ethernet II, Src: Dell_15:45:1a (00:14:22:15:45:1a), Dst: Cisco_39:e3:40 (00:12:da:39:e3:40)
Internet Protocol, Src: 168.0.0.2 (168.0.0.2), Dst: 168.0.0.1 (168.0.0.1)
Transmission Control Protocol, Src Port: 1619 (1619), Dst Port: ftp (21), Seq: 0, Ack: 0, Len: 0
No. Time Source Destination Protocol Info
274 4558.819439 168.0.0.2 168.0.0.1 TCP 1619 > ftp [ACK] Seq=1 Ack=1 Win=65535 [TCP CHECKSUM INCORRECT] Len=0
Frame 274 (54 bytes on wire, 54 bytes captured)
Ethernet II, Src: Dell_15:45:1a (00:14:22:15:45:1a), Dst: Cisco_39:e3:40 (00:12:da:39:e3:40)
Internet Protocol, Src: 168.0.0.2 (168.0.0.2), Dst: 168.0.0.1 (168.0.0.1)
Transmission Control Protocol, Src Port: 1619 (1619), Dst Port: ftp (21), Seq: 1, Ack: 1, Len: 0
No. Time Source Destination Protocol Info
275 4558.870388 168.0.0.1 168.0.0.2 FTP Response: 220 Microsoft FTP Service
Frame 275 (81 bytes on wire, 81 bytes captured)
Ethernet II, Src: Cisco_39:e3:40 (00:12:da:39:e3:40), Dst: Dell_15:45:1a (00:14:22:15:45:1a)
Internet Protocol, Src: 168.0.0.1 (168.0.0.1), Dst: 168.0.0.2 (168.0.0.2)
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 1619 (1619), Seq: 1, Ack: 1, Len: 27
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
276 4558.870559 168.0.0.2 168.0.0.1 FTP Request: USER zorro
Frame 276 (78 bytes on wire, 78 bytes captured)
Ethernet II, Src: Dell_15:45:1a (00:14:22:15:45:1a), Dst: Cisco_39:e3:40 (00:12:da:39:e3:40)
Internet Protocol, Src: 168.0.0.2 (168.0.0.2), Dst: 168.0.0.1 (168.0.0.1)
Transmission Control Protocol, Src Port: 1619 (1619), Dst Port: ftp (21), Seq: 1, Ack: 28, Len: 24
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
277 4558.921588 168.0.0.1 168.0.0.2 FTP Response: 331 Password required for zorro.
Frame 277 (100 bytes on wire, 100 bytes captured)
Ethernet II, Src: Cisco_39:e3:40 (00:12:da:39:e3:40), Dst: Dell_15:45:1a (00:14:22:15:45:1a)
Internet Protocol, Src: 168.0.0.1 (168.0.0.1), Dst: 168.0.0.2 (168.0.0.2)
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 1619 (1619), Seq: 28, Ack: 25, Len: 46
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
278 4558.921742 168.0.0.2 168.0.0.1 FTP Request: PASS superb
Frame 278 (76 bytes on wire, 76 bytes captured)
Ethernet II, Src: Dell_15:45:1a (00:14:22:15:45:1a), Dst: Cisco_39:e3:40 (00:12:da:39:e3:40)
Internet Protocol, Src: 168.0.0.2 (168.0.0.2), Dst: 168.0.0.1 (168.0.0.1)
Transmission Control Protocol, Src Port: 1619 (1619), Dst Port: ftp (21), Seq: 25, Ack: 74, Len: 22
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
279 4558.973307 168.0.0.1 168.0.0.2 FTP Response: 230 User zorro logged in.
Frame 279 (93 bytes on wire, 93 bytes captured)
Ethernet II, Src: Cisco_39:e3:40 (00:12:da:39:e3:40), Dst: Dell_15:45:1a (00:14:22:15:45:1a)
Internet Protocol, Src: 168.0.0.1 (168.0.0.1), Dst: 168.0.0.2 (168.0.0.2)
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 1619 (1619), Seq: 74, Ack: 47, Len: 39
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
280 4558.973474 168.0.0.2 168.0.0.1 FTP Request: FEAT
Frame 280 (60 bytes on wire, 60 bytes captured)
Ethernet II, Src: Dell_15:45:1a (00:14:22:15:45:1a), Dst: Cisco_39:e3:40 (00:12:da:39:e3:40)
Internet Protocol, Src: 168.0.0.2 (168.0.0.2), Dst: 168.0.0.1 (168.0.0.1)
Transmission Control Protocol, Src Port: 1619 (1619), Dst Port: ftp (21), Seq: 47, Ack: 113, Len: 6
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
281 4559.024250 168.0.0.1 168.0.0.2 FTP Response: 211-FEAT
Frame 281 (64 bytes on wire, 64 bytes captured)
Ethernet II, Src: Cisco_39:e3:40 (00:12:da:39:e3:40), Dst: Dell_15:45:1a (00:14:22:15:45:1a)
Internet Protocol, Src: 168.0.0.1 (168.0.0.1), Dst: 168.0.0.2 (168.0.0.2)
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 1619 (1619), Seq: 113, Ack: 53, Len: 10
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
282 4559.177767 168.0.0.2 168.0.0.1 TCP 1619 > ftp [ACK] Seq=53 Ack=123 Win=65413 [TCP CHECKSUM INCORRECT] Len=0
Frame 282 (54 bytes on wire, 54 bytes captured)
Ethernet II, Src: Dell_15:45:1a (00:14:22:15:45:1a), Dst: Cisco_39:e3:40 (00:12:da:39:e3:40)
Internet Protocol, Src: 168.0.0.2 (168.0.0.2), Dst: 168.0.0.1 (168.0.0.1)
Transmission Control Protocol, Src Port: 1619 (1619), Dst Port: ftp (21), Seq: 53, Ack: 123, Len: 0
No. Time Source Destination Protocol Info
283 4559.228692 168.0.0.1 168.0.0.2 FTP Response: SIZE
Frame 283 (83 bytes on wire, 83 bytes captured)
Ethernet II, Src: Cisco_39:e3:40 (00:12:da:39:e3:40), Dst: Dell_15:45:1a (00:14:22:15:45:1a)
Internet Protocol, Src: 168.0.0.1 (168.0.0.1), Dst: 168.0.0.2 (168.0.0.2)
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 1619 (1619), Seq: 123, Ack: 53, Len: 29
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
284 4559.228914 168.0.0.2 168.0.0.1 FTP Request: TYPE I
Frame 284 (62 bytes on wire, 62 bytes captured)
Ethernet II, Src: Dell_15:45:1a (00:14:22:15:45:1a), Dst: Cisco_39:e3:40 (00:12:da:39:e3:40)
Internet Protocol, Src: 168.0.0.2 (168.0.0.2), Dst: 168.0.0.1 (168.0.0.1)
Transmission Control Protocol, Src Port: 1619 (1619), Dst Port: ftp (21), Seq: 53, Ack: 152, Len: 8
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
285 4559.279718 168.0.0.1 168.0.0.2 FTP Response: 200 Type set to I.
Frame 285 (74 bytes on wire, 74 bytes captured)
Ethernet II, Src: Cisco_39:e3:40 (00:12:da:39:e3:40), Dst: Dell_15:45:1a (00:14:22:15:45:1a)
Internet Protocol, Src: 168.0.0.1 (168.0.0.1), Dst: 168.0.0.2 (168.0.0.2)
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 1619 (1619), Seq: 152, Ack: 61, Len: 20
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
287 4559.330846 168.0.0.1 168.0.0.2 FTP Response: 215 Windows_NT
Frame 287 (70 bytes on wire, 70 bytes captured)
Ethernet II, Src: Cisco_39:e3:40 (00:12:da:39:e3:40), Dst: Dell_15:45:1a (00:14:22:15:45:1a)
Internet Protocol, Src: 168.0.0.1 (168.0.0.1), Dst: 168.0.0.2 (168.0.0.2)
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 1619 (1619), Seq: 172, Ack: 67, Len: 16
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
288 4559.334005 168.0.0.2 168.0.0.1 FTP Request: PORT 172,16,251,14,6,94
Frame 288 (79 bytes on wire, 79 bytes captured)
Ethernet II, Src: Dell_15:45:1a (00:14:22:15:45:1a), Dst: Cisco_39:e3:40 (00:12:da:39:e3:40)
Internet Protocol, Src: 168.0.0.2 (168.0.0.2), Dst: 168.0.0.1 (168.0.0.1)
Transmission Control Protocol, Src Port: 1619 (1619), Dst Port: ftp (21), Seq: 67, Ack: 188, Len: 25
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
289 4559.385081 168.0.0.1 168.0.0.2 FTP Response: 200 PORT command successful.
Frame 289 (84 bytes on wire, 84 bytes captured)
Ethernet II, Src: Cisco_39:e3:40 (00:12:da:39:e3:40), Dst: Dell_15:45:1a (00:14:22:15:45:1a)
Internet Protocol, Src: 168.0.0.1 (168.0.0.1), Dst: 168.0.0.2 (168.0.0.2)
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 1619 (1619), Seq: 188, Ack: 92, Len: 30
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
290 4559.385253 168.0.0.2 168.0.0.1 FTP Request: STOR file.zip
Frame 290 (85 bytes on wire, 85 bytes captured)
Ethernet II, Src: Dell_15:45:1a (00:14:22:15:45:1a), Dst: Cisco_39:e3:40 (00:12:da:39:e3:40)
Internet Protocol, Src: 168.0.0.2 (168.0.0.2), Dst: 168.0.0.1 (168.0.0.1)
Transmission Control Protocol, Src Port: 1619 (1619), Dst Port: ftp (21), Seq: 92, Ack: 218, Len: 31
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
291 4559.587707 168.0.0.1 168.0.0.2 TCP ftp > 1619 [ACK] Seq=218 Ack=123 Win=65413 Len=0
Frame 291 (60 bytes on wire, 60 bytes captured)
Ethernet II, Src: Cisco_39:e3:40 (00:12:da:39:e3:40), Dst: Dell_15:45:1a (00:14:22:15:45:1a)
Internet Protocol, Src: 168.0.0.1 (168.0.0.1), Dst: 168.0.0.2 (168.0.0.2)
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 1619 (1619), Seq: 218, Ack: 123, Len: 0
No. Time Source Destination Protocol Info
292 4701.887446 168.0.0.1 168.0.0.2 FTP Response: 150 Opening BINARY mode data connection for file.zip.
Frame 292 (125 bytes on wire, 125 bytes captured)
Ethernet II, Src: Cisco_39:e3:40 (00:12:da:39:e3:40), Dst: Dell_15:45:1a (00:14:22:15:45:1a)
Internet Protocol, Src: 168.0.0.1 (168.0.0.1), Dst: 168.0.0.2 (168.0.0.2)
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 1619 (1619), Seq: 218, Ack: 123, Len: 71
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
293 4702.016047 168.0.0.2 168.0.0.1 TCP 1619 > ftp [ACK] Seq=123 Ack=289 Win=65247 [TCP CHECKSUM INCORRECT] Len=0
Frame 293 (54 bytes on wire, 54 bytes captured)
Ethernet II, Src: Dell_15:45:1a (00:14:22:15:45:1a), Dst: Cisco_39:e3:40 (00:12:da:39:e3:40)
Internet Protocol, Src: 168.0.0.2 (168.0.0.2), Dst: 168.0.0.1 (168.0.0.1)
Transmission Control Protocol, Src Port: 1619 (1619), Dst Port: ftp (21), Seq: 123, Ack: 289, Len: 0
No. Time Source Destination Protocol Info
294 4722.880433 168.0.0.1 168.0.0.2 FTP Response: 425 Can't open data connection.
Frame 294 (87 bytes on wire, 87 bytes captured)
Ethernet II, Src: Cisco_39:e3:40 (00:12:da:39:e3:40), Dst: Dell_15:45:1a (00:14:22:15:45:1a)
Internet Protocol, Src: 168.0.0.1 (168.0.0.1), Dst: 168.0.0.2 (168.0.0.2)
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 1619 (1619), Seq: 289, Ack: 123, Len: 33
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
296 4885.813925 168.0.0.1 168.0.0.2 FTP Response: 421 Timeout (120 seconds): closing control connection.
Frame 296 (110 bytes on wire, 110 bytes captured)
Ethernet II, Src: Cisco_39:e3:40 (00:12:da:39:e3:40), Dst: Dell_15:45:1a (00:14:22:15:45:1a)
Internet Protocol, Src: 168.0.0.1 (168.0.0.1), Dst: 168.0.0.2 (168.0.0.2)
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 1619 (1619), Seq: 322, Ack: 123, Len: 56
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
297 4885.977937 168.0.0.2 168.0.0.1 TCP 1619 > ftp [ACK] Seq=123 Ack=378 Win=65158 [TCP CHECKSUM INCORRECT] Len=0
Frame 297 (54 bytes on wire, 54 bytes captured)
Ethernet II, Src: Dell_15:45:1a (00:14:22:15:45:1a), Dst: Cisco_39:e3:40 (00:12:da:39:e3:40)
Internet Protocol, Src: 168.0.0.2 (168.0.0.2), Dst: 168.0.0.1 (168.0.0.1)
Transmission Control Protocol, Src Port: 1619 (1619), Dst Port: ftp (21), Seq: 123, Ack: 378, Len: 0
No. Time Source Destination Protocol Info
298 4887.047640 168.0.0.1 168.0.0.2 FTP Response: 421 Terminating connection.
Frame 298 (83 bytes on wire, 83 bytes captured)
Ethernet II, Src: Cisco_39:e3:40 (00:12:da:39:e3:40), Dst: Dell_15:45:1a (00:14:22:15:45:1a)
Internet Protocol, Src: 168.0.0.1 (168.0.0.1), Dst: 168.0.0.2 (168.0.0.2)
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 1619 (1619), Seq: 378, Ack: 123, Len: 29
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
299 4887.047671 168.0.0.2 168.0.0.1 TCP 1619 > ftp [ACK] Seq=123 Ack=408 Win=65129 [TCP CHECKSUM INCORRECT] Len=0
Frame 299 (54 bytes on wire, 54 bytes captured)
Ethernet II, Src: Dell_15:45:1a (00:14:22:15:45:1a), Dst: Cisco_39:e3:40 (00:12:da:39:e3:40)
Internet Protocol, Src: 168.0.0.2 (168.0.0.2), Dst: 168.0.0.1 (168.0.0.1)
Transmission Control Protocol, Src Port: 1619 (1619), Dst Port: ftp (21), Seq: 123, Ack: 408, Len: 0
No. Time Source Destination Protocol Info
300 4957.534035 168.0.0.2 168.0.0.1 TCP 3368 > ftp [SYN] Seq=0 Ack=0 Win=65535 Len=0 MSS=1460
Frame 300 (62 bytes on wire, 62 bytes captured)
Ethernet II, Src: Dell_15:45:1a (00:14:22:15:45:1a), Dst: Cisco_39:e3:40 (00:12:da:39:e3:40)
Internet Protocol, Src: 168.0.0.2 (168.0.0.2), Dst: 168.0.0.1 (168.0.0.1)
Transmission Control Protocol, Src Port: 3368 (3368), Dst Port: ftp (21), Seq: 0, Ack: 0, Len: 0
No. Time Source Destination Protocol Info
301 4957.585002 168.0.0.1 168.0.0.2 TCP ftp > 3368 [SYN, ACK] Seq=0 Ack=1 Win=16384 Len=0 MSS=1380
Frame 301 (62 bytes on wire, 62 bytes captured)
Ethernet II, Src: Cisco_39:e3:40 (00:12:da:39:e3:40), Dst: Dell_15:45:1a (00:14:22:15:45:1a)
Internet Protocol, Src: 168.0.0.1 (168.0.0.1), Dst: 168.0.0.2 (168.0.0.2)
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 3368 (3368), Seq: 0, Ack: 1, Len: 0
No. Time Source Destination Protocol Info
302 4957.585030 168.0.0.2 168.0.0.1 TCP 3368 > ftp [ACK] Seq=1 Ack=1 Win=65535 [TCP CHECKSUM INCORRECT] Len=0
Frame 302 (54 bytes on wire, 54 bytes captured)
Ethernet II, Src: Dell_15:45:1a (00:14:22:15:45:1a), Dst: Cisco_39:e3:40 (00:12:da:39:e3:40)
Internet Protocol, Src: 168.0.0.2 (168.0.0.2), Dst: 168.0.0.1 (168.0.0.1)
Transmission Control Protocol, Src Port: 3368 (3368), Dst Port: ftp (21), Seq: 1, Ack: 1, Len: 0
No. Time Source Destination Protocol Info
303 4957.635910 168.0.0.1 168.0.0.2 FTP Response: 220 Microsoft FTP Service
Frame 303 (81 bytes on wire, 81 bytes captured)
Ethernet II, Src: Cisco_39:e3:40 (00:12:da:39:e3:40), Dst: Dell_15:45:1a (00:14:22:15:45:1a)
Internet Protocol, Src: 168.0.0.1 (168.0.0.1), Dst: 168.0.0.2 (168.0.0.2)
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 3368 (3368), Seq: 1, Ack: 1, Len: 27
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
304 4957.636089 168.0.0.2 168.0.0.1 FTP Request: USER zorro
Frame 304 (78 bytes on wire, 78 bytes captured)
Ethernet II, Src: Dell_15:45:1a (00:14:22:15:45:1a), Dst: Cisco_39:e3:40 (00:12:da:39:e3:40)
Internet Protocol, Src: 168.0.0.2 (168.0.0.2), Dst: 168.0.0.1 (168.0.0.1)
Transmission Control Protocol, Src Port: 3368 (3368), Dst Port: ftp (21), Seq: 1, Ack: 28, Len: 24
File Transfer Protocol (FTP)
No. Time Source Destination Protocol Info
305 4957.686972 168.0.0.1 168.0.0.2 FTP Response: 331 Password required for zorro.
Frame 305 (100 bytes on wire, 100 bytes captured)
Ethernet II, Src: Cisco_39:e3:40 (00:12:da:39:e3:40), Dst: Dell_15:45:1a (00:14:22:15:45:1a)
Internet Protocol, Src: 168.0.0.1 (168.0.0.1), Dst: 168.0.0.2 (168.0.0.2)
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 3368 (3368), Seq: 28, Ack: 25, Len: 46
File Transfer Protocol (FTP)
