Обновите ISP, сказал, что они недавно добавили область, где этот компьютер расположен к их сети IPv6. По совпадению начиная со дня они добавили, что область к их сети IPv6, никакое соединение FTP не было возможно.
ISP смог задержать это определенное соединение с IPv4 (для ограниченного количества времени) и... FTP работал снова.
Исходное описание проблемы
У меня есть проблема уровня TCP между клиентами FTP и FTP-серверами (я думаю, что это - про-FTP-сервер, но я не уверен).
После запроса режима PASV для передачи данных клиент получает ACK, но не получает 227 entering passive mode
сообщение. Клиент ожидает в течение 30 секунд, прежде чем это отправит a TYPE A request
который сервер пробует к ACK, но с несправедливостью число SEQ.
Число SEQ содержит размер Enter passive mode
сообщение. Сервер также отправляет a 200 Switching to ASCII mode
который также имеет несправедливость число SEQ.
Оттуда это - 7 попыток Повторной передачи TCP и TCP DUP ACK, в то время как обе стороны используют 'свои' числа SEQ. (Разве неподтвержденное не должно передавать это сервер, отправленный ретранслироваться? Значение, не был должен сервер, просто отправленный 227 entering passive mode
обмениваться сообщениями снова? Или, по крайней мере, зафиксируйте число SEQ?)
Я получил несколько вопросов здесь. Для одного, какая сторона ведет себя неправильно здесь? Одна сторона должна зафиксировать, это - число SEQ, но кто? И как определенное может обмениваться сообщениями (это всегда Entering passive mode
сообщение), всегда теряются?
Для создания вопросов более странными, это происходит только на одном компьютере. Из сотен. И это также только происходит с одним FTP-сервером. (которым я не управляю). Сервер и рассматриваемый компьютер подключены через Интернет.
Журналы были получены через маршрутизатор клиента, таким образом, это не проблема с ПК.
Хорошо, мне удалось отфильтровать протокол. Таким образом, здесь это:
No. Time Protocol Length Info
39 5.988043 FTP 68 Request: PASV
Frame 39: 68 bytes on wire (544 bits), 68 bytes captured (544 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 68, Ack: 294, Len: 6
File Transfer Protocol (FTP)
No. Time Protocol Length Info
40 6.034184 TCP 62 ftp > 49736 [ACK] Seq=294 Ack=74 Win=32695 Len=0
Frame 40: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 294, Ack: 74, Len: 0
No. Time Protocol Length Info
41 36.381924 FTP 70 Request: TYPE A
Frame 41: 70 bytes on wire (560 bits), 70 bytes captured (560 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 74, Ack: 294, Len: 8
File Transfer Protocol (FTP)
No. Time Protocol Length Info
42 36.417678 TCP 62 [TCP Previous segment lost] ftp > 49736 [ACK] Seq=345 Ack=82 Win=32687 Len=0
Frame 42: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 345, Ack: 82, Len: 0
No. Time Protocol Length Info
43 36.435735 FTP 92 Response: 200 Switching to ASCII mode.
Frame 43: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 345, Ack: 82, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
44 36.436237 TCP 62 [TCP Dup ACK 41#1] 49736 > ftp [ACK] Seq=82 Ack=294 Win=65047 Len=0
Frame 44: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 82, Ack: 294, Len: 0
No. Time Protocol Length Info
45 37.274734 FTP 92 [TCP Retransmission] Response: 200 Switching to ASCII mode.
Frame 45: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 345, Ack: 82, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
46 37.275388 TCP 62 [TCP Dup ACK 41#2] 49736 > ftp [ACK] Seq=82 Ack=294 Win=65047 Len=0
Frame 46: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 82, Ack: 294, Len: 0
No. Time Protocol Length Info
47 38.515559 FTP 92 [TCP Retransmission] Response: 200 Switching to ASCII mode.
Frame 47: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 345, Ack: 82, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
48 38.516182 TCP 62 [TCP Dup ACK 41#3] 49736 > ftp [ACK] Seq=82 Ack=294 Win=65047 Len=0
Frame 48: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 82, Ack: 294, Len: 0
No. Time Protocol Length Info
49 40.376003 FTP 92 [TCP Retransmission] Response: 200 Switching to ASCII mode.
Frame 49: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 345, Ack: 82, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
50 40.376567 TCP 62 [TCP Dup ACK 41#4] 49736 > ftp [ACK] Seq=82 Ack=294 Win=65047 Len=0
Frame 50: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 82, Ack: 294, Len: 0
No. Time Protocol Length Info
51 43.474007 FTP 92 [TCP Retransmission] Response: 200 Switching to ASCII mode.
Frame 51: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 345, Ack: 82, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
52 43.474611 TCP 62 [TCP Dup ACK 41#5] 49736 > ftp [ACK] Seq=82 Ack=294 Win=65047 Len=0
Frame 52: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 82, Ack: 294, Len: 0
No. Time Protocol Length Info
53 49.053924 FTP 92 [TCP Retransmission] Response: 200 Switching to ASCII mode.
Frame 53: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 345, Ack: 82, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
54 49.054515 TCP 62 [TCP Dup ACK 41#6] 49736 > ftp [ACK] Seq=82 Ack=294 Win=65047 Len=0
Frame 54: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 82, Ack: 294, Len: 0
No. Time Protocol Length Info
55 59.593195 FTP 92 [TCP Retransmission] Response: 200 Switching to ASCII mode.
Frame 55: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 345, Ack: 82, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
56 59.593832 TCP 62 [TCP Dup ACK 41#7] 49736 > ftp [ACK] Seq=82 Ack=294 Win=65047 Len=0
Frame 56: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 82, Ack: 294, Len: 0
No. Time Protocol Length Info
57 66.796925 FTP 70 Request: TYPE A
Frame 57: 70 bytes on wire (560 bits), 70 bytes captured (560 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 82, Ack: 294, Len: 8
File Transfer Protocol (FTP)
No. Time Protocol Length Info
58 66.833363 TCP 62 ftp > 49736 [ACK] Seq=375 Ack=90 Win=32679 Len=0
Frame 58: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 375, Ack: 90, Len: 0
No. Time Protocol Length Info
59 66.852889 FTP 92 Response: 200 Switching to ASCII mode.
Frame 59: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 375, Ack: 90, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
60 66.853447 TCP 62 [TCP Dup ACK 57#1] 49736 > ftp [ACK] Seq=90 Ack=294 Win=65047 Len=0
Frame 60: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 90, Ack: 294, Len: 0
No. Time Protocol Length Info
61 67.653089 FTP 92 [TCP Retransmission] Response: 200 Switching to ASCII mode.
Frame 61: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 375, Ack: 90, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
62 67.653593 TCP 62 [TCP Dup ACK 57#2] 49736 > ftp [ACK] Seq=90 Ack=294 Win=65047 Len=0
Frame 62: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 90, Ack: 294, Len: 0
No. Time Protocol Length Info
63 68.894847 FTP 92 [TCP Retransmission] Response: 200 Switching to ASCII mode.
Frame 63: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 375, Ack: 90, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
64 68.895352 TCP 62 [TCP Dup ACK 57#3] 49736 > ftp [ACK] Seq=90 Ack=294 Win=65047 Len=0
Frame 64: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 90, Ack: 294, Len: 0
No. Time Protocol Length Info
65 70.755267 FTP 92 [TCP Retransmission] Response: 200 Switching to ASCII mode.
Frame 65: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 375, Ack: 90, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
66 70.755790 TCP 62 [TCP Dup ACK 57#4] 49736 > ftp [ACK] Seq=90 Ack=294 Win=65047 Len=0
Frame 66: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 90, Ack: 294, Len: 0
No. Time Protocol Length Info
67 73.851892 FTP 92 [TCP Retransmission] Response: 200 Switching to ASCII mode.
Frame 67: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 375, Ack: 90, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
68 73.852389 TCP 62 [TCP Dup ACK 57#5] 49736 > ftp [ACK] Seq=90 Ack=294 Win=65047 Len=0
Frame 68: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 90, Ack: 294, Len: 0
No. Time Protocol Length Info
69 79.432036 FTP 92 [TCP Retransmission] Response: 200 Switching to ASCII mode.
Frame 69: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 375, Ack: 90, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
70 79.432625 TCP 62 [TCP Dup ACK 57#6] 49736 > ftp [ACK] Seq=90 Ack=294 Win=65047 Len=0
Frame 70: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 90, Ack: 294, Len: 0
No. Time Protocol Length Info
71 87.075370 FTP 70 Request: TYPE A
Frame 71: 70 bytes on wire (560 bits), 70 bytes captured (560 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 90, Ack: 294, Len: 8
File Transfer Protocol (FTP)
No. Time Protocol Length Info
72 87.111901 TCP 62 ftp > 49736 [ACK] Seq=405 Ack=98 Win=32671 Len=0
Frame 72: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 405, Ack: 98, Len: 0
No. Time Protocol Length Info
73 87.131366 FTP 92 Response: 200 Switching to ASCII mode.
Frame 73: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 405, Ack: 98, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
74 87.131840 TCP 62 [TCP Dup ACK 71#1] 49736 > ftp [ACK] Seq=98 Ack=294 Win=65047 Len=0
Frame 74: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 98, Ack: 294, Len: 0
No. Time Protocol Length Info
75 87.801062 FTP 92 [TCP Retransmission] Response: 200 Switching to ASCII mode.
Frame 75: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 405, Ack: 98, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
76 87.801573 TCP 62 [TCP Dup ACK 71#2] 49736 > ftp [ACK] Seq=98 Ack=294 Win=65047 Len=0
Frame 76: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 98, Ack: 294, Len: 0
No. Time Protocol Length Info
77 89.041426 FTP 92 [TCP Retransmission] Response: 200 Switching to ASCII mode.
Frame 77: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 405, Ack: 98, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
78 89.042081 TCP 62 [TCP Dup ACK 71#3] 49736 > ftp [ACK] Seq=98 Ack=294 Win=65047 Len=0
Frame 78: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 98, Ack: 294, Len: 0
No. Time Protocol Length Info
79 90.901416 FTP 92 [TCP Retransmission] Response: 200 Switching to ASCII mode.
Frame 79: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 405, Ack: 98, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
80 90.901988 TCP 62 [TCP Dup ACK 71#4] 49736 > ftp [ACK] Seq=98 Ack=294 Win=65047 Len=0
Frame 80: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 98, Ack: 294, Len: 0
No. Time Protocol Length Info
81 94.000587 FTP 92 [TCP Retransmission] Response: 200 Switching to ASCII mode.
Frame 81: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 405, Ack: 98, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
82 94.001269 TCP 62 [TCP Dup ACK 71#5] 49736 > ftp [ACK] Seq=98 Ack=294 Win=65047 Len=0
Frame 82: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 98, Ack: 294, Len: 0
No. Time Protocol Length Info
83 99.580475 FTP 92 [TCP Retransmission] Response: 200 Switching to ASCII mode.
Frame 83: 92 bytes on wire (736 bits), 92 bytes captured (736 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 405, Ack: 98, Len: 30
File Transfer Protocol (FTP)
No. Time Protocol Length Info
84 99.581110 TCP 62 [TCP Dup ACK 71#6] 49736 > ftp [ACK] Seq=98 Ack=294 Win=65047 Len=0
Frame 84: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 98, Ack: 294, Len: 0
No. Time Protocol Length Info
85 117.494304 FTP 70 Request: TYPE A
Frame 85: 70 bytes on wire (560 bits), 70 bytes captured (560 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: 49736 (49736), Dst Port: ftp (21), Seq: 98, Ack: 294, Len: 8
File Transfer Protocol (FTP)
No. Time Protocol Length Info
86 117.531119 TCP 62 ftp > 49736 [RST] Seq=294 Win=0 Len=0
Frame 86: 62 bytes on wire (496 bits), 62 bytes captured (496 bits)
Ethernet II
PPP-over-Ethernet Session
Point-to-Point Protocol
Internet Protocol Version 4
Transmission Control Protocol, Src Port: ftp (21), Dst Port: 49736 (49736), Seq: 294, Len: 0
править
Я сверился с другим FTP-сервером, который находится под моим контролем и get's материала, странный теперь (чтение: это не работает с тот одним ни один). Согласно моему серверу, это общается с адресом IPv4, заканчивающимся на .0
. Для записи я расположен в Германии. Я никогда не видел, что адрес IPv4 заканчивается на .0
прежде.
Если я проверяю маршрутизатор на стороне клиента, это сообщает о совершенно другом общедоступном адресе IPv4 (по крайней мере, что каждый выглядит допустимым), и это также сообщает об адресе IPv6 (чрезвычайно редко в Германии, чтобы иметь ту. Зависит от ISP.)
И журналы моего сервера говорят, что это отправляет (и также ретранслирует, поскольку это не добирается ACK
) Entering passive mode
сообщение. Что означает, мне, по крайней мере, что ISP освобождает/отбрасывает тот пакет.
Я должен связаться с ISP с той информацией?
Провайдер только что связался со мной. Это было сбоем в конфигурации внутри их сети, что привело к сбросу пакета PASV.
.Скорее всего, это связано с проблемой с брандмауэром. В вашей конфигурации proftpd ограничьте порты, которые он будет использовать
PassivePorts 61000 61199
Это ограничит пассивные порты до 61000-61199. Теперь убедитесь, что эти порты открыты в вашем брандмауэре.
Об этом отлично написано здесь