my original question: FTP client/server failing on switching to PASV mode
Based on that, I would like to know if/how I can open a FTP connection from a computer that is inside a ISP's network that uses Dual-Stack Lite to a FTP server that is only reachable via IPv4.
Obviously, passive FTP doesn't work, but would active FTP work (if I added port-forwarding on the owner's router)?
Update The ISP said that they recently added the area where this computer is located to their IPv6 network. Coincidentally, ever since the day they added that area to their IPv6 network, no FTP connection was possible.
The ISP was able to set this specific connection back to IPv4 (for a limited amount of time) and...FTP worked again.
Original descirption of the problem
I've a TCP level problem between FTP clients and FTP servers (I think it's a proftp server but I'm not sure).
Upon requesting PASV mode for data transfer, the client receives an ACK but does not receive the 227 entering passive mode message. The client waits for 30 seconds before it sends a TYPE A request which the server tries to ACK, but with the wrong SEQ number.
The SEQ number contains the size of the Enter passive mode message. The server also sends a 200 Switching to ASCII mode which also has the wrong SEQ number.
From there it's 7 tries of TCP Retransmission and TCP DUP ACK while both sides are using 'their' SEQ numbers. (Shouldn't the unconfirmed message that the server sent be retransmitted? Meaning, shouldn't the server just sent the 227 entering passive mode message again? Or at least fix the SEQ number?)
I got multiple questions here. For one, which side is behaving wrong here? One side has to fix it's SEQ number, but who? And how can a specific message (it's always the Entering passive mode message) always get lost?
To make matters more strange this is happening only on one computer. Out of hundreds. And it's also only happening with one FTP server. (which I don't have control over). The server and the computer in question are connected via the internet.
The logs were acquired via the client's router, so it's not a PC problem.
Ok, I managed to filter the protocol. So here it is:
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
edit
I checked with another FTP server that is under my control and stuff get's weird now (read: it's not working with that one either). According to my server, it is communicating with an IPv4 address ending on .0. For the record, I'm located in Germany. I've never seen an IPv4 address ending on .0 before.
If I check the router on the client side it reports a completely different public IPv4 address (at least that one looks valid) and it also reports a IPv6 address (extremely seldom in Germany to have one. Depends on the ISP.)
And my server's logs are saying that it is sending (and also retransmitting, as it's not getting an ACK) the Entering passive mode message. Which means, to me at least, that the ISP is loosing/dropping that package.
Should I contact the ISP with that information?
I've kind of a weird problem on one of our customer's backup harddrives: The harddrive is formatted in FAT32 and last night our backup jobs threw an error on a subdirectory, claiming that it couldn't copy the files that it had to copy.
I checked the disk size first of course, but there is plenty of space. The error given was 0x80070052, if I put that into a search engine I get results like this: http://www.quickonlinetips.com/archives/2007/09/how-to-fix-error-0x80070052-on-usb-flash-drives/
But there are just 8 files/directories in the root directory of that partition. So I went on and decided to test some stuff myself. Creating a single file (named 'test.txt' for example) did work. But creating a file with one of the filenames that the backupjob failed on, didn't work, instead I got the same error as above. I tested around a little bit and found out that I can create a file with 10 characters in that sub-directory, one character more and it fails.
After detecting that, I created a directory in that subdirectory (named 'test') and moved some files from the sub-directory into the new directory, after that finished, I tried to create a file with 11 characters (which didn't work before) and it worked.
Now, obviously from observation, there seems to be some kind of hardlimit on how many characters can be used for all filenames inside a single directory for FAT32, but I couldn't find anything about that hard limit or if other file systems (especially NTFS, which would be the alternative in this case, I guess) have similiar limits.
If someone could provide me with informations about the observed behaviour, that'd be great!
edit
a colleague told me to put the exact folder on another FAT32 drive, since he once had problems with the USB controller of a particular manufacturer. I tried two USB sticks from different manufacturers, both FAT32 formatted, both showed the exact same behaviour as described above.
To get you an idea of the amount of files involved: There are roughly 10200 files, each with a filename between 80 and 110 characters in length, excluding the filepath (that doesn't seem to be of any matter), so there are circa one million characters involved.
I've installed qemu and AQEMU on my Ubuntu 13.04 from default repository. I created a virtual machine by using the wizard and set the harddisk to 10 GiB.
I added a Debian 7.1 .iso file to the device manager and fired the machine up. As expected, the iso file was recognized and I was able to start the installation process.
The entire installation went without any errors or warnings. The partitioning, everything was great.
Even when I restarted the VM, after the installation finished, I was able to boot into the new system. After some toying around with it, I shut it down to remove the iso image, when I tried to start again, the 'BIOS' said that there was no partition to boot from. I looked around, and found that the .img file that should hold the virtual disk was only 197,1 kB.
Thinking I made some error I did the entire process again...and again...and again. I tried to create snapshots (which worked, at least I didn't got any error) but when I tried to start from those after shutting the VM down, I just got a black screen, nothing else. Also the img file never changed in size.
I tried to click 'Save', which just brought up a prompt that I can't save in snapshot mode (wtf?).
I'm kind of clueless now. Also I'm frustrated. Where is the installation process going? Why are there no error messages? What am I doing wrong? Is there some hidden command I've to use? I can't even find anything via a search engine that even remotely connects to my problem. And I don't get any errors on stdout, either.
The .img file is in my home directory, so I've read/write permissions.
I'm using Apache 2.2 instead of 2.4, which explains the error in the title. After Brain99 posted his comment, I found out that I had 2.2, adjusted my configuration to what he suggested (which still didn't work), tried around a bit, slept a night and the next day I found out, that I forgot the Include statements for the mod-enabled directory!
For now I just need the server to let me download files from one specific folder (in my case I chose /opt/myFolder for that task)
Distribution is Debian 6.0
edit_start
Apache version is 2.4, according to their official documentation, the Order/Allow clauses are deprecated and should not be used anymore
I'm an idiot: Apache version is 2.2.
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My directory directives in apache2.conf look like this:
<IfModule dir_module>
DirectoryIndex index.html index.htm index.php
</IfModule>
ServerRoot "/etc/apache2"
DocumentRoot "/opt/myFolder"
<Directory />
Options FollowSymLinks
AuthType None
AllowOverride None
Require all denie
</Directory>
<Directory "/opt/myFolder/*">
Options FollowSymLinks MultiViews
AllowOverride None
AuthType None
Require all allow
</Directory>
When I try to access a file inside that folder (http://myserver.de/aTestFile.zip) I get an Internal Server Error. Also Apache writes the following error into it's log:
configuration error: couldn't check user. Check your authn provider!: /aTestFile.zip
Why would I need an authn provider if I don't want any authentication? Also I hope someone can explain to me what kind of AuthenticationProvider I'd need for that. Everytime I search for those things I get pointed at people asking how to protect files/directories with passwords or restrict access to some IP addresses, which doesn't really help me.
ok, since I've Apache version 2.2, here is the error I get when using the Order/Deny/Allow commands instead of AuthType/Require:
Invalid command 'Order', perhaps misspelled or defined by a module not included in the server configuration.
I'm trying to install a Debian 6 (newest version) on a Server which has 2 RAIDs.
First RAID is configured on an Intel controller and is a simple RAID 1 with 3 partitions (swap, /, and a special data partition)
Second RAID (not important here) is on another RAID controller, 1 TB. Everything fine with that one.
So, my problem: When I enter the Debian installation routine and get to parted, it won't let me change anything regarding the Intel RAID (aside from deleting it...which works over the Software RAID menu...strange, right?). The RAID controller is listed as something like "raidmd126 RAIDACTIVE #(readonly) $harddrive1 $harddrive2". There is one partition listed, which goes over the whole space, I can try to mount it and make it ext4 but when I want to go to the next step and parted tries to commit those changes I get an error, saying that this operation is not allowed.
If I change to a shell (ash) and enter dmesg I can see that Debian says something about an unknown partition table. I entered the Intel RAID controller menu several times and created the RAID new, but it didn't change anything.
Previously on that machine was a Suse 11 installed, it worked fine with the RAID controller.
So, question is: Why did it work with Suse but won't work with Debian? / How to make it work with Debian?