Community Archive (Customer) asked a question.
Error 842c0000
Unfortunately I posted this message in a wrong place, so I copied it here now.
I try to connect to the SFTP site. After completed user authenticated I receive "Error 842c0000 receiving sftp packet" and "Error 842c0000 initializing sftp packet" errors.
In the log it says also that "Server sent larger sftp packet than requested. 1416128883 instead of 30000 bytes.
When I use another client I connect with no problem. I google the problem and found this: "WS_FTP is violating SSH protocol by sending more data that SSH server is prepared to accept at the time (over the so called window size). It's a serious offense (in SSH protocol) that Ipswitch was reluctant to fix,..."
Can anybody help?
Thank you
Check the RFC carefully. https://tools.ietf.org/html/rfc4253
6.1. Maximum Packet Length
All implementations MUST be able to process packets with an
uncompressed payload length of 32768 bytes or less and a total packet
size of 35000 bytes or less (including 'packet_length',
'padding_length', 'payload', 'random padding', and 'mac'). The
maximum of 35000 bytes is an arbitrarily chosen value that is larger
than the uncompressed length noted above. Implementations SHOULD
support longer packets, where they might be needed. For example, if
an implementation wants to send a very large number of certificates,
the larger packets MAY be sent if the identification string indicates
that the other party is able to process them. However,
implementations SHOULD check that the packet length is reasonable in
order for the implementation to avoid denial of service and/or buffer
overflow attacks.
I have read other FTP over SSH servers having similar issues.
Steps I would take
A) Find out what FTP Server the partner you are uploading to is using.
B) Search for that server's notes about compatibility with WS_FTP Pro
C) Check your windows TCP IP Stack settings. I believe you can set the sliding window and MTU sizes and see if this helps. I believe WS_FTP will use the Windows TCP/IP Stack settings and this should help out sending the right size of packets.
Andrei
<b>Thank you very much for your help. Unfortunately, IPSWITCH WS_FTP PRO trial finished, but if we buy the license I will try to do what you suggested.</b>
<b>Again, thank you for your help.</b>