Incorrect directory listing on "Failed to connect to host" exception

[pdavis86]

FTP OS: Windows

FTP Server: Azure Web App

Computer OS: Windows

FluentFTP Version: 34.0.0

When running a lot of operations I have found that sometimes the connection drops so a new IOException("Failed to connect to host.") is thrown on line 919 of FtpSocketStream.cs. That exception is then caught and ignored by line 608 of FtpClient_Listing.cs with the comment "// suppress all other types of exceptions". The result is that there is a silent failure and FluentFTP incorrectly returns that the directory contains no files.

[jsantos74]

I have the same problem in version 34.0.1.

I think I found the problem in my case. Azure Web App have multiple IP's for the same host and the list always failed when the IP changed suddenly from one to another:

Example:

• List Folder 1 on SERVER_1:
  • GetHostAddresses for SERVER_1 returns IP_1 , IP_2, IP_3
  • Connect to IP_1:21 of SERVER_1
  • Enter Entering Extended Passive PORT_1
  • GetHostAddresses for SERVER_1 returns IP_1 , IP_2, IP_3
  • Connect to IP_1:PORT_1
  • OK. List
• List Folder 2 on SERVER_1:
  • GetHostAddresses for SERVER_1 returns IP_1 , IP_2, IP_3
  • Connect to IP_1:21 of SERVER_1
  • Enter Entering Extended Passive PORT_2
  • GetHostAddresses for SERVER_1 returns IP_2, IP_3 , IP_1
  • Connect to IP_2:PORT_2
  • Not OK - Connection Failed...

I've Changed the code and tested and it's startted to work fine.

[pdavis86]

Looks like the change in 34.0.2 had decreased the frequency of the issue but I am still sometimes seeing empty enumerable on calling GetListing() but a second attempt does retrieve the listing

[FanDjango]

I would like to refer this to #1030 - because of "When running a lot of operations". Let me close this and please follow the #1030 issue, please.