5

I'm trying to set up an SSH tunnel in PuTTY to connect to a RHEL server's database using MySQL Workbench over SSH.

  • I set up an SSH session on port 22 to the server, then under SSH > Tunnels, I forward local port 49900 to the remote server's 3306 (L49900 remoteserverip:3306).

    In Workbench, I try to connect to localhost on port 49900 after establishing the SSH connection through PuTTY, but it fails to connect: Unable to connect to 127.0.0.1:49900

I have an identical setup on my laptop (W10 Enterprise v1809) and it works fine, with both the PuTTY and Workbench configs exported from my laptop. When trying the same thing on my desktop (W10 Pro v1909), Workbench errors with Unable to connect to 127.0.0.1:49900

I've tried testing the port in Powershell on Windows 10 (below), as well as on two other servers (none of them works, including forwarding web ports):

  • Desktop:
    Test-NetConnection -ComputerName 127.0.0.1 -Port 49900
    WARNING: TCP connect to (127.0.0.1 : 49900) failed
    ComputerName           : 127.0.0.1
    RemoteAddress          : 127.0.0.1
    RemotePort             : 49900
    InterfaceAlias         : Loopback Pseudo-Interface 1
    SourceAddress          : 127.0.0.1
    PingSucceeded          : True
    PingReplyDetails (RTT) : 0 ms
    TcpTestSucceeded       : False
    
  • Laptop:
    Test-NetConnection -ComputerName 127.0.0.1 -Port 49900
    ComputerName           : 127.0.0.1
    RemoteAddress          : 127.0.0.1
    RemotePort             : 49900
    InterfaceAlias         : Loopback Pseudo-Interface 1
    SourceAddress          : 127.0.0.1
    PingSucceeded          : True
    

My keys are correct, as I use the same .ppk on both my machines and I can connect to all my servers from both machines - only the forwarding does not work on the desktop machine.

  • PuTTY Log:
    • Desktop:
      Incoming packet 0x6, type 52 / 0x34 (SSH2_MSG_USERAUTH_SUCCESS)
      Event Log: Access granted 
      Event Log: Local port 49900 forwarding to [remoteip]:3306 failed: Network error: Permission denied
      
    • Laptop
      Incoming packet 0x7, type 52 / 0x34 (SSH2_MSG_USERAUTH_SUCCESS)
      Event Log: Access granted
      Event Log: Local port 49900 forwarding to [remoteip]:3306 
      Event Log: Opening main session channel Outgoing packet 0x8, type 90 / 0x5a (SSH2_MSG_CHANNEL_OPEN)
      
  • PuTTY Profile:
    [HKEY_CURRENT_USER\Software\SimonTatham\PuTTY\Sessions\BF%20login]
    "Present"=dword:00000001
    "HostName"="*****************"
    "LogFileName"="C:\\putty.log"
    "LogType"=dword:00000004
    "LogFileClash"=dword:ffffffff
    "LogFlush"=dword:00000001
    "LogHeader"=dword:00000001
    "SSHLogOmitPasswords"=dword:00000001
    "SSHLogOmitData"=dword:00000000
    "Protocol"="ssh"
    "PortNumber"=dword:00000016
    "CloseOnExit"=dword:00000001
    "WarnOnClose"=dword:00000001
    "PingInterval"=dword:00000000
    "PingIntervalSecs"=dword:00000000
    "TCPNoDelay"=dword:00000001
    "TCPKeepalives"=dword:00000000
    "TerminalType"="xterm"
    "TerminalSpeed"="38400,38400"
    "TerminalModes"="CS7=A,CS8=A,DISCARD=A,DSUSP=A,ECHO=A,ECHOCTL=A,ECHOE=A,ECHOK=A,ECHOKE=A,ECHONL=A,EOF=A,EOL=A,EOL2=A,ERASE=A,FLUSH=A,ICANON=A,ICRNL=A,IEXTEN=A,IGNCR=A,IGNPAR=A,IMAXBEL=A,INLCR=A,INPCK=A,INTR=A,ISIG=A,ISTRIP=A,IUCLC=A,IUTF8=A,IXANY=A,IXOFF=A,IXON=A,KILL=A,LNEXT=A,NOFLSH=A,OCRNL=A,OLCUC=A,ONLCR=A,ONLRET=A,ONOCR=A,OPOST=A,PARENB=A,PARMRK=A,PARODD=A,PENDIN=A,QUIT=A,REPRINT=A,START=A,STATUS=A,STOP=A,SUSP=A,SWTCH=A,TOSTOP=A,WERASE=A,XCASE=A"
    "AddressFamily"=dword:00000000
    "ProxyExcludeList"=""
    "ProxyDNS"=dword:00000001
    "ProxyLocalhost"=dword:00000000
    "ProxyMethod"=dword:00000000
    "ProxyHost"="proxy"
    "ProxyPort"=dword:00000050
    "ProxyUsername"=""
    "ProxyPassword"=""
    "ProxyTelnetCommand"="connect %host %port\\n"
    "ProxyLogToTerm"=dword:00000001
    "Environment"=""
    "UserName"=""
    "UserNameFromEnvironment"=dword:00000000
    "LocalUserName"=""
    "NoPTY"=dword:00000000
    "Compression"=dword:00000000
    "TryAgent"=dword:00000001
    "AgentFwd"=dword:00000000
    "GssapiFwd"=dword:00000000
    "ChangeUsername"=dword:00000000
    "Cipher"="aes,chacha20,3des,WARN,des,blowfish,arcfour"
    "KEX"="ecdh,dh-gex-sha1,dh-group14-sha1,rsa,WARN,dh-group1-sha1"
    "HostKey"="ed25519,ecdsa,rsa,dsa,WARN"
    "RekeyTime"=dword:0000003c
    "GssapiRekey"=dword:00000002
    "RekeyBytes"="1G"
    "SshNoAuth"=dword:00000000
    "SshBanner"=dword:00000001
    "AuthTIS"=dword:00000000
    "AuthKI"=dword:00000001
    "AuthGSSAPI"=dword:00000001
    "AuthGSSAPIKEX"=dword:00000001
    "GSSLibs"="gssapi32,sspi,custom"
    "GSSCustom"=""
    "SshNoShell"=dword:00000000
    "SshProt"=dword:00000003
    "LogHost"=""
    "SSH2DES"=dword:00000000
    "PublicKeyFile"=""
    "RemoteCommand"=""
    "RFCEnviron"=dword:00000000
    "PassiveTelnet"=dword:00000000
    "BackspaceIsDelete"=dword:00000001
    "RXVTHomeEnd"=dword:00000000
    "LinuxFunctionKeys"=dword:00000000
    "NoApplicationKeys"=dword:00000000
    "NoApplicationCursors"=dword:00000000
    "NoMouseReporting"=dword:00000000
    "NoRemoteResize"=dword:00000000
    "NoAltScreen"=dword:00000000
    "NoRemoteWinTitle"=dword:00000000
    "NoRemoteClearScroll"=dword:00000000
    "RemoteQTitleAction"=dword:00000001
    "NoDBackspace"=dword:00000000
    "NoRemoteCharset"=dword:00000000
    "ApplicationCursorKeys"=dword:00000000
    "ApplicationKeypad"=dword:00000000
    "NetHackKeypad"=dword:00000000
    "AltF4"=dword:00000001
    "AltSpace"=dword:00000000
    "AltOnly"=dword:00000000
    "ComposeKey"=dword:00000000
    "CtrlAltKeys"=dword:00000001
    "TelnetKey"=dword:00000000
    "TelnetRet"=dword:00000001
    "LocalEcho"=dword:00000002
    "LocalEdit"=dword:00000002
    "Answerback"="PuTTY"
    "AlwaysOnTop"=dword:00000000
    "FullScreenOnAltEnter"=dword:00000000
    "HideMousePtr"=dword:00000000
    "SunkenEdge"=dword:00000000
    "WindowBorder"=dword:00000001
    "CurType"=dword:00000000
    "BlinkCur"=dword:00000000
    "Beep"=dword:00000001
    "BeepInd"=dword:00000000
    "BellWaveFile"=""
    "BellOverload"=dword:00000001
    "BellOverloadN"=dword:00000005
    "BellOverloadT"=dword:000007d0
    "BellOverloadS"=dword:00001388
    "ScrollbackLines"=dword:000007d0
    "DECOriginMode"=dword:00000000
    "AutoWrapMode"=dword:00000001
    "LFImpliesCR"=dword:00000000
    "CRImpliesLF"=dword:00000000
    "DisableArabicShaping"=dword:00000000
    "DisableBidi"=dword:00000000
    "WinNameAlways"=dword:00000001
    "WinTitle"=""
    "TermWidth"=dword:00000050
    "TermHeight"=dword:00000018
    "Font"="Courier New"
    "FontIsBold"=dword:00000000
    "FontCharSet"=dword:00000000
    "FontHeight"=dword:0000000a
    "FontQuality"=dword:00000000
    "FontVTMode"=dword:00000004
    "UseSystemColours"=dword:00000000
    "TryPalette"=dword:00000000
    "ANSIColour"=dword:00000001
    "Xterm256Colour"=dword:00000001
    "TrueColour"=dword:00000001
    "BoldAsColour"=dword:00000001
    "Colour0"="187,187,187"
    "Colour1"="255,255,255"
    "Colour2"="0,0,0"
    "Colour3"="85,85,85"
    "Colour4"="0,0,0"
    "Colour5"="0,255,0"
    "Colour6"="0,0,0"
    "Colour7"="85,85,85"
    "Colour8"="187,0,0"
    "Colour9"="255,85,85"
    "Colour10"="0,187,0"
    "Colour11"="85,255,85"
    "Colour12"="187,187,0"
    "Colour13"="255,255,85"
    "Colour14"="0,0,187"
    "Colour15"="85,85,255"
    "Colour16"="187,0,187"
    "Colour17"="255,85,255"
    "Colour18"="0,187,187"
    "Colour19"="85,255,255"
    "Colour20"="187,187,187"
    "Colour21"="255,255,255"
    "RawCNP"=dword:00000000
    "UTF8linedraw"=dword:00000000
    "PasteRTF"=dword:00000000
    "MouseIsXterm"=dword:00000000
    "RectSelect"=dword:00000000
    "PasteControls"=dword:00000000
    "MouseOverride"=dword:00000001
    "Wordness0"="0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0"
    "Wordness32"="0,1,2,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,1,1,1,1,1,1"
    "Wordness64"="1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,1,1,1,1,2"
    "Wordness96"="1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,1,1,1,1,1"
    "Wordness128"="1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1"
    "Wordness160"="1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1"
    "Wordness192"="2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2"
    "Wordness224"="2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2"
    "MouseAutocopy"=dword:00000001
    "MousePaste"="explicit"
    "CtrlShiftIns"="explicit"
    "CtrlShiftCV"="none"
    "LineCodePage"=""
    "CJKAmbigWide"=dword:00000000
    "UTF8Override"=dword:00000001
    "Printer"=""
    "CapsLockCyr"=dword:00000000
    "ScrollBar"=dword:00000001
    "ScrollBarFullScreen"=dword:00000000
    "ScrollOnKey"=dword:00000000
    "ScrollOnDisp"=dword:00000001
    "EraseToScrollback"=dword:00000001
    "LockSize"=dword:00000000
    "BCE"=dword:00000001
    "BlinkText"=dword:00000000
    "X11Forward"=dword:00000000
    "X11Display"=""
    "X11AuthType"=dword:00000001
    "X11AuthFile"=""
    "LocalPortAcceptAll"=dword:00000000
    "RemotePortAcceptAll"=dword:00000000
    "PortForwardings"="L49900=*********************:3306"
    "BugIgnore1"=dword:00000000
    "BugPlainPW1"=dword:00000000
    "BugRSA1"=dword:00000000
    "BugIgnore2"=dword:00000000
    "BugHMAC2"=dword:00000000
    "BugDeriveKey2"=dword:00000000
    "BugRSAPad2"=dword:00000000
    "BugPKSessID2"=dword:00000000
    "BugRekey2"=dword:00000000
    "BugMaxPkt2"=dword:00000000
    "BugOldGex2"=dword:00000000
    "BugWinadj"=dword:00000000
    "BugChanReq"=dword:00000000
    "StampUtmp"=dword:00000001
    "LoginShell"=dword:00000001
    "ScrollbarOnLeft"=dword:00000000
    "BoldFont"=""
    "BoldFontIsBold"=dword:00000000
    "BoldFontCharSet"=dword:00000000
    "BoldFontHeight"=dword:00000000
    "WideFont"=""
    "WideFontIsBold"=dword:00000000
    "WideFontCharSet"=dword:00000000
    "WideFontHeight"=dword:00000000
    "WideBoldFont"=""
    "WideBoldFontIsBold"=dword:00000000
    "WideBoldFontCharSet"=dword:00000000
    "WideBoldFontHeight"=dword:00000000
    "ShadowBold"=dword:00000000
    "ShadowBoldOffset"=dword:00000001
    "SerialLine"="COM1"
    "SerialSpeed"=dword:00002580
    "SerialDataBits"=dword:00000008
    "SerialStopHalfbits"=dword:00000002
    "SerialParity"=dword:00000000
    "SerialFlowControl"=dword:00000001
    "WindowClass"=""
    "ConnectionSharing"=dword:00000000
    "ConnectionSharingUpstream"=dword:00000001
    "ConnectionSharingDownstream"=dword:00000001
    "SSHManualHostKeys"=""
    
1
  • 2
    Comments are not for extended discussion; this conversation has been moved to chat.
    – DavidPostill
    May 18 '20 at 13:56
9

TCP port 49900 is within the port range (49152 to 65535) that is reserved for dynamic ports.

You should not open services using ports in that range. The recommended port range is from 1024 to 49151.

2

Problem solved by changing local port to a lower port (3307). Not sure why it doesn't work with port 49900 on the desktop when it does on the laptop.

1
  • 1
    It's due to that local port on the desktop PC being in use at the moment you're attempting the connection.
    – JW0914
    May 18 '20 at 15:37

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