SSH / Telnet Software

Telnet is an application layer protocol used on the Internet or local area networks to provide a bidirectional interactive text-oriented communication facility using a virtual terminal connection. SSH was designed as a replacement for Telnet and for unsecured remote shell protocols. The term telnet is also used to refer to the software that implements the client part of the protocol. SSH provides a secure channel over an unsecured network in a client-server architecture, connecting an SSH client application with an SSH server.

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Our Information Security team has identified multiple machines that have OpenSSH installed and I am trying to find a way to uninstall the application from all machines relevant and have been unable to. I know I can disable the services but they want it removed as well.
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I have a security related question on Linux Ubuntu.
Can we remove sudo access to root console for power users.
But still allow admin to ssh to the servers with root password.
As a security measure is it a good idea to disable root access to everyone if  connecting to servers remotely.

If I ssh to connect to a CentOS Linux server - and from that server I want to open
say five SSH sessions and tab or control or however jump back and forth between
those five session - how could one do that?  Is that a standard capability?

How to resolve this error SFTP error #3 Permission denied mobaxterm to access on redhat VM lucky directory. thanks
VBOXerr1.txtSSH connection refused when running SSH (putty) from my WINDOWS PC a  an ORACLE LINUX running on the same PC on Oracle Virtual BOX.

PUTTY displays the error:
PUTTY Network  error:  Connection refused  on

Sure, something is wrong. Could you help?


I already attached a log from the Windows8  machine (ipconfig ).
What I am ryng to do is connect from Windows using putty (SSH) to the VM Linux running on the same machine .
Someone can give any advice?

See below the ifconfig of the VM Linux machine:

root@ServidorLinux7 ~]# ifconfig
enp0s3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet  netmask  broadcast
        inet6 fe80::52d0:9ddb:1f83:48f2  prefixlen 64  scopeid 0x20<link>
        ether 08:00:27:5d:46:25  txqueuelen 1000  (Ethernet)
        RX packets 6787  bytes 4818007 (4.5 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 4517  bytes 617833 (603.3 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet  netmask
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 0  (Local Loopback)
        RX packets 46  bytes 7314 (7.1 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 46  bytes 7314 (7.1 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  …
Dear Experts,

I am thinking to use SSIS to do the following procedure.

(1) copy many files to Linux machines. then
(2) execute a Linux program (command) to analysis those files. The program will output the result to the local Linux drive
(3) when (2) is done, then pull the result back to Windows machine

For (1) I am thinking of FTP task (by FTP or SFTP)

how about the task of (2) and (3) ?  Could you please help ... Thanks
This is using IBM storwiz v3700 storage. The SSH service is available and we can connect with this SSH by using the assigned user account with correct password. BTW, how to change so as instead of using password, create the key-pair for the dedicated user account?

Thanks in advance.
I need to provide a SFTP service to let my data providers upload files securely.

Do you know a good and affordable hoster?

I don't feel comfortable opening my servers to the web!
Hi All,

I setup a Server A as a telnet server. Then client A is using putty to telnet into Server A.
I successfully connect to the server and can run commands but when I try and open an exe. Nothing happens
It just returns  an empty line.When I go to Server A and open command prompt and execute the program it runs inside the command prompt window.
So not sure what I am doing wrong in the telnet setting for the program not to be starting.
Previously when we transferred a 20GB gz  Solaris file down to PC's
local HDD & then from the local PC HDD, transfer to a USB HDD, our
DLP corrupted the gz file when it's transferred from local HDD to USB

We have since resolve that but to prevent untoward corruption in
future for copying of critical files to USB HDD,

Does Winscp has checksum feature that checks at Unix end & at
PC end?

If so I would rather use Winscp to transfer directly to USB HDD.
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BitVise SSH Client
I am new to sFTP.  I installed BitVise SSH Client successfully.  I can connect SSH Server via GUI and download files ok.  But I want to automate and download files without going through GUI.  Any suggestions for command-line script for file download?  I think sftpc is the one to use.  But I don't know to use it.  My setting is Initial method: publickey. Client key: Profile 1.  

sftpc 'SSH Server Name' - I could connect to the remote SSH Server. Then, it prompts for Password.  But there is no password.

Thank you very much in advance.
Hi Experts,
can someone explain the procedure for generating certificates.

I am new to this I want to Generating private key for SFTP connection, i have a file that has a *.asc extension and i want to generate to private key and send it to third party.

Thank you,
After 30+ hours of research and trying different solutions I have found many solutions to each piece of this puzzle but can't quite get them to work together or figure out the best approach so I'm hoping you guys can help.

The goal: Use public IP from a remote server(Ubuntu) as a browser proxy. The kicker is that the server should pass all traffic through to a local machine which has a 4g modem internet connection to use its internet connection. We need to be able to assign fixed IP addresses/IP port combinations to these local modem/s to be used as undetectable browser proxies to make it appear that the browser client is logged in using the mobile internet connection.

I have seen multiple solutions to each part of this including the use of ssh tunnels, dynamic port forwarding/socks, remote port forwarding, squid proxy server/other proxy server software, iptables configs etc..

I have found this solution that I can get traffic to travel from anywhere to my local machine:

//1st terminal establishes connection/tunnel ssh -nN -R 8888:localhost:8889 -i "connection.pem"

//2nd terminal listens on port 8889 netcat -l -p 8889 //this command works and prints abc on the local machine echo "abc" | nc -v xx.xx.xx.xx(remote server ip) 8888

I have also successfully installed a squid proxy server in a docker container and used the following command to open socks connection with reverse forwarded port.

//Socks/Dynamic forwarding with…
I have several linux systems. Normally I login on them with my account, and after I login i execute sudo -s, so I can get admin privileges.
Sometimes I need to edit some files or copy some files out of the linux systems and in the past I ofter used the winscp program.
Unfortunately when I login with winscp with my account I don't have admin privileges, and thus I am not able to open and edit needed files, I am not able to copy files out of the system. Can you tell me how to login with winscp with admin privileges
Hello Experts,
Seemingly out of the blue (starting July 29th), though possibly corresponding with installing VMware Tools on the server (7/22), or, less likely I think, updating our ERP software including telnet server (7/21) and OS updates (7/21 - see attached), our Server 2012 R2 VM has been acting up.

I have been rebooting a telnet server service daily for two years+ to kick out clients that didn't log out and had their then sessions hang, which frees up licenses for new clients to log on in the morning. Recently, this has caused the server to not accept new connections on port 23. Nothing seems to fix it except for an OS reboot. The corresponding message in the Event Viewer is from AFD:

Closing a TCP socket with local port number 23 in process 16584 is taking longer than expected. The local port number may not be available until the close operation is completed. This happens typically due to misbehaving network drivers. Ensure latest updates are installed for Windows and any third-party networking software including NIC drivers, firewalls, or other security products.

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This happens reliably now every time the telnet service is restarted. The process ID corresponds to the telnet server. Killing the process (that was restarted initially and caused this error) does not then allow connections on 23 - the OS must be rebooted. Disabling and then enabling the network adapter does not help. I reinstalled VMware tools which did not help.

Another error from Tcpip may be related started happening about a week later (8/7) and has been occurring daily or up to six times a day since:

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Hello All,

We receive an instruction to upgrade to Dropbear SSH version, but I have no idea about this. Can you please me understand this please?

I want to automate the file transfer.
FTP Client : Reflection FTP Client
SFTP Server : Tectia SFTP Server.
I tried using similar to winscp scripts powershell but it didnt work.
Can someone help me providing the script which will work to transfer file to sftp server running script.
Authentication method is public key + password authentication and password must be encrypted.
My company has setup an Ubuntu 18.04 server, to exchange files with a client, via SFTP.  We need a high level of security.  We're trying to require authentication with SSH key pairs, AND the Linux OS username and password (not the SSH passphrase). We've got the key pairs working, but it doesn't ask for the password. I'm assuming we're just missing something in the sshd_config file. Hopefully we're not trying to do something that's not possible. Any assistance would be much appreciated.

I had this question after viewing How to connect to multiple parallel SFTP using JSCH?.

Is it possible to have multiple SFTP connections for the same host,username and port??
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Hi, when I finished installing OpenSSH, I got the following warning:

Permissions 0640 for '/etc/ssh/ssh_host_ecdsa_key' are too open.

Could you please give me the command line to safely change and set the proper permissions for this folder and its files?

Server: Red Hat Enterprise Linux Server 7.5


Jorge Batres
I am running a Centos 7 linux server, i am runnin open ssh server, and client. I did a recent test to see if the ssh is working correctly, and what i found out was i could only using my internal IP address to access my server from my workstation. I tried to use the public static ip and i get a timed out error. I checked my ports 21,22,  to make sure they are open through port forwarding through my wireless router. They check out to be open, I am using firewalld as a firewall, and i  did notice that my selinux gave me an message basically asking me do i want the sshd server access to a particular file. I am not sure if selinux is the issue. But i want to find out if it is a permission problem, or  selinux issue. The actual sshd server when checked on staus shows it is running fine. Please help
We have a Linux server and after it was scanned for any security vulnerabilities, we got one about "SSH Weak Algorithms Supported".  I tried to make a change to the ssh_config file under /etc/ssh/ to remove the support for any "arcfour" algorithm, but after another scan, it is still showing that this vulnerability exists.  Can anyone tell me exactly what I need to change?  This is my line in the ssh_config file:

 Ciphers aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc

Thanks in advance!
- Christian
I removed the public SSH key from a server I was managing. THen I generated a new key and overwrote the old one on my laptop. THen I added the key to the server. it added two keys.

I thought it would be best practice to remove the old key and put the new one in. It seems like my old key is still being added to the server. Am I overthinking this?

Does it really not matter and should you not bother with changing SSH keys? I was going to change them by the business quarter.
Hi guys

I'm trying to set up an SFTP server for our company to use. I have a Windows 2012 server and have started to go down the open ssh route etc.

Do you guys have any guides one could follow or recommendations you would make?

If people think Linux would be a better route, then I can go down that route too. I need something that will be stable and not lose/drop connectivity because of some sort of service that needs restarting all of the time etc.

And I have to do this within the next 3hrs:).

Thanks for helping
Would someone have an explanation for this?

Both times I have run this script.

vmkfstools -i "/vmfs/volumes/Date-2016/00 - DNS Server/00 - DNS Server.vmdk" -d thin "/vmfs/volumes/DES Lessons/00-DNS-Serve
r/00 - DNS Server.vmdk"

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It gets to around 45%, and then jumps to 100%

Destination disk format: VMFS thin-provisioned
Cloning disk '/vmfs/volumes/Date-2016/00 - DNS Server/00 - DNS Server.vmdk'...
Clone: 100% done.

However, the actual size is 50GB
But the file transferred is only 16GB

00 - DNS Server.vmdk
16.53 GB
Sunday, May 20, 2018, 12:48:59 -0400

This is the actual size

00 - DNS Server.vmdk
50 GB
Saturday, April 28, 2018, 08:23:53 -0400

I have 7 VMs that need to be moved to a new drive, and this is causing some major slowing down issues.
Any ideas?

Also, if using the vmkfstools GUI is a better route to go, that would complete this without this issue.
Then please, tell me how to use the GUI, as I cannot find any information on using it.


SSH / Telnet Software

Telnet is an application layer protocol used on the Internet or local area networks to provide a bidirectional interactive text-oriented communication facility using a virtual terminal connection. SSH was designed as a replacement for Telnet and for unsecured remote shell protocols. The term telnet is also used to refer to the software that implements the client part of the protocol. SSH provides a secure channel over an unsecured network in a client-server architecture, connecting an SSH client application with an SSH server.

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SSH / Telnet Software