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Questions tagged [telnet]

For questions about Telnet, a protocol for bidirectional interactive text-oriented communication with remote hosts via virtual terminals. It is defined in RFC 854.

Telnet is a protocol for bidirectional interactive text-oriented communication with remote hosts via virtual terminals. It is defined in RFC 854.

Telnet provides no inherent security and so is becoming less commonly supported. On modern UNIX-like systems it is usually replaced with more secure and flexible SSH protocol.

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smart client for dumb tcp socket?

I have a server that listens to simple tcp sockets. If connecting to it, it prints a prompt and I can type commands, hit enter, see (and save) results, and then have the prompt again. I'm using telnet right now to connect, but want something more…
IttayD
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OS X Server: SMTP Server problem

I have problem to setup my mail server. My system is a OS X 10.6.2. Server. I configured the mail server so far, but I cannot connect to the smtp server correctly. Correctly means that I can connect via telnet (and do the "HELO") from another server…
plucked
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Linux: telnet arrives to target but no response

We have server in AWS that's trying to connect over TCP to an application in an on premise server but fails. Initially we thought it might be routing/firewall issues so we tried to connect to that application using telnet on the specific port it's…
Tomer Arazy
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Postfix + Dovecot and folder "sent mail"

We’re using for sending mails our own mail server Postfix + Dovecot with parameter for Postfix sender_bcc_maps which ensures that sent mail thanks to blind copy (BCC) is also sent to a sender’s address „sender+sent@email.domain“. That way is mail…
Nichlaus
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Windows to Linux Ping not working while Telnet works

On Linux we have a service running which is listening on port 9999 but when we try to check it from a Windows machine on same network with PING it says : Ping request could not find host 10.32.9.82:9999 while when I tried using telnet like telnet…
Ehsan Sajjad
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Postfix - How to enable SMTP authentication on local delivery

I have an email server running Postfix. Everything is working fine, However, recently, some internal emails received emails from their own addresses with phishing content. After finding out, I learned that Postfix can send internal emails using…
Vu Hoang Long
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How to connect to mail.hotmail.com via port 25 from DNS as instructed by Outlook

If you read https://sendersupport.olc.protection.outlook.com/pm/troubleshooting.aspx, it says Confirm that your DNS is set up correctly Try connecting to mail.hotmail.com via port 25. If you are unable to connect, then attempt to telnet over port…
cilapo1541
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Service sometimes working, sometimes not working

I want to connect Centos B's 33060 port from Centos A. I can ping Server B. [root@serverb ~]# ping 10.42.40.182 PING 10.42.40.182 (10.42.40.182) 56(84) bytes of data. 64 bytes from 10.42.40.182: icmp_seq=1 ttl=56 time=1.51 ms 64 bytes from…
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Execute command on LINUX via PUTTY from Windows

I want to open a putty session (SSH) from command line and immediately execute on the remote machine a specific command. Something like: putty.exe -ssh user@host -pw pass123 < "cd /some/directory; ll" But this doesn't work. Is it possible?
Mr.Eddart
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Test TLS TCP Endpoint

I have TCP endpoint for a Service running with TLS (Self-Signed) Certificate. To test this endpoint I use openssl s_client -connect service.domain.com:5050 which prints CONNECTED(00000006) nothing else. I have cert & key for the self-signed…
roy
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VMWare network: some guest service not accessible from host

I have elastic search installed on a guest (CentOS7) on my vmware host, I am able to visit it on the default port 9100: If I access it from the guest directly, it shows differently: If I telnet from host to guest on port 9200, I got this: So it…
mdivk
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Telnet shows blank screen on port 443 but TCP handshake not done

From my windows 10 machine (172.18.164.50) if I do a telnet 172.20.187.10 443 It shows a blank screen as if it is connected. It is totally unespected because in theory a firewall is blocking the traffic to port 443. Looking in Message Analyser…
user506420
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How can I abort a telnet connection attempt?

Suppose I execute the following in command prompt: telnet XXX.XXX.XXX.XXX 80 half a second later, I realize it would never connect (for whatever reason). I want to abort the connection attempt instead of waiting for it to timeout. Pressing either…
kevin
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EXIM SMTP allows to send mails without login / authentication via telnet to any domain

I'm ashamed, but I have to ask for help. My server is being used for sending spam, I've found out I can simply connect with telnet (edit: from any server in office, home and even directly from CMD/Putty Telnet), add mail from/rcpt to/data without…
Mateusz
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How can I enable SMTP receipt through firewalld on Linux?

I've leased a dedicated, lightly-managed CentOS7 box from a hosting company. The host came with firewalld installed and running and with its iptables preferences pre-imposed. I was not expecting this; I'm used to receiving unfirewalled boxes with…
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