Hot answers tagged telnet
18
The Telnet client in Windows 7 is disabled by default, and needs to be enabled via Windows' Programs and Features:
Control Panel --> Programs --> Turn Windows features on or off, in the dialog that pops up check-mark "Telnet Client".
For more info see: Why isn't Telnet enabled by default in Windows 7?
And at MS's site you can check out Telnet: ...
14
One way is to limit the number of processes , a user can run.
Just login as root , and edit this file , to add users and configure , their limit.
# vi /etc/security/limits.conf
Add this line to the file
john hard nproc 10
Now user john can create only 10 processes.
14
TELNET communicates with the peer (telnet server) in clear text.
This is a security hazard compared to say the SSH connect.
To this end, the telnet client on windows is disabled by default.
This often comes as a surprise and many sites describe the steps to get it working,
you seem to have found them already :)
For normal purposes, it would be a better ...
13
First, there is no Telnet/Netcat client – they are two separate programs. Second, there is no "the" – there exist at least 10 different Telnet clients and at least 6 different Netcat versions.
OpenSSL has a SSL client tool:
openssl s_client -connect imap.gmail.com:993
This is available for all operating systems. STARTTLS is supported via ...
11
To stop a running fork bomb you might be able to use killall <name> to kill all processes of the bomb. However, since a fork bomb usually results in an incredibly high load on the system you might not be able to SSH into it or execute that. So a reboot might be necessary or at least much faster.
If every user has his own account on the system you can ...
8
Yes, although that would forfeit benefits of compression, and working with chunked GET response or Base64-encoded login/password in SMTP would be painful, so I wouldn't recommend actually using it except for testing purposes, use Perl or python if you want to do something on the web automatically.
Also, if you want to make requests that are ...
8
One word: Netcat
Netcat is the go-to tool for this sort of thing.
You can thrash whatever port you choose with udp packets with something like:
nc -u host.example.com 53 << /dev/random
(53 is your port number)
Or you can send an actual file, or tell it to bind that port and listen as a service, or whatever you like.
7
Telnet can be used for (nearly) raw TCP connections, and you can use character-based protocols with it, but there are some differences:
Therefore, a Telnet client application may also be used to establish an interactive raw TCP session, and it is commonly believed that such session which does not use the IAC (\377 character, or 255 in decimal) is ...
7
If by "manually" you mean "instruct telnet to send SYN and ACK packets", then no. This is done by the operating system, which needs to keep track of all TCP parameters for a connection – sequence numbers, window size, etc.
It would be possible for a program to use raw IP sockets and manage the TCP layer all by itself. But it's generally an incredibly ...
7
Any business that wants to accept incoming email over the internet will need an SMTP server, so that facebook has one isn't unexpected. It is an incoming server, so won't accept facebook source addresses.
It appears to be fairly standard, and wants standard headers:
# telnet 66.220.155.11 25
Trying 66.220.155.11...
Connected to 66.220.155.11.
Escape ...
7
It should have printed something along the lines of
Escape character is '^]'.
If it is ^], try to press Ctrl+] (^X being equivalent to Ctrl+X). You should then enter the telnet console, where you can enter quit to leave telnet.
6
There is no practical way to do this using a telnet client, as you would have to type all of the XML yourself, which is incredibly impractical. There are however several command-line XMPP clients available, as discussed in this stack overflow question.
List of Jabber Console Clients
centericq
Fama IM
GNU Freetalk
mcabber
If you are ...
6
Ctrl-Space sends ASCII NUL. For the general case, System Preferences > Personal > Language and Text > Input Sources, scroll down the list and select Unicode Hex Input. You can then use Shift-Cmd-Space (and, if you disable Spotlight's use of it, Cmd-Space) to switch between input modes or assign it a keyboard shortcut of its own (and presumably another to ...
5
PuTTY can do all of the above, if you are talking about a direct serial connection (plug in cable, etc.)
Install, then open putty and select "Serial". Check the port settings, then Open.
Then, plug in cable and boot up device.
EDIT: To connect two computers together via serial port requires a null modem cable. It's a serial cable that has the inputs and ...
5
To telnet from a Windows computer to a Unix computer you need to ensure that
Windows has telnet client installed (it is not installed in latest Windows)
Windows firewall is not blocking outgoing Telnet (very unlikely)
Windows can resolve server's name (e.g. through DNS or local hosts file)
Unix server has Telnet service enabled (increasingly being disable ...
5
Is it necessary to use telnet?
If not, you can use PsShutdown to shutdown a remote computer. Or, you can use PsExec and call the shutdown command.
psshutdown -u <username> -t 0 -k
psexec -d -u <username> shutdown -t 0 -s
5
You will want to use a network scanning tool. Telnet will play no part in this. Technically you could make a telnet script that would attempt a connection on various ports across an entire subnet. However, that's impractical to say the least.
Look at the OS X version of nmap using the Zenmap GUI. It's all part of the same compiled dmg file that you can ...
5
I'm going to take a risk here and say.. Yes you can. In the same sense that you can telnet to a hostname.
Some people are saying you can't 'cos one says "Telnet is a Layer 3 network protocol. " I don't think that's correct, for one thing, telnet is an application layer protocol, that's layer 7. IP or IPX or whatever else, is the layer 3 network layer ...
4
Outbound communications are generally allowed by default. However, if you were running a Telnet Server, inbound connections would be blocked by default. The exceptions would be if the installer for the Telnet Server opened the ports as a part of the install.
http://technet.microsoft.com/en-us/library/cc732283(WS.10).aspx
4
You need to speak to the people who run the server and ask them if it can be done, and how. Nobody here knows how your server is configured, and there is no such thing as "a standard server".
Odds are, though, that you can't, because nobody sane would allow telnet to a server over the Internet in this day and age. SSH is ubiquitous, effective, and ...
4
Yes, you can use openssl to do this:
$ openssl s_client -crlf -connect mail.domain.com:110 -starttls pop3
This will initiate the session and get the certificate exchange going. You'll see the certificate exchange messages going back and forth, then the standard pop3 prompt:
+OK Hello there.
user username
+OK Password required.
pass passw0rd
+OK logged ...
4
I am pretty sure that there is no actual hard limit as I have done a lot of funky things through telnet.
I can only imagine that as you are hearing a beep, you have reached the limit/buffer of the session and/or the client is simply hard coded to a limit of characters.
If it was a limit on the server, it would of responded with an error upon sending the ...
4
In general, about sending mails, I recommend you to learn more about the protocol you are using: the SMTP protocol.
If you have time, you should read the RFC documents (links can be found at the previous link) which are describing the entire protocol, which commands are available, and how to use them.
4
This is a VERY important thing to be able to do and has saved my bacon on several occasions!
So FOOEY to all those who voted down this question! PLEASE NOTE: I'm referring to the technical question, not the motive. Being able to do this is important for testing ones system, for example. Having the system up and therefore able to use an automated web-based ...
4
The OP stated these commands worked:
sys server load
sys server access http 0
sys server save
sys server disp
The load and save commands should enclose any access command.
Other formats for this command (based on the CLI version)
sys server access [ftp|telnet|web] [access type]
Set the server access type to be 0: ALL, 1: None, 2:LAN only, 3:WAN ...
4
what are the steps … [I] need to do?
Give up on Telnet.
Download Putty,
install it on your Windows 2008 server and
use Putty to connect to UNI1 using the SSH protocol (port 22).
4
Maybe. You may need to use openssl to provide security before the server makes a plain auth method available.
First you need to check what AUTH mechanisms are available. You can do that by passing the AUTH command with no arguments, to the pop server:
$ telnet pop-server.example.com 110
Trying 10.10.10.10...
Connected to pop-server.example.com
Escape ...
3
telnet is not encrypted, your password and all other data will be transmitted as clear text.
"telnet server" means, that windows will listen on port 23 for incoming connections allowing users to login (and allowing non-users try to mess with your computer -> potential risk).
I'm not sure what "telnet client" means in this context, but i guess the windows ...
3
It is completely feasible and is in fact the essence of pre-GUI Unix'es, circa 1970, that this was the only modus operandi available to connect a console terminal to a Unix computer. The legacy of this convention is still with us (and it is not anachronistic though perhaps obscure and subliminal in today's micro-computer systems) and available, especially ...
3
Edit: Of course, it's never that simple. As you've observed, Microsoft's telnet doesn't respond to ^] while waiting for a connection.
If you don't want to wait around, you only have two options:
Kill the telnet process (from another command shell or the task manager), or
Use another telnet client. PuTTY is a good choice, since it will launch as a ...
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