Solved

Stupid Telnet Question

Posted on 2012-03-13
4
441 Views
Last Modified: 2012-06-21
Just a quick one here - I use telnet often to test connectivity to devices through specific ports to ensure they are not blocked.

I've always assume that these were TCP ports.  Is it possible to do the same, but use UDP instead?  Or should telnet work regardless is the listening port is TCP or UDP?
0
Comment
Question by:JamesonJendreas
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
4 Comments
 
LVL 7

Assisted Solution

by:micropc1
micropc1 earned 167 total points
ID: 37717560
Telnet runs on TCP/IP at the application layer. To my knowledge it's not possible to connect to a port using a connectionless protocol such as UDP with Telnet.
0
 
LVL 83

Assisted Solution

by:Dave Baldwin
Dave Baldwin earned 166 total points
ID: 37717623
UDP doesn't "connect", it just sends messages and doesn't not require a response.  So unless your device is programmed to respond, just sending a UDP message won't tell you anything.
0
 
LVL 41

Accepted Solution

by:
Adam Brown earned 167 total points
ID: 37717778
Telnet relies on TCP which requires a "Three-way handshake" to complete a connection. UDP doesn't do this, and so connecting to a UDP port over TCP will not complete a proper connection.

You can attempt to listen for or talk to UDP ports by using a utility called Netcat. http://netsecure.alcpress.com/netcat/ has more information.
0
 
LVL 1

Author Closing Comment

by:JamesonJendreas
ID: 37717787
Thanks all.  As I thought.
0

Featured Post

[Live Webinar] The Cloud Skills Gap

As Cloud technologies come of age, business leaders grapple with the impact it has on their team's skills and the gap associated with the use of a cloud platform.

Join experts from 451 Research and Concerto Cloud Services on July 27th where we will examine fact and fiction.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Preface There are many applications where some computing systems need have their system clocks running synchronized within a small margin and eventually need to be in sync with the global time. There are different solutions for this, i.e. the W3…
Creating an OSPF network that automatically (dynamically) reroutes network traffic over other connections to prevent network downtime.
There are cases when e.g. an IT administrator wants to have full access and view into selected mailboxes on Exchange server, directly from his own email account in Outlook or Outlook Web Access. This proves useful when for example administrator want…
Sometimes it takes a new vantage point, apart from our everyday security practices, to truly see our Active Directory (AD) vulnerabilities. We get used to implementing the same techniques and checking the same areas for a breach. This pattern can re…

623 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question