Solved

No port 25 traffic allowed out from Ubuntu Server

Posted on 2010-11-27
1
476 Views
Last Modified: 2012-08-14
I have three Ubuntu 8.04 LTS servers that will not allow outgoing connections on port 25.

For instance, I can do the following from the command line on my server:

telnet anotherserver.com
or:
telnet anotherserver.com 23
or:
telnet anotherserver.com 80

but I cannot do the following:
telnet anotherserver.com 25

I get:
Trying 111.222.333.444
telnet: Unable to connect to remote host: No route to host

This is true on all three 8.04 servers I have, but there is no problem on the 9.04 or 10.04 servers. It does not make a difference if I use sudo telnet. Two of these servers are running Postfix, the third is not (if that matters). I do not see anything in IPTABLES to prevent port 25 traffic, but it does look like port 25 traffic is being selectively blocked or rerouted somehow.

Where should I look next?

Thanks.







0
Comment
Question by:jbbarnes
1 Comment
 

Accepted Solution

by:
jbbarnes earned 0 total points
ID: 34221688
It suddenly occurred to me that it might be the hosting service. Indeed, godaddy does block port 25 traffic and requires you to use a smart host. That answers it.
0

Featured Post

U.S. Department of Agriculture and Acronis Access

With the new era of mobile computing, smartphones and tablets, wireless communications and cloud services, the USDA sought to take advantage of a mobilized workforce and the blurring lines between personal and corporate computing resources.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
php ssh2_scp_send 1 46
issue in getting eth0 IP in oracale virtual box Linux VM 4 42
nagios 4 php error after installation 6 73
networking details on centos 6.6 4 49
I am a long time windows user and for me it is normal to have spaces in directory and file names. Changing to Linux I found myself frustrated when I moved my windows data over to my new Linux computer. The problem occurs when at the command line.…
Fine Tune your automatic Updates for Ubuntu / Debian
Learn how to navigate the file tree with the shell. Use pwd to print the current working directory: Use ls to list a directory's contents: Use cd to change to a new directory: Use wildcards instead of typing out long directory names: Use ../ to move…
Get a first impression of how PRTG looks and learn how it works.   This video is a short introduction to PRTG, as an initial overview or as a quick start for new PRTG users.

919 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

Need Help in Real-Time?

Connect with top rated Experts

20 Experts available now in Live!

Get 1:1 Help Now