- Community Home
- >
- Servers and Operating Systems
- >
- Operating Systems
- >
- Operating System - Linux
- >
- Cannot telnet to a port from another server
Categories
Company
Local Language
Forums
Discussions
Forums
- Data Protection and Retention
- Entry Storage Systems
- Legacy
- Midrange and Enterprise Storage
- Storage Networking
- HPE Nimble Storage
Discussions
Discussions
Discussions
Forums
Forums
Discussions
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
- BladeSystem Infrastructure and Application Solutions
- Appliance Servers
- Alpha Servers
- BackOffice Products
- Internet Products
- HPE 9000 and HPE e3000 Servers
- Networking
- Netservers
- Secure OS Software for Linux
- Server Management (Insight Manager 7)
- Windows Server 2003
- Operating System - Tru64 Unix
- ProLiant Deployment and Provisioning
- Linux-Based Community / Regional
- Microsoft System Center Integration
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Community
Resources
Forums
Blogs
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО04-27-2010 07:42 AM
тАО04-27-2010 07:42 AM
Cannot telnet to a port from another server
Locally to the server I could enter the command and the reply would be successfull:
#telnet 172.25.6.13 9500
#telnet 172.25.6.13 9501
#telnet 172.25.6.13 9502
But when I enter those commands from another server, It doesn't work, even though I could successfully do simple telnet from any other server.
Please help !
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО04-27-2010 07:50 AM
тАО04-27-2010 07:50 AM
Re: Cannot telnet to a port from another server
Which "an application" is this?
> [...] the server [...]
Which kind of "the server" is this?
> [...] It doesn't work [...]
Which kind of "It doesn't work" is this?
As usual, showing actual commands with their
actual output can be more helpful than vague
descriptions and interpretations.
> [...] from another server [...]
How many firewalls are involved here?
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО04-27-2010 08:06 AM
тАО04-27-2010 08:06 AM
Re: Cannot telnet to a port from another server
The servers were all RHEL5 ( Red Hat Enterprise Linux version 5 )
There is no firewall involved.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО04-27-2010 10:52 AM
тАО04-27-2010 10:52 AM
Re: Cannot telnet to a port from another server
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО04-27-2010 11:33 AM
тАО04-27-2010 11:33 AM
Re: Cannot telnet to a port from another server
In the server see if any app is actually listening on those ports.
netstat -an | grep 9500
repeat for other ports.
If something is listening, proceed to check network connectivity. If not, check and see about that application. It is is either not running or not running as you expect it to run.
SEP
Owner of ISN Corporation
http://isnamerica.com
http://hpuxconsulting.com
Sponsor: http://hpux.ws
Twitter: http://twitter.com/hpuxlinux
Founder http://newdatacloud.com
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО04-28-2010 05:19 AM
тАО04-28-2010 05:19 AM
Re: Cannot telnet to a port from another server
The telnet service is running.
Here is the output of netstat:
[root@rcbbkup ~]# netstat -an | grep 9500
tcp 0 0 :::9500 :::* LISTEN
[root@rcbbkup ~]# netstat -an | grep 9501
tcp 0 0 :::9501 :::* LISTEN
[root@rcbbkup ~]# netstat -an | grep 9502
tcp 0 0 :::9502 :::* LISTEN
[root@rcbbkup ~]# netstat -an | grep 9503
tcp 0 0 :::9503 :::* LISTEN
[root@rcbbkup ~]# netstat -an | grep 9505
tcp 0 0 :::9505 :::* LISTEN
tcp 2 0 ::ffff:10.7.2.108:9505 ::ffff:10.7.2.108:17569 CLOSE_WA
IT
Please help me interpret the output and Advice .
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО04-28-2010 07:31 AM
тАО04-28-2010 07:31 AM
Re: Cannot telnet to a port from another server
> [...]
Ok. Someone is listening at that (and the
other) ports. (Which was evident from the
fact that you could use Telnet to connect to
these ports from the local system.)
> > [...] It doesn't work [...]
>
> Which kind of "It doesn't work" is this?
Still wondering...
> [...] I could successfully do simple telnet
> from any other server.
> There is no firewall involved.
Those two statements seem to disagree.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО04-28-2010 11:34 AM
тАО04-28-2010 11:34 AM
Re: Cannot telnet to a port from another server
try again
If it works then you need to either turn off the iptables or edit to include these port rules.
1 - this is all assuming that you have network connectivity from serverA to serverB
2 - this assumes that you can connect to these ports locally
3 - this assumes that you should not expect any input/output from these ports when using telnet ( simply a connection that would mostlikely just sit there returning nothing ).
done assuming ;)
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО04-29-2010 12:05 AM
тАО04-29-2010 12:05 AM
Re: Cannot telnet to a port from another server
The banking application is installed on server A. The application is working perfectly and locally to server A, I could TELNET to those ports mentioned above.
From the remote server B, I could TELNET server A, BUT from server B, I could not TELNET server A at the PORTS mentioned above.
There is no firewall between server A and server B, except that server A may be having in-built firewall or security features I don't know. The OS is RHEL5 Red Hat Enterprise Linux 5.
Please what are the settings I should check. I am very new to Linux.
Please Advice.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО04-29-2010 10:44 AM
тАО04-29-2010 10:44 AM