[CentOS] how to open a tcp port?

Michel van Deventer michel at van.deventer.cx
Wed Mar 3 13:05:59 UTC 2010


Hi,

> Greetings,
>
> On Wed, Mar 3, 2010 at 6:20 PM, Rajagopal Swaminathan
> <raju.rajsand at gmail.com> wrote:
>> Greetings,
>>
>> On Wed, Mar 3, 2010 at 6:10 PM, hadi motamedi <motamedi24 at gmail.com>
>> wrote:
>
>> is telnetd installed?
>>
> # yum install telnet-server telnet
>
>
>> is the telnet deamon running on machine #1?
>>
> chkconfig telnet on
>
> or
> from:
> http://www.cyberciti.biz/faq/how-do-i-turn-on-telnet-service-on-for-a-linuxfreebsd-system/
>
> [quote]
> The configuration file for telnet is /etc/xinetd.d/telnet. To enable
> telnet server you need to open this file and make sure disable = no
> read as disable = yes.
> [unquote]
>
> service xinetd restart
> or
> /etc/init.d/xinetd restart
>
Why are you telling him to install a telnetd ??
He's trying to connect to a port using telnet (client) to see if a server
is listening on it.

I doubt by the way if a missing package is the issue.
Please check first if there is a server listening on tcp 4965
netstat -ltpn | grep 4965

the output should show you which application is listening on tcp/4965
if there no output, there's nothing listening and you should fix your
application first (maybe it's not started ?).

If there's something listening on tcp/4965 you can try to use
telnet localhost 4965

to see if you can connect
or use
telnet ip.nu.mb.er 4965

if the application is only listening on a single ip.
use
iptables -L -vnx | grep 4965
to see if theres a firewall rule blocking it (or accepting) if you have
the firewall active (do you?)

Please let us knwo the outcome of these commands

    Regards,

    Michel





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