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I have a veritas backup server (windows server 2012) that I use for backup. One of the server I need to backup (Redhat Enterprise Linux 5.9) is failing to communicate with my backup server. I have checked the port that veritas backup uses , which is 10000 and did "telnet" from windows server to linux server but it failed with the following message:

connecting to ...could not open connection to the host, on port 23: connect failed

So, I checked port 10000 in linux server using netstat -apn|grep -w 10000 command and found that it is not displaying an output. Because of that, I did the following:

#iptables -I INPUT -p tcp --dport 10000 -j ACCEPT
#service iptables save
#service iptables restart

Then I tried to verify :

netstat -apn|grep -w 10000

but I am not getting any output,even though i have tried the same on a test linux server but I succeeded to open that port in test server. And the following is the output I got from the test server:

# netstat -apn | grep -w 10000
tcp        0      0 0.0.0.0:10000               0.0.0.0:*                   LISTEN      44080/beremote
tcp        0      0 :::10000                    :::*                        LISTEN      44080/beremote

Then I went to backup server and did "telnet", it succeeded and then tried to add that test server to my veritas backup...and succeeded as well.

Here is the iptables -L command output of my production linux server that failed in communicating:

# iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:10000
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:10000
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:10000
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:10000
ACCEPT     tcp  --  anywhere             anywhere            state NEW tcp dpt:10000
ACCEPT     udp  --  anywhere             anywhere            udp dpt:ndmp
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:10000
Chain FORWARD (policy ACCEPT)
target     prot opt source               destination
Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

Any idea how to open or make that 10000 port listen?

Gerald Schneider
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Mussa
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  • If the port does not show up in netstat it is not a firewall problem. The process does simply not open the port. You can grep for the PID or string "berennte" instead of the port (when running netstat as root) tomes what ports are opened by the process. – eckes May 29 '17 at 09:51
  • If `netstat` doesn't show the port, nothing is listening on it. Adding a firewall exception won't change anything about it. Make sure the process is running and configured to listen on that port. – Gerald Schneider May 29 '17 at 09:51

1 Answers1

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It seems that everything is okay but your telnet command tries to open port 23 and not 10000.

( "connecting to ...could not open connection to the host, on port 23: connect failed")

try

telnet myserver 10000

telnet will connect on port 10000 instead of port 23.

bgtvfr
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