Hi all,
I am brand new to Linux, playing around a bit with different things to see how I can use it in the future. Here is my problem:
I have written a simple program in Ada that works well on windows. It opens a TCP port (20000) and listens for incoming connections. I tried it on my internal network and it works well. I can connect from other windows machines and even from my Linux machine.
Now I moved the program to Linux and compiled it there. It starts ok and then listens for the connections. I can connect to it from that same Linux machine but not from any other machine on my network.
I checked the firewall status on Linux with ufw status and it is disabled. I also tried to add a rule to the iptables with
iptables -A INPUT -p tcp --dport 20000 -j ACCEPT
but still nothing. I can not connect from another machine on my network. I also tried to open a simple telnet connection from a windows machine and that too is blocked. I thought without the firewall all incoming connections would be allowed but obviously something is not working as I thought.
Any help would be greatly appreciated
Good Morning! I am supporting the coffee and Doritos industry with my frustration with this problem. I have been battling it for two months. I have several Red Hat books, the official Red Hat study guide, and have searched the forums for weeks with no avail. I was wondering if you have ever had this?
I am trying to "telnet server.example.com 25" or telnet in general. Both servers are running on a KVM on the 192.168.122.0/24 network.
[root@server ~]# telnet server.example.com
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused
Trying 192.168.122.191...
telnet: connect to address 192.168.122.191: Connection refused
I can ssh, run NFS, and also run internal postfix e-mails.
IPTABLES IS TURNED OFF ON BOTH CLIENTS
Postfix and Telnet is configured on both clients, with both listening:
[root@server ~]# netstat -tulpn |grep :25
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1802/
When I Telnet from client named 'Server' to client named 'ISCSI', tpcdump on client 'ISCSI' gives the following:
19:01:23.579330 STP 802.1d, Config, Flags [none], bridge-id 8000.52:54:00:2e:85:0e.8003, length 43
19:01:23.632750 IP server.57477 > iscsi.example.com.telnet: Flags [S], seq 2403459934, win 14600, options [mss 1460,sackOK,TS val 2679191 ecr 0,nop,wscale 6], length 0
19:01:23.632882 IP iscsi.example.com.telnet > server.57477: Flags [R.], seq 0, ack 2403459935, win 0, length 0
19:01:24.428091 IP server.57478 > iscsi.example.com.telnet: Flags [S], seq 942066757, win 14600, options [mss 1460,sackOK,TS val 2679990 ecr 0,nop,wscale 6], length 0
19:01:24.428163 IP iscsi.example.com.telnet > server.57478: Flags [R.], seq 0, ack 942066758, win 0, length 0
19:01:25.006222 IP server.57479 > iscsi.example.com.telnet: Flags [S], seq 2689610466, win 14600, options [mss 1460,sackOK,TS val 2680564 ecr 0,nop,wscale 6], length 0
Hello guys, I am new to using Linux and trying to setup telnet server on CentOS 7. After installing with "yum install telnet telnet-server".
I tried editing the /etc/xinetd.d/telnet file which I could not find. Please what am I not doing right?
Hello, My issue is very common but, not able to resolve it.
Issue I am facing with my Linux (RHEL-5 32-bit) machine, where I am not able to connect to internet.
DWR-113 - D-Link Router is configured for 3G dongle (Vodafone India) - This setup is done via WiFi and not using the provided LAN cable from Win7 machine.
Internet is working absolutely fine in case of Wireless but, at same time when LAN cable is used internet is not working. [Able to ping to Router IP i.e. 192.168.0.1)
Similarly, from Linux box, ping to Router IP is working [LAN plugged] but, Internet not working. IP of linux machine: 192.168.0.60
Also, able to get the console connection of Linux from Windows box..[Windows connected to Router via WiFi and Linux connected to Router via LAN cable]
Please suggest how to get rid of this problem so that Internet will work on Linux via LAN cable.
Many Thanks,
So I'm on the last step of this article to run vmware-install.pl to start installation of my VMware tools and I'm getting this error.
[root@LinuxTest01 vmware-tools-distrib]# ./vmware-install.pl
-bash: ./vmware-install.pl: /usr/bin/perl: bad interpreter: No such file or directory.
I do a ls in the directory and it shows the installer in there.
[root@LinuxTest01 vmware-tools-distrib]# ls
bin doc etc FILES INSTALL installer lib vmware-install.pl
The only step I didnt do in this article is the prereq. first step because Yum is always trying to connect to the internet and my Centos 7 box is on a classified network with no internet access.
http://www.ehowstuff.com/how-to-inst...hel-7centos-7/
I have installed two virtual Linux(RHEL7)servers on VMWARE 11 and I need help on how to connect those servers to each other and my base machine is having windows 7 64 bit OS
So can anybody please help me out with this one
Hi,
So, I am learning meteor.js and signed up for a (cheap, i.e no support) VPS to host my Meteor app. Everything is running fine but I am trying to understand better how Linux works so here is my question:
I am running CentOS 7 on the VPS but it still uses iptables for its firewall.
I had to enable port 80 to access the web server. However, if I reboot the server, it stops working until I do
Code:
iptables -F
Then everything works. But I am thinking that -F might not be the best thing. I have changed the default SSH port from 22 to something else and that also works but I don't think I ever added it to the iptables rules.
If I do a port scan, the new SSH port is indicated as open as well as port 80 but others are closed as they are supposed to be.
Any idea what is doing on behind the scenes that requires iptables -F for the web access to work properly and if I shouldn't be doing iptables -F (I have it in the rc.local file), what is the right way of doing it?
(BTW, I am computer literate but not that familiar with Linux, which I am trying to learn now.)
Kamal
Hi
I have users that log in to our linux server using telnet. Just yesterday out of the blue, the Telnet services would automatically stop, and so I have to log in through ssh to manually start the telnet services in order for users to log in.
Thanks in advance.
*I am a linux newbie, and have taken from a guy that left abruptly so Im still trying to teach myself cmds.
I am currently working on a sbc6000x board with linux 2.6.24 on it and would like to use the telnetd command from busybox (v1.4.2).
I can run the Telnet daemon on the board and try to connect to it from another computer but each time the connection close.
In the terminal of the computer i have : (i changed the ip with Ipoftheboard here)
Trying Ipoftheboard
Connected to Ipoftheboard
Escape character is '^]'.
Connection closed by foreign host.
I already tried to use the hosts.allow file with :
ALL : Ipofthecomputer
And i checked in /etc/initd.conf and Telnet is enabled.
I read that maybe the connection is closing because i don't have a user/password configured for the Telnet connection but i can't find where to configure them.
I must use Telnet, i can't use another solution like ssh.
Hi,
I have a CentOS 6 machine [Machine X], which I connect to using a putty client or from another CentOS 6 machine.
Now, the machine X intermittently sends a connection reset message to all SSH sessions -
Code:
Read from remote host 1.1.1.1: Connection reset by peer
Connection to 1.1.1.1 closed.
I have switched off the firewall on the machine & there are no session timeout values set.
How do I find out what is causing this issue?
Thanks
Bhushan