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Old 02-21-2022, 01:20 PM   #1
zvivered
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Send TCP message from client to server via firewall


Hello,

I admit-This is a very basic question.

My x86 server is running linux (e.g centos 7.x)
In this server, firewall is enabled.

How can a client application running in another PC can send messages (TCP) to this server ?

Using firewall configuration, I can exclude a specified port in the server from the firewall.

Is this the only way ?

Thank you,
Zvika
 
Old 02-21-2022, 02:07 PM   #2
uteck
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You can exclude a port, or you could put in a rule to allow an IP through the firewall, or even just the MAC address if the IP may change.
 
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Old 02-21-2022, 05:28 PM   #3
TB0ne
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Quote:
Originally Posted by zvivered View Post
Hello,
I admit-This is a very basic question.

My x86 server is running linux (e.g centos 7.x) In this server, firewall is enabled. How can a client application running in another PC can send messages (TCP) to this server?
Using firewall configuration, I can exclude a specified port in the server from the firewall. Is this the only way ?
Again, as a 'kernel developer' for the past 15 years, it's very odd that you seem to lack basic knowledge.

Your question of, "how can a client application send messages over TCP" is answered with, "By *WRITING A PROGRAM TO SEND DATA OVER TCP*". But again, you provide NO DETAILS about this mystery application, what kind/how much data it needs to send, over what TCP port, using what protocol. Opening a port doesn't do ANYTHING beyond letting data get through...you need a program to listen on that port, and another program on the other end to SEND. Opening a port doesn't do anything magical, or make whatever code you write work over a network if you haven't already coded it to do so.

Since you're an 'experienced developer', who has written kernel modules for custom embedded hardware, it should be trivial for you to write a client/server type application.
 
Old 02-22-2022, 01:12 AM   #4
zvivered
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Hi uteck,

Thank you very much !
In what scenario should I use IPSEC ?

Best regards,
Zvika
 
Old 02-22-2022, 07:55 AM   #5
TB0ne
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Quote:
Originally Posted by zvivered View Post
Hi uteck,

Thank you very much ! In what scenario should I use IPSEC ?
*AGAIN*
  • IPSEC has zero to do with a firewall, or a client/server communications program. IPSEC is a VPN.
  • Opening a firewall port will only let a data through that port...it doesn't magically make your program communicate.
  • *YOU, PERSONALLY* will have to write code to do this.
You are *STILL* providing zero details about ANYTHING...as you've been told many, MANY times over the past 15 years, without details we can't tell you much. You are not saying how much data, how you want to send it, what you've done/tried, what programming languages, what kind of connection (LAN? Internet? VPN (now that you mention IPSEC)), etc. We aren't going to guess.

If you're not going to bother to answer questions or acknowledge things, there isn't a point in posting. Again, you claim to be a 'kernel developer' working on custom embedded hardware, with 15 years programming experience, but can't seem to do things like load a kernel module or understand the basics of networking. Very odd that someone with your supposed skill-set is having problems with such things.
 
Old 02-22-2022, 09:10 AM   #6
uteck
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It sounds like you are taking a test and are fishing for answers here. Post your question is Google for faster results.
 
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Old 02-22-2022, 02:31 PM   #7
TB0ne
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Quote:
Originally Posted by uteck View Post
It sounds like you are taking a test and are fishing for answers here. Post your question is Google for faster results.
Sadly, I don't think that's the case.
 
  


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