LinuxQuestions.org
Share your knowledge at the LQ Wiki.
Home Forums Tutorials Articles Register
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Security
User Name
Password
Linux - Security This forum is for all security related questions.
Questions, tips, system compromises, firewalls, etc. are all included here.

Notices


Reply
  Search this Thread
Old 05-14-2022, 12:52 PM   #1
mtdew3q
Member
 
Registered: Mar 2006
Location: the next town over from siberia
Distribution: xubuntu
Posts: 481

Rep: Reputation: 18
I don't understand why this port rule in firewalld


Hi guys-

Just wondering, why the command to leave ports 1025-65535 open as a rule in firewalld. There is an article that they brought to the attention of the firewall people. It was under consideration.

sudo firewall-cmd --get-active-zones
FedoraWorkstation

I don't know what you guys think. I turned the port rules off.

thanks,
roboloki
 
Old 05-14-2022, 12:55 PM   #2
mtdew3q
Member
 
Registered: Mar 2006
Location: the next town over from siberia
Distribution: xubuntu
Posts: 481

Original Poster
Rep: Reputation: 18
https://pagure.io/fesco/issue/1372

That is where someone is talking about the ports being opened issue.

I am not really sure.

roboloki
 
Old 05-22-2022, 06:05 PM   #3
Skaperen
Senior Member
 
Registered: May 2009
Location: center of singularity
Distribution: Xubuntu, Ubuntu, Slackware, Amazon Linux, OpenBSD, LFS (on Sparc_32 and i386)
Posts: 2,684
Blog Entries: 31

Rep: Reputation: 176Reputation: 176
ultimately, it depends on how you intend to use your network connectivity. i usually leave them open so i can make connections outbound to the internet in a trivial way, these being the typical or randomly selected source ports.

1025-65535 should be 1024-65535 unless you have a reason to leave 1024 different from the others.

someone could probe port 9216 by trying to make a TCP connection to it. if they get no response, they might assume it is blocked. if they get connection refused, they might assume many other ports are open and run a scan to see what might be listening (like databases and application servers).
 
1 members found this post helpful.
Old 05-22-2022, 06:26 PM   #4
michaelk
Moderator
 
Registered: Aug 2002
Posts: 25,760

Rep: Reputation: 5931Reputation: 5931Reputation: 5931Reputation: 5931Reputation: 5931Reputation: 5931Reputation: 5931Reputation: 5931Reputation: 5931Reputation: 5931Reputation: 5931
If I understand the question... That seems strange if those ports are specifically open as input.

Is that incoming or outgoing? Depends on how your particular distribution is configured but typically the ephemeral port range is 32768 - 60999. I have not played with Fedora much so not familiar with its default rules nor know what port range it uses but you can verify via:

Code:
cat /proc/sys/net/ipv4/ip_local_port_range 

32768	60999
Again, I would not know why the ports should be open if you are asking about incoming traffic. Any traffic that is related,established, the firewall should be able to track those ports without additional rules.

I leave a few special higher ports open < 32768 specifically for iptraf and other testing on my LAN but not open to the Internet.

Last edited by michaelk; 05-22-2022 at 06:27 PM.
 
1 members found this post helpful.
  


Reply



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
[SOLVED] If you don't understand a cmd don't do it! GPGAgent Linux - Newbie 21 12-30-2020 03:05 PM
[SOLVED] I want to add/convert an iptables rule to Firewalld RadicalDreamer Linux - Networking 4 11-15-2020 12:17 AM
Socket server security firewalld rich rule vs logwatch newbie14 Linux - Security 6 10-02-2020 10:53 AM
[SOLVED] firewalld - cannot state a rule with port range Sum1 Linux - Software 1 04-11-2018 03:04 PM
I don't understand this iptables rule -i lo Melsync Linux - Security 2 09-19-2006 06:13 AM

LinuxQuestions.org > Forums > Linux Forums > Linux - Security

All times are GMT -5. The time now is 08:43 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Open Source Consulting | Domain Registration