Linux - SecurityThis forum is for all security related questions.
Questions, tips, system compromises, firewalls, etc. are all included here.
Notices
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
I have configured my fireall to let only EMAIL, HTTP/HTTPS and SSH traffic let through to the web server. I used the following rule
Code:
-A FORWARD -s 0/0 -i eth1 -d 192.168.1.10 -o eth0 -p TCP -m multiport --dports 80,443,110,22 -j ACCEPT
-A FORWARD -d 0/0 -o eth1 -s 192.168.1.10 -i eth0 -p TCP -m state --state ESTABLISHED -j ACCEPT
That is working fine. But when i scanned my 192.168.1.10 computer through some other machine from outside netowkr say (192.168.2.10) through nmap following command
Code:
nmap -sS -O 192.168.1.10
it showed me 2-3 extra ports which are opened i.e.
Code:
22
80
111
443
514
I don't know why 111, 514 are open. Can someone explain this?
I think it would depend on what rules you bind to your machine's interfaces. Your rules mention eth1. What about the other interfaces (if there are any)? I'd look at the services running on those ports and turn them off (they're obviously running).
For future reference, you can always check on the IANA-registered port numbers / services in /etc/services.
(Interestingly, nmap(1) does not actually query this file, though. It comes with its own list of port num / service mappings.)
Yeah, that's what I did when I saw the post. To be frank, nmap's list is probably more accurate (although anyone can edit their /etc/services file to accurately reflect the proper services).
LinuxQuestions.org is looking for people interested in writing
Editorials, Articles, Reviews, and more. If you'd like to contribute
content, let us know.