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Need help for iptables rules


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Need help for iptables rules.
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Old Unix and Linux 12-30-2016
jim mcnamara jim mcnamara is offline Forum Staff  
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tcp ports are dictated by IANA So if you decide to "secure" port 25, nobody will be able to connect using ftp.

This link has 140 pages, just read a few.
Service Name and Transport Protocol Port Number Registry

My point is: you can break all kinds of services without knowing why. And if someone attacks a random port and there is no service behind it to respond, the attacks fails. So no need to block it. This is why attacks go for a lot of known ports. So known ports may require a minor tweak.

Are you trying to harden your box for a reason? A lot of linux boxes have special apps to help you. What OS and version of it do you have?
uname -a will show that, so please post it.

Edit: It is not uncommon to harden a UNIX and break some applications.

Last edited by jim mcnamara; 12-30-2016 at 08:02 PM..
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