iptables - block localhost?

Discussion in 'Server Operation' started by rusty, May 21, 2010.

  1. rusty

    rusty New Member

    I have this line in my iptables:

    -A INPUT -s 123.20.0.0/12 -j DROP

    And if I do an "iptables -L", I get this:

    DROP all -- localhost/12 anywhere

    So i have two questions:

    1) Is this class B being blocked?

    2) Am I blocking anything within my own machine?

    Thanks in advance for any replies!!!
     
  2. clucian

    clucian New Member

    What is your policy default in iptables ACCEPT or DROP ?

    1 ) No

    I recomand you to use comand "iptables -nvL" to se more verbose.

    Do not block localhost, use

    iptables -A INPUT -i lo -j ACCEPT
     
  3. rusty

    rusty New Member

    My policy is to deny all, add exceptions as necessary.

    The n switch (numeric) was VERY helpful. Thank you!

    Is it correct that it is the numeric value iptables is using, not the domain name (assuming that I am blocking an IP address of course)?

    I'm not blocking localhost, iptables is doing a reverse DNS lookup and inserting that value in place of the "numeric" IP address. In other words, the Chinese class A reverse lookup result was "localhost". Today I just checked and it is something different.
     

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