Find the answer to your Linux question:
Results 1 to 2 of 2
Enjoy an ad free experience by logging in. Not a member yet? Register.
  1. #1

    net.ipv4.icmp_echo_ignore_broadcasts = 1 - but ping works?

    Hello, i read this:

    # Ignore all ICMP ECHO and TIMESTAMP requests sent to it via broadcast/multicast
    net.ipv4.icmp_echo_ignore_broadcasts = 1
    and i checked my sysctl like this:

    # sysctl -a | grep net.ipv4.icmp_echo
    net.ipv4.icmp_echo_ignore_broadcasts = 1
    net.ipv4.icmp_echo_ignore_all = 0
    so i see its enabled in kernel?

    But why then i can ping to my server from external server and get response? What this value actually do? - Open, free and uncensorable websites, using Bitcoin cryptography and BitTorrent network

  2. #2
    Linux User
    Join Date
    Jun 2012
    SF Bay area
    The answer is in the comment in the first code block you posted. That settings only controls how the system deals with "broadcast/multicast" packets. ICMP packet that are unicast, meaning sent to one specific server, are outside the scope of the rule.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts