Stopping ping for all IP's

Discussion in 'Security' started by joujoba, Dec 9, 2010.

  1. #1
    hello

    is it good or bad to stop all incoming pings to my server..
    your recommendation please?
     
    joujoba, Dec 9, 2010 IP
  2. FavouritesBlog

    FavouritesBlog Peon

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    #2
    Why would you want to do such a thing? Paranoid?
     
    FavouritesBlog, Dec 10, 2010 IP
  3. madaboutlinux

    madaboutlinux Member

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    #3
    Well, it's one of the security measures to disable ping on the server. You can write a iptable rule to block all the ICMP request coming to your server.
     
    madaboutlinux, Dec 11, 2010 IP
  4. joujoba

    joujoba Peon

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    #4
    yes a little, and why not disable it if it doesnt hurt the server surfing and functions
    so does it hurt?
     
    joujoba, Dec 12, 2010 IP
  5. elicitservers

    elicitservers Peon

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    #5
    It doesn't hurt but people may think it's offline when really it isn't. What I would do if I were you is rate limit about 1 ping/second, so that traditional ping tests work correctly, but will rate limit anything trying to ping faster than once every second. You can do this using iptables, or csf as well if you use this.
     
    elicitservers, Dec 12, 2010 IP
  6. sagemore48

    sagemore48 Peon

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    #6
    in my way,or u should the meaning of PING first.well here goes @ 【en wikipedia org/wiki/Ping】--[.] would be necessary after the [en] and the [wikipedia].sorry for this.the forum rule.

    hope ro help u.
    good day!
    sage
     
    sagemore48, Dec 14, 2010 IP
  7. ramnet

    ramnet Peon

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    #7
    Blocking ping doesn't do anything for server security.

    The only use blocking ping could serve as a security measure is to prevent people finding your server - and if your server offers public services (say, ftp, http or email) then blocking ping doesn't accomplish anything except make network troubleshooting harder if there is a problem in the future.

    ICMP is way, way more than "traceroute" and "ping." It is used for feedback when you run a DNS server (port unreachable) which, in a modern DNS server, may actually help select a different machine to query faster.

    ICMP is also used for path MTU discovery. Chances are your OS sets "DF" (don't fragment) on TCP packets it sends. It is expecting to get an ICMP "fragmentation required" packet back if something along the path fails to handle that size of packet. If you block all ICMP, your machine will have to use other fallback mechanisms, which basically use a timeout to detect a PMTU "black hole" and will never optimize correctly.

    Additionally, you should ask yourself why you want to block ICMP. What specifically are you attempting to prevent here? It's pretty clear you don't understand what ICMP is used for, which is rather common. I'd be extremely cautious in blocking something you don't fully understand.

    To make it even harder to learn about this, many common firewall books say "block ICMP" -- it's clear their authors have never read an RFC or had to solve issues surrounding such advice. It's bad advice to block all ICMP.

    Now, rate limiting it can also hurt. If your machine is busy, or even if it's not, you can get a good amount of ICMP traffic. My web server probably gets about 10-100 ICMP packets per minute, most of which is PMTU discovery. Even if someone chose to attack my server with ICMP packets of some type, it's really not that big of a deal. If your machine accepts even one TCP connection (ssh, http, mail, etc) chances are that's a bigger attack vector than misunderstood ICMP ever will be.
     
    ramnet, Dec 17, 2010 IP
  8. jarrodw

    jarrodw Peon

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    #8
    If you are on Linux try this:

    sudo iptables -A INPUT -i any -p icmp -j DROP

    iptables -A INPUT -p icmp -j DROP

    That will block all pings.


    If you need a sys admin PM my rates are good.
     
    jarrodw, Dec 30, 2010 IP