[lkml]   [2001]   [Jan]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: Turning off ARP in linux-2.4.0
    > On Tue, Jan 23, 2001 at 01:50:27AM +0100, Bernd Eckenfels wrote:
    > > Another option is to ifconfig -arp the eth0 interface. I browsed through t
    > he
    > > IPv4 code and did not find any other goto out which can be configured besi
    > des
    > > the input FIB, which messing with is a bad thing since it wont accept the
    > > packet at all.
    > >
    > > so ifconfig -arp is the only option i could find which will help you. You
    > need
    > > to hardcode the arp entries for the real ip's of those web servers to reac
    > h
    > > them.
    > -arp means that the kernel will not put in link layer to the packets.
    > It's probably not what you want. Yes the option is misnamed.
    > 2.2 has arpfilter, which will hopefully end up in 2.4 soon too. Here is a
    > patch. It allows to filter ARP replies based on the routing table.
    > -Andi

    Thanks for the patches. I patched the kernel and tried it and it
    still is reponding to arps even after I issued:

    echo 1 > /proc/sys/net/ipv4/conf/all/arp_filter
    echo 1 > /proc/sys/net/ipv4/conf/lo/arp_filter

    I do not know what the hidden interface did exactly and I am still
    unsure why it no longer shows up in the 2.4.0 kernel.
    Here is a clip from the TurboLinux ClusterServer manual that explains
    how to turn off the arping. Maybe it will clear up what I am trying to

    Next you have to turn off ARP replies on the interface. How you
    accomplish that depends upon which Linux kernel version you are using.
    On UNIX systems and Linux 2.0 kernels, you can supply the -arp option
    to the ifconfig command when you bring up the interface. (Note that
    some UNIX and Linux systems may use a slightly different syntax, such
    as using noarp instead of -arp.) So in our example, we would use this
    command to configure the interface:

    # ifconfig lo:1 netmask -arp

    Unfortunately, this method does not work in any Linux kernels more
    recent than the 2.0 series. For systems running kernel 2.2.14 and higher
    the -arp option does not work. Instead, you will have to use the /proc
    filesystem to turn off ARP replies. To do this, echo a 1 to the hidden
    file in /proc/sys/net/ipv4/conf/all and the hidden file for the
    interface you are using. Here is an example that will turn off ARP
    replies on the loopback interface:

    # echo 1 > /proc/sys/net/ipv4/conf/all/hidden
    # echo 1 > /proc/sys/net/ipv4/conf/lo/hidden

    Is there something that the arp_filter can do that will mirror this
    functionality? The modification that you made to the documentation
    was pretty straight forward in that the arp_filter was BOOLEAN, so
    I think I implemented it right.

    Any other ideas?

    Thanks for your help.


    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 13:21    [W:0.023 / U:4.288 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site