[Pacemaker] Problem with gratuitous arps in IPaddr2

[Andrew Beekhof]

On Wed, Sep 23, 2009 at 4:28 PM, Lars Ellenberg
<lars.ellenberg at linbit.com> wrote:
> On Wed, Sep 23, 2009 at 03:05:32PM +0200, Christoph Mitasch wrote:
>> Hello,
>>
>> I just read the following thread:
>> http://www.gossamer-threads.com/lists/linuxha/users/56429?do=post_view_threaded#56429
>>
>> What does this mean for the moment?
>> Is the IPaddr2 resource not working correctly at the moment on CentOS 5?
>>
>> What is the way to go at the moment?
>
> Dunno.
> but one could replace the call to /usr/lib/heartbeat/send_arp
> in IPaddr2 with calls to /usr/bin/arping,
> where arping come from the package called (in debian) iputils-arping.
>
> heartbeat send_arp:
> send_arp -i $interval_ms -r $repeat_count -p $some_pid_file $DEVICE $IP ${MAC:-auto} not_used not_used
>
> iputils-arping:
> (
> arping -U -b -c $repeat_count -w $repeat_count -I $DEVICE -s $IP $IP &
> arping -A -b -c $repeat_count -w $repeat_count -I $DEVICE -s $IP $IP &

Is this second one (with -A) really necessary?
My arping reading of the code indicates it shouldn't be.

> wait
> )
>
> should be almost functionally equivalent...

It should be more than that :-)
send_arp.linux.c is the arping code with a few changes to support the
interface exposed by the old send_arp binary.