[Linux-ha-dev] problem shutting down first createdaliasinterfaces on linux

[Sebastian Reitenbach]

Dejan Muhamedagic <dejanmm at fastmail.fm> wrote: 
> Hi,
> 
> On Fri, Jan 11, 2008 at 04:56:46PM +0100, Sebastian Reitenbach wrote:
> > Dejan Muhamedagic <dejanmm at fastmail.fm> wrote: 
> > > Hi,
> > > 
> > > On Fri, Jan 11, 2008 at 01:39:28PM +0100, Sebastian Reitenbach wrote:
> > > > Hi,
> > > > 
> > > > I stumbled across a strange behavior of ifconfig/ip, regarding alias 
IP 
> > > > addresses on linux. I found this behaviour on suse 10.1, 10.2, 10.3 
and 
> > > > SLES10SP1.
> > > > 
> > > > When you configure multiple aliases on an single interface, and you 
> > specify 
> > > > netmasks and broadcasts, and then try to shutdown just the first 
created 
> > > > alias then all IP aliases for that interface will be gone. Removing 
one 
> > of 
> > > > the later created aliases works as expected.
> > > > 
> > > > As I think virtual IP aliases are used often in HA environments, it 
> > might be 
> > > > of interest to you. 
> > > > 
> > > > here is more information:
> > > > https://bugzilla.novell.com/show_bug.cgi?id=352841
> > > 
> > > A strange and frightening bug. I wonder how it went unnoticed
> > > this long.
> > yeah, me too. I uploaded a testscript to the bugreport, You can test 
whether 
> > it happens to you too. at least I have it seen on any suse version I 
have 
> > around here... 
> 
> It does on the openSUSE 10.3 as well as on Debian Etch. But, as
> Lars pointed out, only if a new netmask is defined.
yes, and that might be the reason why it was not yet noted.

> 
> BTW, looking a bit around, it seems like there were similar
> problems in the past.
I choose a different network than the physical interface has, because I just 
did not wanted to interfere with maybe existing addresses. I just had the 
script for testing purposes, in production my aliases will be from the same 
subnet, so I will not have the problem.
But maybe there are people that need to configure their aliases that way, 
and these will then face that problem.

cheers
Sebastian