Thanks all for the feedback about our problem.
In examining this a little further, I think I stumbled upon a fix but I
don't fully understand why it works.
Since we are using IP tunneling, we had set the interface tunl0 to the VIP.
ifconfig tunl0 <VIP> netmask 255.255.255.255 broadcast <VIP>
If instead we set tunl0 to another IP (i.e. the Real Server IP) and then
create an alias of tunl0 and set that to the VIP, the problem seems fixed.
ifconfig tunl0:0 <VIP> netmask 255.255.255.255 broadcast <VIP>
The problem had been that we occasionally would get page not found errors on
our clustered Web server (Red Hat 6.2, kernel 2.2.14 on the director and two
real servers). We didn't see the error consistently, which had us looking at
different browsers etc. The error seemed to only occur on IE.
In looking at the description of the arp problem, it struck me that we might
be experiencing some flavor of that. I noticed we had overlooked in the arp
problem description <http://www.linuxvirtualserver.org/arp.html> of first
bringing up tunl0, then hiding the arp, and then configuring a tunl0 alias
to respond to the VIP.
As I said, this seems to work, but I don't understand why the alias is
necessary -- which makes me wonder whether I actually fixed something or
UMass Boston Webmaster
> From: "Zachariah Mully" <zmully@xxxxxxxxxxxxxx>
> Reply-To: lvs-users@xxxxxxxxxxxxxxxxxxxxxx
> Date: Mon, 27 Aug 2001 17:01:11 -0400
> To: <lvs-users@xxxxxxxxxxxxxxxxxxxxxx>
> Subject: RE: 404 errors running an LVS-Tun
> I had this problem when we set up our LVS-DR system, but it wasn't LVS
> that was causing this, it was Tomcat taking it's merry time to compile
> our JSP pages. We've since started to pre-compile all our JSP pages on
> the RS's before turning them up. That seemed to have fixed our problem.
> P.S. We're running 2 RS's, both RH7.1, 2.4.5 kernel, apache 1.3.20
> mod_jk with tomcat 3.2.3, the director is also RH7.1, 2.4.5 kernel, with
> two virtual hosts.
>> Has anyone ever heard or seen something like this? I'm trying
>> to figure out
>> whether the problem is a DNS issue (we recently changed the
>> DNS information
>> for the Web site), an issue with LVS or a browser based issue
>> (all sorts of
>> cache configurations on the browser seem to do no good).
>> To hide the ARP we have used the following commands on the
>> real servers:
>> echo 1 > /proc/suys/net/ipv4/conf/tunl0/hidden
>> echo 1 > /proc/suys/net/ipv4/conf/all/hidden
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