[impdev] Internal networking problem?

[David Seikel]

G'day.

I'm seeing what I think is an internal network problem between three of
your servers.  A fourth server also seems to have the problem, but I
can't check it directly.  All these servers are YISP servers, in your
Amsterdam data centre.  It's entirely possible this problem is
affecting servers I have no dealings with.

My server is running a 3D virtual world.  Three other servers rented by
other people are involved in part of this virtual world as well. Two of
those other servers I help to run, with the help of the person that
rents the other fourth server.  This other person is unavailable right
now.  I'm an experienced Linux sys admin, as is the renter of the
fourth server.  The other two are not, which is why we deal with the
problems of this nature on their behalf.

Approximately two to five minutes apart, there is a 30 second delay in
the networking between these servers.  I first noticed the problem in
the monitoring software claiming that there was loss of connection a
bunch of times during the day.  I investigated when I was able to.
Pings are showing the problem.  When the slow ping coincides with the
monitoring software's networking check, the problem turns up in it's
logs. And I get sent messages that something is wrong.

It does not matter which of these servers is pinging the others, at the
same time each of them will report this 30 second ping.  At the same
time, a ping from outside your network (my location on another
continent) is reporting normal ping times.  When the 30 second ping is
not happening, I'm seeing the expected ping times.

Virtual worlds are real time 3D simulations, and this real time nature
makes 30 second delays between the servers very noticeable.  This is how
I was able to check that the problem was affecting that fourth server.
I went to that part of the virtual world that fourth server is
responsible for simulating, and sure enough, at the same time those
other servers reported 30 second pings, that section of the virtual
world stopped for 30 seconds.

My server is the main server in this group.  The others just run small
sections of the virtual world.  The problem is not showing on external
connections, but showing on all the internal connections between these
four servers.  It's the internal connections to the main server that
are resulting in delays in world.  Being in other parts of the virtual
world is not a problem, the pings from them to clients are fine.

Sooo, looks like some sort of internal networking problem in your data
centre to me.

The IPs of these servers are - 46.182.105.104, 46.182.107.98,
46.182.107.9, and 46.182.107.28.
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