[PLUG] Vmware 2 with Ubuntu 9.10

[Vincent L. Damewood]

On Sun, Mar 21, 2010 at 6:54 PM, Daniel Herrington
<dherrington at robertmarktech.com> wrote:
> Is anyone running ubuntu 9.1 as a vmware host? I'm noticing in my test
> environment that I can't ping or ssh to any of my NAT machines. I have
> routes to the correct vmnet interface, but for some reason all the
> packets get lost.

Have you tried running a packet sniffer to be sure? Sniff on vmnet3 on
your host machine, and on eth0 on your guest.

> my guest can ping 192.168.0.2 without problems, but can't ping
> 192.168.0.1. Both ip addresses are the host machine.
> The host machine can ping 192.168.0.1, but not 192.168.0.2.

192.168.0.2 is *not* your host machine. See the comment below about
how VMware's NAT networks work for an explanation.
It would help if there was a complete listing of what systems can ping
what other systems. Being able to ping 192.168.0.1 from your host
machine indicates that the interface is working properly as an
interface. The fact that you can't ping 192.168.0.2 is suspicious, but
not useful on its own to diagnose the problem. Can your host ping your
guest? I'd make sure that firewalls on both systems are allowing ICMP
ECHO traffic through. Often times, when one system can ping another
but not vice versa, it's a firewall on the system that doesn't
respond.

> I can ssh from the guest into the host, although I can't go in the
> reverse direction.

This too sounds like a firewall issue. Check the guest's firewall to
see if it's blocking port 22.

> I'm guessing there's something missing in the routing table, but I
> compared the route outputs on my Ubuntu 8.1 Vmware server 2 hosts and
> they appear the same. Does anyone have any idea where I can begin
> looking to find the cause?

Your routing tables are fine. If it was a routing issue, your wouldn't
be able to SSH in either direction as the host wouldn't know where to
send replies.

On Tue, Mar 23, 2010 at 9:58 AM, Daniel Herrington
<dherrington at robertmarktech.com> wrote:
> The House network is running on a completely separate subnet. I have a
> clone of the guest running in the same NAT network on an Ubuntu 8.10
> host without problems. I installed Ubuntu 9.10 on test machine,
> installed VMware 2.0, then copied the guest over. I made sure to create
> the same NAT network on the Ubuntu 9.10, 192.168.0.0, and booted the
> cloned guest (CentOS 5). On Ubuntu 8.10 I can ssh from the host to the
> guest no problems.

So I understand you have two separate physical hosts each with
essentially the same exact guest OS. One host is Ubuntu 8.10, the
other is Ubuntu 9.10. The Ubuntu 8.10 functions to your expectations,
and the odd behavior is occurring on the Ubuntu 9.10 machine. Is this
correct?

> So, either the vanilla config in Ubuntu 9.10 broke the ability to ssh to
> a VMWare guest, or VMware 2.0 networking is broken on Ubuntu 9.10. I'm
> leaning towards VMware having done something, as you already have to
> patch the install to get it to work. What I'm not sure of is how VMware
> runs the NAT between the hosts IP and the guests IP. There is no bridge
> created, and the routing table looks exactly the same as Ubuntu 8.10
> except for a link-local entry in Ubuntu 9.10. I suspect the problem lies
> in the vmnet-natd, that it's not picking up any traffic into the NAT
> network.

Essentially, VMware creates a virtual network. Any system with a
virtual network adapter on that network will interact with other such
systems as if they were attached to the same Ethernet network, except
that rather than handle everything over cables, it's happening in
memory on the host system. Your host system is connected to the
network using your vmnet3 adapter as 192.168.0.1. The NAT gateway is
192.168.0.2. In addition, If a system is set to use this as its
default gateway, the packets will be NATed like any other NAT gateway
and sent our your system's physical port (or antenna). Under default
settings, whey your guest systems turn on they use DHCP to request IP
information. VMware sends the information to the systems including
using 192.168.0.2 as the default gateway.

> I'm not enough of a network guy to make sure it's not something in
> Ubuntu's 9.10 network config. That's what I'd like to verify if possible.

A lot of what you've described sounds like it could be a firewall
issue, though some things, like not being able to ping 192.168.0.2
from your host, are suspicious of a problem with the virtual network.
To figure out what the problem is, start by disabling any firewalls
you have on both systems. Also, disable SELinux on both systems. Then
try to ping from host to guest, then from guest to host. If you can
ping in both directions, things should work. Try to SSH. If it works,
then it's a problem with a firewall or SE Linux. If you can only ping
in one direction (host to guest or guest to host) but not the other,
you probably still have a firewall or instance of SELinux enabled. If
nothing works, it's probably a problem with VMware. Nothing working is
unlikely as disabling firewalls and SELinux wouldn't cause SSH to
suddenly stop working from guest to host.

Hope this helps,
Vincent Damewood