Topic: No http/ssh access to virtual machines from LAN

[Marco Hess]

Due to a spade of network access problems I recently reconfigured my gateway-server into server-only configuration and since then I lost the ability to access the virtual machines that are on that server from the LAN.

The strange things is that the virtual servers can be pinged from the LAN but http access (like server-manager) gets no response. Similary PuTTY access is also no longer possible. Also after a login through VMware Server Console, theses VM's can access the Internet (like for updates) and send mail (not sure about receive).

The problem exist on all PC's on the LAN and I tried with Firefox, Chrome and IE.

When I am in a shell on the server, I can use lynx to access server-manager on the VM's.

On the server using iptraf, I can see the IP link established between my PC and the VM, but the connection times out and the browser does not get a response. Same with Putty establishing a link to port 22, and then just sits there.

Initially at the reconfiguration, I bonded the two Ethernet ports and had VMware reconfigured to connect vmnet0 to the bond0 interface. Later I reconfigured again and with only one Ethernet port eth0 and reconfigured VMware again to bind to eth0. None of this makes a difference in the http/ssh access to the VM's.

At some point I thought it may have something to do with the default gateway IP on the PC's (all through DHCP) as this now points to the Internet gateway IP (10.1.0.1) and no longer to the server (10.1.0.20) so I manual reconfigured a PC to have a default gateway to 10.1.0.20 but this does not make a difference (I get lots of ICMP redirects in iptraf though).

Anybody got any idea as to how I can diagnose this further as to why I don't get a response from the VM's from a PC on the LAN?

Marco

[mmccarn]

This may be completely irrelevant, but -

I had similar behavior with Windows VM servers hosted on a Windows VM host using a network card that supported "TCP Offloading" configured in "bridge" mode.

When microsoft released windows 2003 service pack 1 or 2 (I forget which), they introduced native support for TCP Offloading, which, when activated, prevented communications between the host and guest OSs.  There were some registry mods and network card settings that were supposed to disable tcp offloading, but I never did get the guest VMs working again.

In my case, the guest machines could see "out" to any system except the host, and the host could also see anything on the network except the guest.

This was a year or two ago, using VMware Server.

[Marco Hess]

Found a possible solution to this issue and filed a bug report:

http://bugs.contribs.org/show_bug.cgi?id=5730