VMWare ESX 4/DL360 G5/Packet loss on management interface

[DominikR]

Hi,

I set up today VMWare ESXi 4.0.0 on a DL 360 G5 server. Installation went smooth but when using the vSphere Client I experinced loss of connection to the server from time to time.

I started investigation the issue and detected, that ping to the management IP address have a packet loss of around 13% (see ping plotter screenshot attached).

When using the "Test network" test from VMWare console ping fail too.

On the other hand, Ping to a running VM on the same host run very well and don't experience any loss. Also the link itself is not faulty, the server was used as a terminal server before and worked extremly well.

Has any of you seen this before?

Regards,
Dominik

[Michal Kapalka (mikap)]

hi,

did you check the firewall rules on ESX server ??

from the SSH/or local console

esxcfg-firewall -q

mikap

[u84823]

Check for duplex mismatch. If physical switch is configured manually (say 1000/F, 100/F whatever) then ESX needs to be so set as well.

Otherwise everything *must* be set to auto/auto at *both* ends.

[DominikR]

Hi Guys,

thank you for your replys.

1. Both the switch port and the NIC have auto negotiation enabled. In addition: If there would be a layer 1 issue, than I think we can savely assume that all network communications would be affected. But only the host traffic has this packet loss rates, not the traffic to the VMs over the same line.

2. I use ESX4i, under /sbin there are several esxcfg-* bins but not an esxcfg-firewall. But unless the ESX firewall has some kind of DoS protection builtin, why would it only drop 20 percent of the packets by random patterns?

Regards,
Dominik

[georgemad]

Have you tried another workstation ?
ie: is the link dropping from your workstation the ESXi.

[DominikR]

Hi,

yes I did :-). I tried three different machines as ping source.

Regards,
Dominik

[DominikR]

A supplemental: When I ping from a VM as source located on the same ESX host, not packet losses occour at the same time when packets are dropped from the outside. That means within the virtual switch - no problem. From an external host to a VM - no problem. Just from a external machine to the ESX host - packets get dropped.

Regards,
Dominik

[DominikR]

OK Guys, the solution was simple. The server has been used as a terminal server before we installed ESX. The TS was virtualized and my collegue forgot to tell me that he cloned the MAC address as well. So we had the same MAC address two times in the net. This explains why the VMs, that use unique MAC addresses on their one worked without a problem.

The conflict was resolved and now everything runs smoothly.

Regards,
Dominik

[DominikR]

Duplicate MAC address issue.