WHISKEYTANG0F0X
Contributor
Contributor

How to troubleshoot intermittent network problems with guest in ESXi 5?

We are having a problem with a guest dropping network connection intermittently, an i was wondering how to troubleshoot the network issues with the virtual network cards.

Our system is a PowerEdge 2950 running ESXi 5, with the latest VMWare tools installed in the OS. There are 2 different physical NICs going to 2 different switches, for 2 different networks.

Network 1 is 10/100 - 192.168.1.x

Network 2 is 1000 - 10.10.10.x

There are 2 guests installed; a BES server running on Server 2008 std 32bit, and a terminal server running on Server 2008 std x64.

Monitoring from a remote machine on both networks, the terminal server will drop 8 packets on both interfaces, while the BES server will drop nothing on both.

Here is a diagram of my network config in ESXi

1988758.png

I did not see any errors in the host performance logs when measuring, nor did I expect any as the BES server is unaffected, but I did see dropped packets on one of the terminal server guest interfaces.

1988758_1.png

There are no clues in the Windows event logs as to the cause of the drops, just consequences of them. Performance monitor on the terminal server show packet errors inbound and outbound on both interfaces never go above zero. Seven drops today affecting all terminal users.

Any ideas on how to troubleshoot error on the guest that is using the vmnics?

Thx

Brad

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8 Replies
WHISKEYTANG0F0X
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Bump?

Still having the problem, but I am noticing in the guest's performance graphs, everything flatlines for the duration of the outage except memory usage.

CPU, datastore, disk, network, virtual disk all drop to zero, then bounce back up as and return to their respective states as soon as the 8 second outage has passed.

Monitoring the other guest on the same ESXi host shows no break in the performance pattern, nor any connectivity in the same time frame.

Because this happens intermittently without warning, I am not on the console of the guest at the time to see if I experience any freezing there.

This is a terminal server affecting 50 remote users, and has been in operation for a year running on ESXi 4.1 without any problems. I can't be sure if the change to ESXi 5 coincided with the guest problem or not, as I am not 100% sure when the problem started.

Thanks,

B

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edanono
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Did you ever find a solution for this? Or at least a better to way to monitor traffic to track down the problem?

Thanks,

Tony

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StateOfTheArb
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Contributor

Any one sorted this?  I have exactly the same problem except I have a single VM on ESXi 5.1 (Dell version) and it randomly drops the connetion for about 8 sec or so.  No events in Server 2008 R2 or ESXi.  Im at a loss and reverting back to v5.0 now.

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StateOfTheArb
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Whiskey, are you running 5.0 or 5.1?

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edanono
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StateoftheArb, have you gone back to 5.0? Did that or anything else help you with that problem? I have found this on the server at the same time as the outage:

The description for Event ID ( 5050 ) in Source ( IAS ) cannot be found. The local computer may not have the necessary registry information or message DLL files to display messages from a remote computer. You may be able to use the /AUXSOURCE= flag to retrieve this description; see Help and Support for details. The following information is part of the event:

Any help with this would be great as I have people hounding me daily to fix this problem.

Thanks,

Tony

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StateOfTheArb
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hey edanono,  i actually reverted back to 4.1 and now its running perfectly.  Its def a bug with 5.1 (i didnt try 5.0, didnt have enough time) and Dell

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edanono
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Thanks for the tip. Were you able to downgrade to 4.1 without reinstalling the client? I have 30 users live on my system. It also seems like mine may be a network issue. I have 2 servers in the same rack that appear to be disconnected at the same time.

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StateOfTheArb
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unfortunately not, i copied the VM's off the host, formatted the host and reinstalled with 4.1.  And then used VMware converter to convert the VM from 5.1 to 4.1. took my an antire night to do and I was finished when I heard the birdies sing the next morning Smiley Happy

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