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vmxnet3 vSphere 6.7 wireshark stops capture traffic

asked 2020-09-24 09:59:37 +0000

AntexMv gravatar image

Dear Community Please advise. Wireshark 3.3.0 installed to VM vmware 6.7 NIC - vmxnet3 10Gb Wireshark installed normally and seems works. But it is STOPs to catch traffic after 10-30 sec Just starts, capture a bit and stops catching. GUI works but traffic not arrive to main window Thank you much in advance Regards, Andrii [email protected]

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Wireshark will use dumpcap in the background for the packet capture. Can you make a capture from the command line using dumpcap and does it have the same issue?

Chuckc gravatar imageChuckc ( 2020-09-24 14:53:23 +0000 )edit

Dear Chuckc Thank you for your attention to my question I will try to check with dumpcap when come back to work On other hand, I read that npcap or winpcap should be used in virtual environment Also we need to take in consideration vmxnet is 10Gb vnic I also found that vmware support recommend to use internal capture tools Please correct if I am wrong Thank you for your support Regards, AntexMv

AntexMv gravatar imageAntexMv ( 2020-09-24 19:40:51 +0000 )edit

Capturing and Tracing Network Packets by Using the pktcap-uw Utility
Looks like pktcap-uw is tightly integrated and very flexible.

For detailed analysis of captured packets, you can save packet content from the pktcap-uw utility to files in PCAP or PCAPNG format and open them in Wireshark.

The default output format is pcap. When using --ng for pcapng it added a packet comment to each packet (example):

Frame 9: CAPPT PortInput TSO 0 CSUM 1 CSUMVFD 0 ENCAP 0 SEGS 2 [ 54 96 ]
Chuckc gravatar imageChuckc ( 2020-09-24 22:06:17 +0000 )edit

I will try to check with dumpcap when come back to work On other hand, I read that npcap or winpcap should be used in virtual environment

Yes, dumpcap, which is the packet capture utility that comes with Wireshark, does use WinPcap or Npcap, depending on which one you have installed. Which one do you have installed?

Using dumpcap remove all the extra Wireshark code from the code path when capturing, so that it'd be easier to see whether the problem is in dumpcap, Wireshark, or WinPcap/Npcap.

Guy Harris gravatar imageGuy Harris ( 2020-09-24 22:09:25 +0000 )edit

Dear Chuck Thank you for your support I checked dumpcap alone without wireshark I check under Administrator credentials, also using CLI and GUI In all cases behavior the same - few seconds catching traffic and stops Any idea ? Regards, AntexMv

AntexMv gravatar imageAntexMv ( 2020-09-27 05:51:19 +0000 )edit

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answered 2020-09-27 14:35:10 +0000

Chuckc gravatar image

Appears that capture is working and it is a storage problem.
Storing large captures to esxi OS partitions is probably not good.
/tmp is 256M which matches when capture ends in the last comment above.

[[email protected]:~] vdf -h | tail -10
-----
Ramdisk                   Size      Used Available Use% Mounted on
root                       32M        2M       29M   7% --
etc                        28M      184K       27M   0% --
opt                        32M        0B       32M   0% --
var                        48M      340K       47M   0% --
tmp                       256M       64K      255M   0% --
iofilters                  32M        0B       32M   0% --
shm                      1024M        0B     1024M   0% --
hostdstats                569M        3M      565M   0% --


Using /scratch is a better practice. The article below works through verifying the current location and how to configure if not present. If on a datastore check available space and configure total capture size to not overfill.
Creating a persistent scratch location for ESXi 7.x/6.x/5.x/4.x
"VMware recommends that ESXi has a persistent scratch location available for storing temporary data including logs, diagnostic information, and system swap."

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Dear Chuckc 1)Thank you much for your attention and help I will try to implement those feature ASAP (Need to arrange services temporarily stop and reboot host) 2) What would you recommend regarding Wireshark in this case ? Any setting which also allows to direct output to /scratch (or other location as Wireshark installed to VM ) And how to achieve data rotation to avoid overfilling ? Regards, AntexMv

AntexMv gravatar imageAntexMv ( 2020-09-29 04:02:48 +0000 )edit

Set the Output File location in the Capture Options:Output.

Chuckc gravatar imageChuckc ( 2020-09-29 04:59:16 +0000 )edit

Thank you Chuckc for your help But it does not help Seems capturing packet on VM is even not possible with Wireshark and nobody can solve this issue Anyway, thank you for your support Regards, AntexMv

AntexMv gravatar imageAntexMv ( 2020-09-30 08:20:59 +0000 )edit

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Asked: 2020-09-24 09:59:37 +0000

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Last updated: Sep 27