Re: [dpdk-dev] capture packets on VM

[Raja Jayapal <raja.jayapal@tcs.com>]

Hi Reshma, 

Thanks for your information.
I have been trying to run the testpmd app and would like to get some idea on the packet flow in testpmd.

br0 -----vnet0----- (port0)VM NIC

br1------vnet1------(port1)VM NIC

br2------vnet2------(port2)VM NIC

br0 IP and MAC:
fe:54:00:0d:af:af - 192.168.100.10
br1 IP and MAC:
fe:54:00:4e:5b:df - 192.168.100.20
br2 IP and MAC:
fe:54:00:93:78:6d - 192.168.100.30

Ran testpmd application on VM and sending packets from Host using packeth.

Using PackETH generator, sent traffic from br0 destined to br1(modified the source / destination MAC and IP in packeth tool), but i could see that the packets are received on port0 and transmitted on port2.

Sending packets from br0 to br1:

./testpmd -c 3 -n 4 -- -i --total-num-mbufs=3000
testpmd> show port stats all
  ######################## NIC statistics for port 0  ########################
  RX-packets: 4          RX-missed: 0          RX-bytes:  0
  RX-errors: 0
  RX-nombuf:  0         
  TX-packets: 0          TX-errors: 0          TX-bytes:  0
  ############################################################################
  ######################## NIC statistics for port 1  ########################
  RX-packets: 0          RX-missed: 0          RX-bytes:  0
  RX-errors: 0
  RX-nombuf:  0         
  TX-packets: 0          TX-errors: 0          TX-bytes:  0
  ############################################################################
  ######################## NIC statistics for port 2  ########################
  RX-packets: 0          RX-missed: 0          RX-bytes:  0
  RX-errors: 0
  RX-nombuf:  0         
  TX-packets: 4          TX-errors: 0          TX-bytes:  0
  ############################################################################
testpmd> 

Second time, sent traffic from br1 to br2, but the packets are received on port2 and transmitted on port0.

Sending packets from br1 to br2:

testpmd> show port stats all
  ######################## NIC statistics for port 0  ########################
  RX-packets: 0          RX-missed: 0          RX-bytes:  0
  RX-errors: 0
  RX-nombuf:  0         
  TX-packets: 6          TX-errors: 0          TX-bytes:  0
  ############################################################################
  ######################## NIC statistics for port 1  ########################
  RX-packets: 6          RX-missed: 0          RX-bytes:  0
  RX-errors: 0
  RX-nombuf:  0         
  TX-packets: 0          TX-errors: 0          TX-bytes:  0
  ############################################################################
  ######################## NIC statistics for port 2  ########################
  RX-packets: 0          RX-missed: 0          RX-bytes:  0
  RX-errors: 0
  RX-nombuf:  0         
  TX-packets: 0          TX-errors: 0          TX-bytes:  0
  ############################################################################
testpmd> 

Could you please suggest whether this is expected behaviour?
Also suggest if any configuarion needs to be done to make the flow to work correctly. 


Thanks,
Raja

-----"Pattan, Reshma" <reshma.pattan@intel.com> wrote: -----
To: Raja Jayapal <raja.jayapal@tcs.com>
From: "Pattan, Reshma" <reshma.pattan@intel.com>
Date: 07/15/2016 07:33PM
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: RE: [dpdk-dev] capture packets on VM


> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Raja Jayapal
> Sent: Friday, July 15, 2016 6:55 AM
> To: dev@dpdk.org
> Subject: [dpdk-dev] capture packets on VM
> 
> Hi All,
> 
> I have installed dpdk on VM and would like to know how to capture the packets
> on dpdk ports.
> I am sending traffic from host  and want to know how to confirm whether the
> packets are flowing via dpdk ports.
> I tried with tcpdump and wireshark but could not capture the packets inside VM.
> setup : bridge1(Host)------- VM(Guest with DPDK) ----- bridge2(Host)
> 

Hi,

On DPDK you can capture packets with app/pdump/ tool. This tool is available for use from 16.07RC1. 
What you can do is run testpmd and see if packets are seen in testpmd, that confirms if packets are landing on dpdk ports or not.
If you also want to capture packet for analysis, you need to run app/pdump/ tool along with testpmd. 
The pdump tool captures the packet to pcap file, so you can use tcpdump -ni <pcap file> to view the packets. 
More about the tool usage can be found under doc/guides/sample_app_ug/pdump.rst

Let me know if you need further help on this.

Thanks,
Reshma


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