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Access network design for branch, remote, outdoor, and campus locations with HPE Aruba Networking access points and mobility controllers.
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How to capture 802.1q packet in the trunk ports?

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  • 1.  How to capture 802.1q packet in the trunk ports?

    Posted May 14, 2015 07:33 AM

    Hi guys,

     

    I was trying to capture a 802.1q packet from a trunk port,but it wasn't successed.

     

    My topology is PC---SW(aruba 1500)--controller(3600).

    From PC to SW is access port which belongs to VLAN 10; from SW to controller is trunk port which allows all the vlans.

    Also I set 2 SVIs in the SW,interface vlan 10 = 192.168.10.1/24, interface vlan 20 = 192.168.20.1/24.

    The PC's IP address is 192.168.10.2/24,its gateway is 192.168.10.1.

    In the controller,I set a SVI which is interface vlan 20,IP address is 192.168.20.2/24,

     

    For now, I can easily ping 192.168.20.2(the IP address of controller) from PC side, but when I captured the ICMP packets from the trunk port, it only showed ethernet II protocol and IP protocol, and nothing between them.

     

    The three ways I used to capture the packet:

    1,Mirroring the trunk interface in controller.

    2,Mirroring the trunk interface in SW.

    3,Add a hub between the SW and controller.

     

    Also I tried to change the setting of my NIC card,enable vlan tagging or disable it.

     

    Please someone tell me, where am I wrong?

     

    PS:I can capture the 802.1q packet from the GNS3 with the CIsco IOS.

     



  • 2.  RE: How to capture 802.1q packet in the trunk ports?

    EMPLOYEE
    Posted May 14, 2015 07:36 AM
    Most laptops cannot see 802.1q headers. Best bet is to use the packet-capture command in the controller because it will encapsulate into GRE and preserve the headers.


    Thanks,
    Tim


  • 3.  RE: How to capture 802.1q packet in the trunk ports?

    Posted May 14, 2015 07:40 AM

    I can see the 802.1q header for GNS3,same laptop.

    And I didn't use wireless,this is all wired.



  • 4.  RE: How to capture 802.1q packet in the trunk ports?

    EMPLOYEE
    Posted May 14, 2015 07:41 AM
    For GNS3, are you capturing your physical NIC or a virtual interface?


    Thanks,
    Tim


  • 5.  RE: How to capture 802.1q packet in the trunk ports?

    Posted May 14, 2015 07:58 AM

    Yes,from the real NIC card,I can see the 802.1q tag.

     

    You can see the ICMP traffic from 192.168.10.2 to 192.168.20.2.



  • 6.  RE: How to capture 802.1q packet in the trunk ports?

    EMPLOYEE
    Posted May 14, 2015 08:04 AM
    I would still just use the packet-capture command.


    Thanks,
    Tim


  • 7.  RE: How to capture 802.1q packet in the trunk ports?

    Posted May 14, 2015 08:12 AM

    Could you please tell me more about this command?

     Then I can try it tomorrow,thanks.



  • 8.  RE: How to capture 802.1q packet in the trunk ports?

    EMPLOYEE


  • 9.  RE: How to capture 802.1q packet in the trunk ports?

    Posted May 14, 2015 08:28 AM

    Is that port mirririong ?

    If so, I have already tried.Both controller side and SW side.