Traffic Export strips off FCS header

Version 1
    This document was generated from CDN thread

    Created by: Jiasi Li on 24-03-2011 12:29:58 PM
    We are applying the traffic export profile to funnel packets from the router interface to a VM in the SRE.  After capturing the exported frames; it looks like the 4-byte Frame Check Sequence is not included.  Is there a way to include those bytes?  If not, does Cisco publish anything to address this issue?
     
    Below is a snippet of our export profile:
     
    ip traffic-export profile g01_wan
      interface Vlan1
      bidirectional
      mac-address 000c.295e.9301
     
    interface GigabitEthernet0/1
     ip address 10.250.64.85 255.255.248.0
     ip traffic-export apply g01_wan
     duplex full
     speed 100

    Subject: RE: Traffic Export strips off FCS header
    Replied by: Brett Tiller on 05-04-2011 02:34:00 PM
    Hi Jiasi,

    We are checking with our IOS team regarding this matter.  We'll get back to you once we have an answer.

    Thanks,

    Brett

    Subject: RE: Traffic Export strips off FCS header
    Replied by: Jiasi Li on 07-04-2011 04:59:50 PM
    Hi Brett,

    We are seeing this issue in our

    2911 Router
    flash:c2900-universalk9-mz.SPA.151-3.T.bin
    SM-SRE-900-K9
    Cisco SRE-V Software 1.0.1

    and

    3945 Router
    flash:c3900-universalk9-mz.SPA.151-3.T.bin
    SM-SRE-900-K9
    Cisco SRE-V Software 1.0.1

    Thanks

    Subject: RE: Traffic Export strips off FCS header
    Replied by: Brett Tiller on 07-04-2011 04:41:05 PM
    Hi Jiasi,

    For tracking purposes,  I need to know what router you are using and the service module as well.  Please provide this information.

    Thanks,

    Brett

    Subject: RE: Traffic Export strips off FCS header
    Replied by: Brett Tiller on 07-04-2011 04:49:15 PM
    Hi Jiasi,

    Please also let us know of the IOS image you are using on the router.  You can get this name by typing on the router 'show version | sec image'.

    Thanks,

    Brett

    Subject: RE: New Message from Jiasi Li in Service Ready Engine Virtualization - Tech
    Replied by: Brett Tiller on 12-04-2011 02:14:25 PM
    Hi Jiasi,



    Thanks for the data.  We have a couple of more requests.



    1.       Please send us your pcap files from which you determined that the FCS bytes are being dropped.



    2.       For our tracking records, what is the name of your company?



    Thanks,



    Brett

    Custom Application Engineer

    http://developer.cisco.com/web/axp <http://developer.cisco.com/web/axp>

    http://developer.cisco.com/web/srev <http://developer.cisco.com/web/srev>



    From: Cisco Developer Community Forums [mailto:cdicuser@developer.cisco.com]
    Sent: Thursday, April 07, 2011 2:00 PM
    To: cdicuser@developer.cisco.com
    Subject: New Message from Jiasi Li in Service Ready Engine Virtualization - Technical Questions: RE: Traffic Export strips off FCS header



    Jiasi Li has created a new message in the forum "Technical Questions":

    --------------------------------------------------------------
    Hi Brett,

    We are seeing this issue in our

    2911 Router
    flash:c2900-universalk9-mz.SPA.151-3.T.bin
    SM-SRE-900-K9
    Cisco SRE-V Software 1.0.1

    and

    3945 Router
    flash:c3900-universalk9-mz.SPA.151-3.T.bin
    SM-SRE-900-K9
    Cisco SRE-V Software 1.0.1

    Thanks
    --
    To respond to this post, please click the following link:

    <http://developer.cisco.com/web/srev/forums/-/message_boards/view_message/3554086>

    or simply reply to this email.

    Subject: RE: Traffic Export strips off FCS header
    Replied by: Brett Tiller on 19-04-2011 02:32:26 PM
    Hi Jiasi,

    Our engineering team was not able to reproduce this issue. Please review the details below.

    I checked the code no where FCS byte has been stripped off. In code packet will be cloned and dst_mac will be changed to MAC address given while configuring export.

    And also I did try export in my lab. This issue is not seen. Actually In order to see FCS byte in wireshark we need to enable the FCS byte and decode the packet 802.11. please find the settings to be done in wireshark for the same:
    1) Edit -> Preference -> Protocol -> IEEE802.11 -> check "assume packets have fcs"
    2) once packets are captured , right click on the any packet and select decode-> link(tab) -> iee802.11

    Thanks,
    Brett