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show ethernet-switching statistics on EX4200

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  • 1.  show ethernet-switching statistics on EX4200

    Posted 06-20-2017 05:02

    Is there a way to check for extensive unicast flooding on an EX 4200 switch or, even better, on a single port of the switch? 

     

    Regards,

    Pawel



  • 2.  RE: show ethernet-switching statistics on EX4200

    Posted 06-20-2017 21:05

    Hi pmazurkiewicz

     

    You can configure unknown-unicast-forwarding on EX4200 to get to know more information. 

     

    https://www.juniper.net/documentation/en_US/junos12.3/topics/task/verification/rate-limiting-unknown-unicast-forwarding-verifying.html

     

    Thanks 

    Arul 



  • 3.  RE: show ethernet-switching statistics on EX4200

    Posted 06-21-2017 04:08

    Hi,

     

    Not sure if I understand you fully - if i set a port for unknown-unicast-forwarding it will stop flooding unknown unicast to other ports - possibly braking comunication... 

     

     

    Regards,

    Pawel 



  • 4.  RE: show ethernet-switching statistics on EX4200

    Posted 06-21-2017 04:18

    This is more like a security feature. 

     

    When you configure unknown-unicast forwarding for a VLAN and destine it to a interface, no matter what port the traffic comes in that particular VLAN with the destination MAC is not known to the switch, it will forward it to a specific port which is specified rather than flooding it. 

     

    Thanks 

    Arul



  • 5.  RE: show ethernet-switching statistics on EX4200

    Posted 06-21-2017 04:22

    But how it can help me with my problem? I need to learn what level of flooding is there, and maybe find what MAC addresses are involved.

     

    Regards,

    Pawel



  • 6.  RE: show ethernet-switching statistics on EX4200

    Posted 06-21-2017 04:42

    The show ethernet-switching table command shows that an unknown unicast packet is received on interface. 

     

    Check the link which i pasted before. 

     

    Thanks

    Arul



  • 7.  RE: show ethernet-switching statistics on EX4200

    Posted 06-21-2017 04:49

    Then as I said before - if i set a port for unknown-unicast-forwarding it will stop flooding unknown unicast to other ports - possibly braking comunication.

     

    Regards,

    Pawel



  • 8.  RE: show ethernet-switching statistics on EX4200

    Posted 06-21-2017 20:54

    try this:

    >show interfaces <name> extensive | match packets

     

    You can specify an interface name of leave it off. This should show you multicast, unicast and broadcast

    Now that will not tell you if it is excessive, since excesive would be dependent on the particular network. You would need some other network monitoring device to check traffic types over a period of time and at different time intervals to see the levels. It would also of coure depends on if the particular environment is using applications that generate these types of traffic.



  • 9.  RE: show ethernet-switching statistics on EX4200
    Best Answer

    Posted 06-26-2017 01:05

    It would still show only total of unicast  packet (both unknow - flooded and "known" -  forwarded), while I am looking only for flooded (unknown). 

    It seems that there is no way to check it on EX 4200. Thanks all!

     

    Regards,

    Pawel