Switching

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Remote Port Mirroring

  • 1.  Remote Port Mirroring

    Posted 11-24-2020 17:35
    Hi,

    I need to capture traffic for a device on Switch-A. Currently, Switch-A connects to Switch-B, which connects to Switch-C.
    My monitoring server is connected to Switch-C.

    The links between these switches are trunk links (aggregated in some cases), with production VLANs on them.

    My question is, if I want to add a 'remote-capture' VLAN to each switch, do I have to (or should I) have a separate trunk link to my production traffic?
    I understand the risk of putting a load on the link, but we're talking about very small amounts of traffic here.


    Thanks for your advice


  • 2.  RE: Remote Port Mirroring

     
    Posted 11-24-2020 18:04
    hi Luke,

    You can use the same trunk for the "remote-capture Vlan".  This should be a dummy VLAN only for the purpose of the port mirroring and should only be configured on the devices and interfaces involved on the capture. 

     So, as there should not be intervlan traffic between this VLAN and existing ones, there should not be impact. Example config:
    https://www.juniper.net/documentation/en_US/junos/topics/example/port-mirroring-remote-ex-series-els.html

    Note: if using multi instance xSTP versions like VSTP or MSTP make sure the new VLAN is properly allowed. if using RSTP it should follow the existing path.

    Please mark as solved if it clears your concerns.