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Cisco IP Phones on Juniper EX4200's

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  • 1.  Cisco IP Phones on Juniper EX4200's

    Posted 03-19-2013 12:35

    Has anyone ever configured/supported Cisco IP phones on Juniper EX-series switches? Can it be done? What are the drawbacks/concerns? I am no Cisco VoIP guru, but I know that they are supposed to use CDP to communicate between phone and switch. Obviously since this is a Cisco proprietary protocol, can it still be supported w/o CDP?


    We are in the equipment selection phase of a project coming down the line and the customer wants to use Cisco VoIP (as well as Cisco WLC and WAP's). There will potentially be a mix however of that along with Avaya phones and MS Lync soft phone.


    I personally am designing for an ALL Juniper EX setup (6x 4200's in a VC x 3 Floors, each with 20G LAGs) aggregating back to a 2-member 4550 VC. The 4550 may/may not have routing enabled, I have not decided yet if I want to use my existing 4200 VC cores for Layer 3 with VRRP between the chassis' (probably overkill).


    I will be spec'ing out Cisco gear as well (since I have to). Any help on the VoIP support on Juniper would be much appreciated !!!!


    Thanks In Advance.


  • 2.  RE: Cisco IP Phones on Juniper EX4200's
    Best Answer

    Posted 03-19-2013 21:48


    Hi Marc,


    As Juniper EX-Series does not support CDP, so it can be acheived through lldp-med.

    These are the Cisco ip phones which fully support the LLDP-MED protocol.


    The following Cisco phones models with firmware version 8.3(3) or later support the LLDP-MED protocol:

    •7970G/ 7971G-GE
    •7975G "


    See this link





    Also these might be usefull data. I suggest you go through these doc before deployment.






  • 3.  RE: Cisco IP Phones on Juniper EX4200's

    Posted 03-20-2013 11:26

    turn on both LLD and LLDP-MED and all should work.

  • 4.  RE: Cisco IP Phones on Juniper EX4200's

    Posted 03-20-2013 11:56

    @dipanc -- Thank you for that information. I read through all the material and from what it sounds like, I can support Cisco IP Phones on EX switches. Whether or Not the Cisco phones support LLDP-MED, they should still work with some added caveats.


    Unfortunately, 2 of the 3 phones that were selected do not support LLDP-MED. That means that I will have to hard set the Voice and Data vlans into every phone manually, as well as the 802.1P parameters. Having the LLDP-MED support would make our life a lot easier from a management perspective. Having to hardcode those parameters removes the portability of the user taking their phone from one floor to another (unless of course those VLAN's live on that floor).

  • 5.  RE: Cisco IP Phones on Juniper EX4200's

    Posted 03-21-2013 00:01

    That should work....All the best with the deployment...

  • 6.  RE: Cisco IP Phones on Juniper EX4200's

    Posted 04-20-2018 08:16