4 Replies Latest reply on Jan 16, 2015 7:14 AM by markfreeman

    DHCP issues on Netvanta 7100

    cahollow New Member

      Good morning!  I have a Netvanta 7100 that is not yet in production.  I'm in the process of prepping it to both replace their edge router and their existing phone system.


      The 7100 ONLY has a voice vlan DHCP pool as there is an existing DC which is running DHCP for the data vlan. The 7100 is currently only plugged into my workstation, NOT on the same network as the DC running DHCP, and a Polycom/Adtran VVX 410 phone..


      The issue that I'm having is that the phone can't get an IP address.  I turned on debugging and was able to see that the phone was trying to get a DHCP lease for the data network (native vlan on the port to which it is connected) and will only request a voice vlan IP if I manually set the VLAN on the phone or set the port on the 7100 to be access for the voice vlan rather than a trunk port.


      My question is, is there a way around this?  Having to configure all the ports as access just to get the phones IPed and registered the first time and then changing them back is kind of a pain.  I'm willing to do it if thats the only way, but I was hoping there was a way around this.  I guess I'm spoiled coming from the Cisco world where CDP is used to determine what vlan phones should be on and all of this is negotiated behind the scenes!

        • Re: DHCP issues on Netvanta 7100
          spantula Employee

          If I understand your configuration correctly: on 7100 there a DHCP running for VLAN which is meant for VOIP devices and the port configuration is trunk with native vlan as the DATA vlan for which DHCP server is in DC, and voice vlan is configured for the port.

          If the LLDP is enabled on the phone and the switch, then it would definitely learn the voice vlan from the LLDP and try on the network.


          Would suggest for couple of checks

          1. LLDP is enabled on the phone : Administration setting >Network Configuration>Ethernet Menu> VLAN >LLDP

          2. Switch port as LLDP enabled.

          And even if the switch is sending lldp pkts, phone is not getting voice vlan from the LLDP, then should be a problem with phone s/w. Would recommend to pick the new s/w for the phone.

          • Re: DHCP issues on Netvanta 7100
            markfreeman Employee


            All the switch ports in the 7100 are set to trunking with the native VLAN set to 1. WHen you plug in a new phone it does not know its voice vlan yet and so it sends an untagged eth frame which then when the 7100 gets it will tag it with the native vlan 1, since you don't have DHCP on vlan 1, the phone can't get an IP.



            Log into the gui of the 7100 and go to DATA > Switch > Ports and for the port that your phone is plugged into, change the membership from Trunk To VLAN 2. Click Apply on that page to save your settings. Reboot the phone. The phone should then come up on VLAN 2.


            Let us know if that worked.


            Once you put the 7100 in production you can change *** back to trunk or if all your phones are going to be directly plugged into the 7100 and not your network, then you can just set all them to vlan 2 and keep it that way. There are different ways of accomplishing this.


            We go over how to do this type of set up in our ATSP/UCAS certification class which teaches the admins how to install and configure the 7100.

            More info here:

            ATSP/UCAS - VILT

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