GS1900-16 - No IP from upstream DHCP server for voice VLAN device

My landscape consists of a UDM-PRO providing DHCP for two subnets named LAN (VLAN1) and SIP (VLAN10). The configuration on UDM-PRO works fine for any devices directly connected to a UDM-PRO port. In fact, it even works for a phone connected to an unmanaged switch connected to another port of the UDM-PRO.
The only device that doesn't work is connected to a GS1900-16 that is directly connected to a UDM-PRO port. Oddly enough the MAC list properly identified the device as SIP, but it just never gets an IP address from the DHCP server on the UDM-PRO.

On the GS1900-16, port 1 is the uplink port to the UDM-PRO and port 16 is the phone that doesn't get an IP.

Here is my configuration:

VLAN -> Port
Ports 1 to 15 are set to 1, ALL, Disable, Disable
Port 16 is set to 10, ALL, Disable, Disable

VLAN -> VLAN Port
VLAN1
All ports are set to Untagged
VLAN10
Port 16 is set to Tagged

VOICE VLAN -> Port
Port 1 is disabled
All other ports are enabled

I have also created a MED VLAN Policy for VLAN10 and it is enabled & assigned to ports 2 to 16. Port 1 is disabled and policy has been assigned.

Nothing special is going on on the UDM-PRO and the SIP (VLAN10) subnet is giving out IP to other devices just fine.

Thank you for any feedback!

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  • TimThomTimThom Member Posts: 7
    edited October 3, 2020 1:44PM

    MmmKay. . .  here are some things to try -

    If you are using Auto-voice-VLAN for your phones -

    Auto-voice-vlan (as far as I know) won't work correctly
    if the port is set for VLAN10 Tagged.  I think the ports need
    to be set to VLAN10 Excluded.

    Make all ports PVID1, All, Disable, Disable.
    VLAN1, make all UNTAGGED
    VLAN10, make all EXCLUDED   (or at least the ones with phones on them.)

    This way, you can plug either a PC or printer in a port,
    and it will happily live on VLAN1, without knowing any better.
    Or, you can plug in an IP phone, and, assuming the MAC has been set
    in the OUI, and Auto-voice-vlan is configured, it should immediately flip
    the phone onto VLAN10, so it can wait for DHCP from the router.

    You can also prevent certain ports from accessing VLAN10,
    by setting it to VLAN10 Forbidden.

    Double-check the VoiceVLAN section, to make sure
    that you have VoiceVLAN ID set and enabled,
    that you have your ports (in the VoiceVLAN section)
    set to Enable, and of course that you have your OUI set
    for your IP phones.

    The port going back to your router should be set up as
    VLAN1 Untagged, all other VLANS Tagged.
    (I am not sure if it matters if it is defined as a Trunk port or not.
    My network at the office works fine without it defined as a Trunk port.
    But, you can poke around with it to see if it has any impact.)



  • JSTJST Member Posts: 6
    edited October 6, 2020 2:38AM
    Hi @TimThom and @Zyxel_Derrick

    Thank you for getting back to me!

    I finally got it working. Here is what worked for me in the end.

    VLAN -> Port
    Ports 1 to 16 are set to 1, ALL, Disable, Disable

    VLAN -> VLAN Port
    VLAN1
    All ports are set to Untagged
    VLAN10
    Port 1 and 16 are set to Tagged
    All other ports are set to Untagged

    VOICE VLAN -> Port
    Port 1 is disabled
    All other ports are enabled

    MED VLAN Policy for VLAN10
    Enabled & assigned to ports 2 to 16
    Disabled and no policy for Port 1

    It seems that it really required the VLAN 10 port 1 tag to work. So, both of your posts helped me with finding a solution! :)

    To be on the safe side, I have also added DHCP option 132 to my setup. It is pointing my Yealink phones to VLAN 10 now. That said, the configuration above works without DHCP option 132 being set.

    Thank you to both of you!!!
  • JSTJST Member Posts: 6
    Bad news! My solution has stopped working when I had to put another switch in front of the switch with the phone.
    Here is my new setup:
    UDM-PRO (DHCP) -> GS1900-16 -> GS1900-8
    The MAC tables on both GS1900 properly show the connected phone, but it just doesn't get an IP address.
    I am guessing that I need some extra configuration to properly pass the request upstream through the upstream switch.
    Any ideas?
  • Zyxel_DerrickZyxel_Derrick Zyxel Official Agent Posts: 76  mod
    Hi @JST

    Did you configure the member of VLAN10 to the ports that connected between GS1900-16 and GS1900-8?
    Also, did you configure PVID to the port that connected to IP phone?
    Thanks

    Best regards,
    Zyxel_Derrick
  • JSTJST Member Posts: 6
    @Zyxel_DerrickThank you for getting back to me!

    What do I need to do to configure the member of VLAN10 on the ports of both switches?
    I have setup the PVID, but that's not enough.

  • JSTJST Member Posts: 6
    edited October 21, 2020 4:41AM
    I got it to work. I basically tagged VLAN10 on all ports on the GS1900-16.

    @Zyxel_Derrick Is that what you had in mind?
  • JSTJST Member Posts: 6
    Yes, it is. Thank you for pointing out the solution to me!!  :)
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