Assistance with DHCP Relay and Auto Voice VLAN

[bcanderson]

Hello, I'm hoping someone is able to offer any assistance for the following scenario, any help would be appreciated.

The network is a SMB consisting of an SG300 with multiple SG200s at the edge, about 150 PCs and 100 VoIP phones (phones are in testing). There are two VLANs, the original VLAN 10 (10.1.x.x) for data and a new VLAN 5 (10.100.x.x) for voice.

The VLANs are functioning properly and are routed and can communicate with each other. There is a Win2008 DHCP server on VLAN 10 that operates normally for the data VLAN but will not assign the correct addresses to the voice VLAN automatically (the phones currently get an address from 10.1.x.x). DHCP Relay is setup on the SG300 pointing to the DHCP server. The Auto Voice VLAN is setup on the SG200s and correctly shows the port coming up as 5T, 10UP when a phone is plugged in. If I hardcode the phone to VLAN 5 in the phone config, it will receive the correct VLAN 5 address, otherwise the phone boots and gets and address from VLAN 10. Please let me know if I am missing something or if all phones need to have that manually entered - I was assuming the Auto Voice VLAN would do that automatically.

Thanks,

Brian

[Tom Watts]

Hi Brian, what kind of phone are you using? Additionally, does the phone support tag VLAN? It sounds like the phone may be expecting an untag packet if they are not designed to have a computer connecting through the phone as the set up suggests.

-Tom
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[bcanderson]

  Hi Tom, thanks for the reply. I have been testing with various Polycom phones (SP 335, VVX310) and all do the same thing - the PC connected to the phone will come up fine on VLAN 10, but the phone comes up on VLAN 10 unless we go into the phone config manually and set VLAN 5 (default is empty on the phone). The switch shows the port as correctly chaning to 5T 10U (without a phone plugged in it shows 10U). We were trying to avoid any manual config on the phones - but I cannot see why this isn't working. Is this a typical setup?               

[Tom Watts]

Hi Brian, this may be a problem with LLDP.

You may want to look in to making a LLDP policy.

https://supportforums.cisco.com/docs/DOC-27005

-Tom
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