Office 250/5300-series phones on Cisco C3850

[SCPanther]

First time caller, here...

I'm working with a vendor to get this up and running, and I'm trying to get the voice vlan configured correctly on my switches, the core being C3850 and the edges C2960X. I've read quite a few docs, some with conflicting information, but here's where it stands:

My data Vlan is the default, and the devices on it are in 10.10.0.0/16.
I've defined Vlan 50 as the voice vlan. The phones and Office 250 have static IP addresses, not using DHCP, and are in 10.50.0.0/16. The phones currently connect with the server and can dial each other. When the phones are booted, however, they show VLAN=None, and they can't be pinged, nor can the Office 250 (henceforth known as "the server").

interface GigabitEthernet2/0/37
 switchport mode access
 switchport voice vlan 50
 no cdp enable
 spanning-tree portfast
 service-policy input AutoQos-4.0-Trust-Cos-Input-Policy
 service-policy output AutoQos-4.0-Output-Policy

(Even though I typed the command switchport access vlan 1 it doesn't seem to show, presumably because it is the default vlan.)

I included the "no cdp enabled" command on the recommendation of a Mitel technical document. What's interesting is that if I don't include that command, leaving cdp enabled, the phone will show VLAN=50 when it boots, and will respond to pings at its 10.50.. address.

But, when that's the case, it can no longer contact the server, even if I've used the same setting on the port the server is connected to. The server also can't be pinged under either scenario.

I will add, I haven't tried cycling the power on the server. I just unplug and replug the network cable after I've made changes to its port config.

Can anyone offer some insight? I've seen a lot of references to setting options on DHCP, but didn't think they would apply if we're manually assigning all of our addresses.

[Tech Electronics]

SCPanther,

So, you are not letting the MiVO-250 handle DHCP for the phones on VLAN 50? What do you want handling DHCP or are you using an IP Helper Address?

Here is the basics of how we setup a Voice VLAN on our networks.

1. The MiVO-250 is on an Untagged Voice VLAN Port. Another way of saying this is that the MiVO-250 is on a port that has its native VLAN set to the Voice VLAN if that makes more sense to you. This is because the MiVO-250 doesn't support VLAN tagging and it needs to be on an Access port for the Voice VLAN and you would then have your L3 device pass traffic between the two. You could set it up as a Trunk Port, but you would then need to define the Native VLAN to be the Voice VLAN for that Trunk Port; make sense? The problem with a Trunk Port is that they typically don't pass DHCP requests reliably or at least they didn't used to back the day when I work on Cisco.

2. The Switch will provide CDP/LLDP-MED to the phones when they request it. The Information required is the VLAN ID, L2P, and DSCP if things need to go to L3 for anything.

When a phone boots up it gets its VLAN ID and L2P from the switch and then it will send out a DHCP request on that VLAN to get a IP Address; in this case from the MiVO-250.

Clear as mud.

Thanks,

TE

[SCPanther]

TE,

Thanks much for the swift reply. I definitely don't have a thorough enough understanding about what I'm doing yet, but your information about the 250 not supporting Voice Vlan tagging seems to be the key info I was missing.

I changed its port to switchport access vlan 50 and then re-enabled cdp on the port to the phone. Now the phone correctly identifies the VLAN on bootup, connects to the server, and both can be pinged!

Regarding your DHCP question, I'm not the one configuring the MiVO-250, but no, my understanding is that we're not using DHCP to configure the phones, but are manually assigning the address on each one.

Thanks again for the assistance!

[Tech Electronics]

SCPanther,

I wouldn't manually set all of your phones with an IP Address unless you just like doing that sort of thing. It would be easier to just setup the DHCP Server in the MiVO-250 to handle DHCP requests for phones on VLAN 50. Since you have it setup as an Access port on VLAN 50 and no other DHCP server on that VLAN then setting it up is really simple. Also, unless you unflag the option to reply to Non-Mitel devices it won't provide DHCP to anything other than a phone.

Thanks,

TE

[SCPanther]

Setting them manually was my vendor's call, but I'll definitely keep DHCP in mind as I dig in and learn more about the system.

[sarond]

If you disabled CDP then you would also need to program a static VLAN into the phone.

So another important thing here is whether you are connecting PC's behind the phones.
If not then you could just switchport access vlan 50 on all the phone switch ports and then you could disable CDP.

When you enable CDP then the switch knows that the phones are a voice device and puts them in the voice vlan, as you are seeing.

[SCPanther]

sarond,

We are piggybacking PC's on most of the phones, and I'm trying to implement Cisco's QoS features, so that's why the voice vlan option was necessary, but that's good information.

Thanks!