I have our network such that the phones are on tagged VLAN 90 (assigned via lldp-med from the switch), while the Epygi LAN is on port that is untagged on VLAN 90. This means that Epygi can do DHCP for phones, while the corporate DHCP server can do DHCP for other devices as required, and we can utilise the pass through port on the phones to plug PC's into the phones.

This almost works perfectly - from factory settings the phones boot up on VLAN 10 (untagged VLAN), the switch broadcasts that phones should be on VLAN 90, and the phone reboots onto VLAN 90. This all falls to pieces though when the Epygi provisions the phone and tells it that it should be on the untagged VLAN, and also not to listen to the switch about VLAN assignment anymore, and the phone reboots and is back on untagged VLAN 10.

The help shows an option "Enable VLAN Tagging - is used to enable/disable setting the VLAN ID and priority for IP phones. TIP: The provided IP address will always be from VLAN network. This option is enabled by default.". This appears to be exactly what I want, except that options is not shown on the IP Line Settings config page. All the other options documented in the help are there but this one is not.

When I download the "Legible Configuration" I see the "linesettings.linesettings.(page_id:2).vlantagging enable" option, set to "ON". When I set it to blank and upload it, Epygi says that the upload is successful but the option remains enabled. If I do the same procedure with the pnp_status option it turns off as expected.

The device is a QX20 running firmware 6.2.35/Release.

What am I missing?

My fallback position is to turn off DHCP (and therefore provisioning) on the Epygi and configure the phones manually, but that doesn't sound like fun.