Hi all,
I've just been testing using Cisco IP Phones with the Linksys SRW224P switch (which do not support CDP and automatic voice VLAN assignment). It's all pretty straightforward, however, I found I needed to enable the "PC Voice VLAN Access" setting for the IP phone to get the PC (attached to the phone) communicating on the network. With this setting disabled, the PC cannot communicate on the network, even if the correct data VLAN ID is configured in the "PC VLAN" setting on the phone. This same issue is also replicated if I disable CDP on a Cisco switch and manually configure the voice VLAN ID on the phone.
Any ideas as to why this is the case? My understanding of the PC Voice VLAN Access setting is that it enables an attached PC to access the voice VLAN (i.e. tag frames with the voice VLAN ID and send on the voice VLAN, and receive frames on the voice VLAN). The traditional port mirroring issues associated with this setting aren't an issue nowadays, as you now have the additional "Span to PC Port" setting to control this.
