For the following configurations, is there any difference besides the configuration 1 needs trunking for the switch port? In configuration 2, the PC port of the VOIP phone connects to the port of the switch configured as vlan3. Any DHCP issue, like how the PC obtains an IP?
Would you explain, what you mean under "configuration 2"?
Scenario 1 is simple and logical - you have an IP phone, connected to the switch, and PC is connected to the phone. Phone has it's own "phone VLAN", and "PC port" on the phone configured with another VLAN. Basically, if you have Cisco switch and Cisco IP Phone, you don't need to "create trunk" - Cisco has an automatic way to do this. On the switch port you configure "access VLAN, which will be used to mark either PC traffic if no phone connected, or for device, connected behind the phone. Also you configure "auxiliary VLAN" on the port, which will be used for phone communication. DHCP settings will be configured on individual L3 interfaces (vlan2 and vlan3 interfaces).
Scenario 2 is unclear. Ok, you have a phone, connected to the port with VLAN2. You have PC, connected to ANOTHER port, configured with VLAN3. There is no problem with this - devices are in different VLANs and will get their own DHCP IP addresses. But why do you have a link between a phone and switch, marked "vlan3"?
Thank you very much for your reply. It is very detail. In scenario 2, I connect the PC port of the IP phone to the switch where it is vlan 3. The PC attached to the IP phone is connected through the switch. I need this configuration for some testing purpose. Is it possible to configure this way? Any DHCP issue, like how the IP is obtained for both the PC port of the phone and the PC?
If you will connect PC port on the Cisco IP Phone back to switch, it will create loop in your network, and port will be shut down (at least it should be). If you need to connect more than one PC behind the phone, you may connect a small hub or switch into the PC port. But connecting PC port back to the switch from which phone connects is really bad idea. Why do you need it in the first place?
Hi Mike, Thanks for you reply. Can I simplify the problem by imagining the phone as the switch? Then, two switches connect together. The STP will block one of the switchport. If this statement, it would be easier for me to understand.
In the first place, I need to simulate a networking testing plan. I have a few IP phones of different models and a PC. I need to test the scenario of having a PC connected to the PC port of the IP phone. I am not going to connect them physically. Instead, I would like to connect the PC to the switch, and control the PC-Phone connection by turning on and off the switchport. Therefore, I am thinking of connecting the PC port of the phone to one port of the switch and the PC to the other port.