vlan configuration

Have a question or want to start a discussion? Post it! No Registration Necessary.  Now with pictures!

Threaded View
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?


1> PC(vlan3)----Phone(vlan2)----SW
2> Phone(vlan2)----SW----PC(vlan3)
          |____________|(vlan3)



Re: vlan configuration
Quoted text here. Click to load it

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"?

Good luck,

Mike
------
Cisco IP Phone Headset Adapters
www.ciscoheadsetadapter.com



Re: vlan configuration
:s6Cdnb2xGaTxcSDYnZ2dnUVZ_qarnZ2d@comcast.com...
Quoted text here. Click to load it
of
There
their

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?




Re: vlan configuration
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?

Good luck,

Mike
------
Cisco IP Phone Headset Adapters
www.ciscoheadsetadapter.com


Quoted text here. Click to load it



Re: vlan configuration
:pdOdnXcc8-AOHyPYnZ2dnUVZ_uiknZ2d@comcast.com...
Quoted text here. Click to load it
should
back
need
port
the
trunk" -
Quoted text here. Click to load it
configure
communication.
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.




Site Timeline