I'm studying for my CCENT and I have a question on the following setup as I'm not sure how it works to be honest. The following is setup in production.
Cisco Switch 2960
Cisco Router 1841
On the switch vlan 1 is shutdown which from my understanding is the default vlan aka Native vlan.
we have two other active vlans 100 data and 200 voice we use VOIP with Mitel phones.
The router has one Native vlan which is fa0/0 this interface is subbed out to fa0/.100 and fa0/.200.
Each subinterface on the router has 802.1q with the correct vlan enabled.
I know from the switch documentation a trunk port configured with 802.1q can receive tagged and untagged traffic and by default the switch forwards untagged traffice in the native vlan configured for the port and the native vlan is 1 by default.
Here is the crux of me not understanding: quick side note the pc's sit behind the phone.
if vlan 1 has been disabled on the switch and a pc that sits on vlan 100 and that doesn't support 802.1q. Sends a packet out the trunk port, the trunk say's ok this is untagged so it must be using the native vlan and sends it to the router. The router get's this packet know's it's not tagged and say's it must be a member of the native vlan which is aslo 1. Since the packet comes in untagged and the router has 2 vlans that sit technically witin vlan 1 since it's subbed interfaced out it by default goes to 100? Because if a phone sent the packet it would be tagged with 200 and the trunk knows to send it to .200 interface.
I'm not sure if this reads the best but if you have any thoughts I would like to hear them.
It does depend on how the port is configured on the switch but if you have a "switchport access vlan 100" then yes the switch then knows the data traffic is meant to be in vlan 100.
You can have a PC NIC be in more than one vlan but the NIC needs to support tagging ie. the port would be configured as a trunk on the switch.