Solved: computer ip address for router on a stick

John Cheetley · ‎03-29-2018

Hi Cisco techs,

Please let me know if posted in wrong section

How does a computer connected to a Cisco ip phone (via 10/100 port) in a data vlan gets its ip address for router on a stick scenario and how does the router "know" who to send the packets too. I presume this is something to do with the vlan and either tagged or untagged?

chrihussey · ‎03-29-2018

Generally, the switch port the phone connects to has a data and voice VLAN assigned. The phone has an internal switch and packets from the PC are not tagged and end up in the data VLAN. The VoIP packets are tagged with the voice VLAN. This provides the separation.

Assuming we are talking DHCP, the computer would get an IP address, mask and gateway just as it would if there wasn't a phone in the middle.

Hope that helps

View solution in original post

chrihussey · ‎03-29-2018

Generally, the switch port the phone connects to has a data and voice VLAN assigned. The phone has an internal switch and packets from the PC are not tagged and end up in the data VLAN. The VoIP packets are tagged with the voice VLAN. This provides the separation.

Assuming we are talking DHCP, the computer would get an IP address, mask and gateway just as it would if there wasn't a phone in the middle.

Hope that helps