Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Vlan in Vlan segmentation is it possible ?

Hello guys ,

I have a L3 switch , using it for carrier switch of physical wan connections and a Cisco 3825 my wan router. So i have twi Gigabit interfaces on the router. On one of them there are two sub-if with secondary address and tagged in one vlan going to the carrier switch. Now the problem is i want to isolate the traffic between two physical connections wich are flowing in that vlan. There are in one broadcast domain and i , have lack of interfaces on the router. Is therem probably some Vlan in Vlan encapsulatio ? Any ideas are welcome

Thanks in advance


Re: Vlan in Vlan segmentation is it possible ?

I havenot really understood your question and your requirement. Which switch is this ?

You can look for configuring Private vlans and protected port on the switch.Please find the link below with some information on this:


-amit singh

New Member

Re: Vlan in Vlan segmentation is it possible ?

Hi again

So the switch is used for the connections from the ISP. There is then link from the switch to the WAN router Cisco 3825. From the router to switch link there is vlan flowing with id for instance 45. On the switch there is vlan 45 with two ports 3 ports in this vlan. The idea is that from the router sub-if with two addresses traffic flow to switch and then on the switch take it's route on the separate physical connections to the ISP's. Therefore in the switch there are in one broadcast domain because of the vlan. I want to segment them , so one ISP don't see the traffic from the other connection.

CreatePlease login to create content