Solved: Router > Switch > Router Setup

Mokhalil82 · ‎05-05-2015

Hi

Just have a few basic questions that I am unsure of, although I can get connectivity to work, I am just trying to understand how it works.

So I have labbed a "router1 > switch > router2 setup. So questions I have are:

1) When router 1 sends to router 2, it sends on the native vlan, when I change the native vlan on the switch, am I right in saying it then sends over this new native vlan, despite config is only on the switch

2) Can I use both a subnet on the physical interfaces for the routers to communicate to each other on, then a separate subnet on sub-interfaces for the routers to communicate with the switch and vlans on different subnets. Is the router using the native vlan to communicate and subinterfaces tagging the packets.

3) If I choose to only use subinterfaces, does one of the sub interface have to be part of the native vlan, so the router subnet being the native

Thanks

Bilal Nawaz · ‎05-05-2015

1) you havent told us the pre set up on router side. Untagged or tagged? If R1 had sub-if untagged/native vlan 1 and switch had untagged vlan 5, R2 having untagged vlan 1, you would still have connectivity from R1 to R2.

2) No, when you create sub interfaces you cannot have ip address on the main physical interface. You will instead have to create multiple sub interfaces. One sub-if can use native vlan. Other can be tagged.

3) if you create sub-if's, there is not a specific need to have one sub interface to be native vlan, all of them can be tagged.

Hope this helps.

Bilal

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Bilal Nawaz · ‎05-05-2015