VLAN Question

When there are multiple VLANS on a LAN along with non VLAN traffic (native VLAN 1) do I need two FA ports on the router to ensure Inter-VLAN Routing and one to pass the VLAN 1 traffic? Or, is there a way to add the non VLAN traffic on the sub-interface of the trunked link between the router and switch.

Find more posts tagged with

Save $250 on 2025 certification boot camps from Infosec!

Book now with code EOY2025

Button

Comments

networker050184

You can use the encapsulation dot1q 1 native command.

billscott92787

With inter-VLAN routing you can use the traditional method or the router-on-a-stick method. The traditional method is where there is one interface PER VLAN. Router-on-a-stick, you can use to be able to communicate for each individual VLAN. Even VLAN 1 is a VLAN so you are dealing with VLAN traffic. You would configure create logical subinterfaces of that one interfaces, one sub interface for each VLAN. This will allow traffic management for multiple VLANs. For example you could have the following:

int fa0/0.1
encapsulation dot1q 1
ip address 192.168.1.1 255.255.255.0

int fa0/0.2
encapsulation dot1q 2
ip address 192.168.2.1 255.255.255.0

int fa0/0.3
encapsulation dot1q 3
ip address 192.168.3.1 255.255.255.0

and so on.

wastedtime

I am assuming you are talking about 802.1q. The native traffic is untagged and anything else that is untagged is considered in the native vlan. Just because it isn't tagged doesn't mean that it isn't part of a vlan. So you would just need one port.

telecomops101

I understand how to enter the commands for the non-native vlans, so would I just need to enter the below command to pass my native vlan 1 traffic and only have to use one FA port?

Interface fa0/0.1
encapsulation dot1q native 1
ip address 192.168.1. 255.255.255.0

networker050184

telecomops101 wrote: »

I understand how to enter the commands for the non-native vlans, so would I just need to enter the below command to pass my native vlan 1 traffic and only have to use one FA port?

Interface fa0/0.1
encapsulation dot1q native 1
ip address 192.168.1. 255.255.255.0

Yep thats it. And the same for any other VLAN you make the native.

Its encaps dot1q 1 native not the other way around though and of course a complete ip address.