VLAN CONFIGURATION

[sttn]

Does anyone know how to configure a Cisco router 3600 in order to create connection between 2 VLANs?

Many thanks in advance.

[donewald]

Most commonly sub-interfaces are used on a FastEthernet or GIG interface on the router into a trunked interface on your switch (some times called a "router on a stick").

So something like this. Say your switch has an interface (1/1) setup as an 802.1q trunk. This is connected to FastEthernet 1/1 on your 3600. The VLANs are 10 and 20 that you would like to provide routing for on the 3600. The configuration on the interface would look something like this.

config t

interface FastEthernet 1/1.1

encap dot1q 10

ip add 1.1.1.1 255.255.255.0

interface FastEthernet 1/1.2

encap dot1q 20

ip add 2.2.2.2 255.255.255.0

Hope that helps you,

Don

[milan.kulik]

It is also necessary to define a native VLAN on the router interface if you are using 802.1q trunking.

So check which VLAN is native on your switch trunk port which is connected to the router (VLAN1 is default) and add the native option to your router config.

Example: let's say that VLAN10 is native, your config should contain:

interface FastEthernet 1/1.1

encap dot1q 10 native

Some older IOSes don't support native option, there are some tricks how to handle it:

Regards,

Milan

[sttn]

Milan,

Thanks a lot.

I'll keep that in mind through my test.

Rgds,

Sttn

[sttn]

Don,

Thanks a lot. I'll give it a try.

Rgds,

Sttn