How to configure VLANs on Cisco Catalyst Switch

This topic is to discuss the following lesson:


thanks! easy to understand well explained


Very neatly explained. Thanks.

Hi Rene, I installed cisco packet tracer and execute vlan lab and everything looks good so far. What is GNS3vault and is it downloadable for free?


Hi Maruti,

GNS3 is a free Cisco emulator for routers. is my other website, that’s where I offer free labs that you can load in GNS3.


Got it Rene!


Thanks so much Rene.

thanks…very easy to understand =)

Dear René,

Good job as usual !

What is the difference between Admininstrative Mode and Operational Mode in the output of the " show interfaces fa0/2 switchport " ?

What if the output is not the same (I mean in this case " static access ") ?

Thks in advance,


Hi Prince,

This is because of DTP (Dynamic Trunking Protocol). It’s a protocol that you can use between switches to negotiate if the interface should be in access or trunk mode. Take a look here, it explains everything:

DTP (Dynamic Trunking Protocol)


Great René, you are The Man ! :slight_smile:



Hi Rene,

When i type “vlan database” on a Cisco 2851, it show me this message:

Router#vlan database
% Warning: It is recommended to configure VLAN from config mode,
as VLAN database mode is being deprecated. Please consult user
documentation for configuring VTP/VLAN in config mode.

How i can configure it from config mode?. I have to use VTP or otherwise?

Thanks to you





Hi Diego,

The “vlan database” command is an old CatOS command. We don’t use it anymore.

Old CatOS method:

vlan database
vlan 10

New IOS method:

conf t
vlan 10

Hope this helps.


Hello Rene,

What would happen if we delete VLAN that exit on switchport?
a) port down and use native vlan
b) port down and use default vlan
c) port up and use native vlan
d) port up and use default vlan


Thank you

Hi Sinan,

By default the native and default VLAN is both VLAN 1 which you can’t delete. If your switchport is assigned to any VLAN which you delete then it will just “float” around in no man’s land…it won’t be assigned automatically to another VLAN.


when i use switch 2950 enter all the config info all of my links are still show up as if all my interfaces 0/1 & 0/2 are down but all my links are up what do you think the issue could be.

when i config the switch 2950 fa1 and fa2 with vlan 50 conn my pc 1 to fa1 conn pc to fa2 the computer are unable to ping each other

i followed these steps

SwitchA(config)interface fa0/1
SwitchA(config-if)#switchport mode access
SwitchA(config-if)#switchport access vlan 50
SwitchA(config)interface fa0/2
SwitchA(config-if)#switchport mode access
SwitchA(config-if)#switchport access vlan 50