ICND2 Question - Native VLAN vs Default VLAN?

Node Man

Hi Everybody,
I may be over-thinking this, but I am also worried that I am misunderstanding something:

Is there a difference between a 'native vlan' and a 'default vlan'?

Thanks for your answers.

DCD

The default VLan is VLan1 and also by default it is the Native VLan as well but here is the tricky part you can change the Native VLan to another VLan with the switchport command which will take it off of VLan 1.

ChickenNuggetz

Node Man wrote: »

Hi Everybody,
I may be over-thinking this, but I am also worried that I am misunderstanding something:

Is there a difference between a 'native vlan' and a 'default vlan'?

Thanks for your answers.

The default vlan is excatly what it sounds like: the default vlan on a switch. If you were to make no vlan changes on a brand new switch, the only vlan there would be is the default vlan (which for Cisco is always vlan1).

The native vlan has to do with vlan tagging. As frames are making their way from a host to a switch to another host, the frames are tagged with a little "flag" that indicates what vlan that frame is a part of. So think about this: what if you have a frame come into a switch that has no little "flag?" This is where a native vlan comes in. Any untagged (no flag) frames are by default sent to the native vlan. The native vlan will be whatever vlan you configure it to be. If you dont configure the native vlan, it is automatically set to be vlan1 by default.

Considering the two definitions above, often times your native vlan and the default vlan are one in the same. Since the default vlan is 1 and the native vlan is by default vlan 1, they are essentially the same thing. However, if you were to configure you native vlan to be, say something like vlan 7, then any untagged traffic would be sent to vlan 7.

Hope that helps!

DCD

ChickenNuggetz wrote: »

The default vlan is excatly what it sounds like: the default vlan on a switch. If you were to make no vlan changes on a brand new switch, the only vlan there would be is the default vlan (which for Cisco is always vlan1).

Not exactly do the show VLan and VTP command.

ChickenNuggetz

DCD wrote: »

Not exactly do the show VLan and VTP command.

Yes, VTP could change the VLAN configuration without physically changing the config on the switch, but we're not talking about VTP. I was trying to keep it as simple as possible to illustrate the differences!

DCD

That not what I was saying. This is the output from a switch with no configuration using the show VTP status command. Check out the highlighted text.

Switch#show vtp status
VTP Version : 2
Configuration Revision : 0
Maximum VLANs supported locally : 255
Number of existing VLANs : 5
VTP Operating Mode : Server
VTP Domain Name :
VTP Pruning Mode : Disabled
VTP V2 Mode : Disabled
VTP Traps Generation : Disabled
MD5 digest : 0x7D 0x5A 0xA6 0x0E 0x9A 0x72 0xA0 0x3A

dpjackal89

the default vlans are vlan 1, 1002-1005. These are the default vlans on all switches in their default state (no changes made).1002-1005 are reserved vlans. So on EVERY single brand new switch you will see 5 vlans when using the show vlan command but in reality the only default vlan is 1. You don't really count vlans 1002-1005 when it comes to what you are asking in my opinion.