MirelleEddy911

CCNA and CCNP candidates who have their personal Cisco residence labs frequently email me about an odd circumstance that happens when they erase a switch's configuration. Their startup configuration is gone, as they expect, but the VLAN and VTP info is nevertheless there!

Sounds strange, does not it? Let's appear at an instance. On SW1, we run show vlan short and see in this abbreviated output that there are three extra vlans in use:

SW1#show vlan br

ten VLAN0010 active

20 VLAN0020 active

30 VLAN0030 active

We want to completely erase the router's startup configuration, so we use the write erase command, confirm it, and reload without having saving the running config:

SW1#compose erase

Erasing the nvram filesystem will remove all configuration files! Continue?

[confirm]

[OK]

Erase of nvram: total

00:06:00: %SYS-7-NV_BLOCK_INIT: Initalized the geometry of nvram

SW1#reload

System configuration has been modified. Save? [yes/no]: n

Proceed with reload? [confirm]

The router reloads, and immediately after exiting setup mode, we run display vlan brief yet again. And even although the startup configuration was erased, the vlans are nonetheless there!

Switch#show vlan br

ten VLAN0010 active

20 VLAN0020 active

30 VLAN0030 active

The purpose is that this vlan and VTP details is really kept in the VLAN.DAT file in Flash memory, and the contents of Flash are kept on a reload. The file has to be deleted manually.

There is a small trick to deleting this file. The switch will prompt you twice to ask if you really want to get rid of this file. Do not sort "y" or "yes" just accept the defaults by hitting the return crucial. If you variety "y", the router attempts to delete a file named "y", as shown here:

Switch#delete vlan.dat

Delete filename [vlan.dat]? y

Delete flash:y? [confirm]

%Error deleting flash:y (No such file or directory)

Switch#delete vlan.dat

Delete filename [vlan.dat]?

Delete flash:vlan.dat? [confirm]

Switch#

The very best way to prepare for CCNA and CCNP exam accomplishment is by operating on genuine Cisco gear, and by performing lab tasks more than and over. Repetition is the mother of skill, and by really erasing your VLAN and VTP info by deleting the vlan.dat file from Flash, you are going to be constructing your Cisco abilities to the point exactly where your CCNA and CCNP exam accomplishment is a certainty. trailers for sale discussion