NerissaHolloman517

CCNA and CCNP candidates who have their own Cisco residence labs often e-mail me about an odd predicament that happens when they erase a switch's configuration. Their startup configuration is gone, as they anticipate, but the VLAN and VTP data is nonetheless there!

Sounds unusual, doesn't it? Let's look at an instance. On SW1, we run display vlan brief and see in this abbreviated output that there are 3 further vlans in use:

SW1#show vlan br

10 VLAN0010 active

20 VLAN0020 active

30 VLAN0030 active

We want to entirely erase the router's startup configuration, so we use the compose erase command, confirm it, and reload with out saving the operating config:

SW1#publish erase

Erasing the nvram filesystem will get rid of all configuration files! Continue?

[confirm]

[OK]

Erase of nvram: complete

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

SW1#reload

Technique 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 again. And even though the startup configuration was erased, the vlans are nevertheless there!

Switch#display vlan br

ten VLAN0010 active

20 VLAN0020 active

30 VLAN0030 active

The cause is that this vlan and VTP info 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 tiny trick to deleting this file. The switch will prompt you twice to ask if you genuinely want to get rid of this file. Don't 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 actual Cisco equipment, and by performing lab tasks over and over. Repetition is the mother of ability, and by definitely erasing your VLAN and VTP information by deleting the vlan.dat file from Flash, you'll be constructing your Cisco expertise to the point where your CCNA and CCNP exam good results is a certainty. inside motorcycle superstore