A lot has been written about where VTP client, server and trasparent modes store the VLAN configuration
I am also sure that for a lot of people this is still unclear because of the huge amount of resources that contradict each other
Via this posting I hope someone with recent gear and recent IOS can do some testing (for the sake of simplicity let's not talk about CattOS)
I like to believe that Cisco Exames are based on recent IOS version (at least for CCNA)
I'm also under the impression that this behaviour differs between older and newer IOS versions
Setup should be two switches in an isolated environment, trunked together
Please let us know which switch models you used and which IOS version
I think the following steps should clarify a lot. Of course this is a discussion group so we are all open for discussion and improvements in the setup.
Create one VTP domain for Switch A and Switch B
Configure Switch A as VTP server. Configure Switch B as VTP client
Add VLAN TEST on Switch A
Is there a vlan.dat file on Switch A and Switch B ?
Where is the vlan.dat file located ? Is it visible using the show flash command ?
Is the VLAN TEST visible on both switches ?
This might point out that vlan.dat is stored on flash (where ios is stored) and not on nvram (where startup config is stored)
Disconnect Switch B from Switch A and issue a reload on Switch B (which is the VTP client switch)(without a copy run start)
Is the vlan.dat file still present on Switch B ?
Is the VLAN TEST still visible when using a show vlan brief command ?
This might point out that VTP client mode does not get the complete vlan informatoin database from the VTP server each time it reloads. Instead it would only get updated vlan information from other VTP client or servers (if their revision number is higher)
On Switch B issue the write erase command and also the delete vlan.dat command
Issue a reload command on switch B
After reload change the VTP mode on switch B to transparent (because of the delete and erase it should have defaulted to server mode)
Create VLAN TRANSPARENT on Switch B
Issue the copy run start command on Switch B
Reattach Switch B to Switch A
Is there a vlan.dat file on Switch B and if so, where is it located ?
According to the Wendell Odom books for CCNA, transparent switches store vlan configuration both in Flash and in running-config
Can you see vlan configuration when you issue show running config ?
Create VLAN TRANSPARENT_TWO on Switch B
Issue a reload command on Switch B (without copying the running config the )
Is there a VLAN TRANSPARENT on Switch B ?
Is there a VLAN TRNASPARENT_TWO on Switch B ?
If only VLAN_TRANSPARENT is present this would mean that the vlans are not automically saved to vlan.dat on VTP transparent mode switches and that copy run start is needed
Thanks in advance for cooperation