Switch VTP mode change to transparent from client after reload

[mahesh18]

Hi all,

On my home lab i had 2950T  switch which was in VTP transparent mode.

i change it to VTP mode client and removed the vlan.dat file from flash.

i did as i was knowing that vtp mode client do not save their config and they get vtp updates from vtp server.

after reboot switch came back to transparent mode?

can anyone tell me why  switch came back to transparent mode?

950T#sh vtp status
VTP Version                     : 2
Configuration Revision          : 0
Maximum VLANs supported locally : 250
Number of existing VLANs        : 6
VTP Operating Mode              : Transparent
VTP Domain Name                 : manveer.com
VTP Pruning Mode                : Disabled
VTP V2 Mode                     : Disabled
VTP Traps Generation            : Disabled
MD5 digest                      : 0xA2 0x5F 0xD7 0xB2 0x13 0x6B 0x4E 0x85
Configuration last modified by 0.0.0.0 at 0-0-00 00:00:00

thanks

mahesh

[ajay chauhan]

clear the vlan.dat and reload the router then change VTP mode.

Thanks

Ajay

[mahesh18]

Hi ,

Thanks for reply.

i did few times same reult.

[Chad Peterson]

What happens if you just move to client w/o reload...does it show as client in 'show vtp'?

Also can you send 'show vlan'.  Need to make sure your not using any extended vlans to be in client mode

[mahesh18]

Hi Chad,

I heard that when vtp is in client mode it has  does not store vlan config.

but in my  case it shows   as below

2950T#sh  vlan

VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Fa0/1, Fa0/2, Fa0/4, Fa0/5
                                                Fa0/6, Fa0/7, Fa0/9, Fa0/11
                                                Fa0/12, Fa0/13, Fa0/14, Fa0/15
                                                Fa0/16, Fa0/17, Fa0/22, Fa0/23
                                                Fa0/24, Gi0/1, Gi0/2
10   VLAN0010                         active    Fa0/3, Fa0/10, Fa0/18, Fa0/19
                                                Fa0/20, Fa0/21
20   VLAN0020                         active
30   VLAN0030                         active
1002 fddi-default                     act/unsup
1003 trcrf-default                    act/unsup
1004 fddinet-default                  act/unsup
1005 trbrf-default                    act/unsup

VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
1    enet  100001     1500  -      -      -        -    -        0      0
10   enet  100010     1500  -      -      -        -    -        0      0
20   enet  100020     1500  -      -      -        -    -        0      0
30   enet  100030     1500  -      -      -        -    -        0      0

VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
1002 fddi  101002     1500  -      -      -        -    -        0      0
1003 trcrf 101003     4472  1005   3276   -        -    srb      0      0
1004 fdnet 101004     1500  -      -      -        ieee -        0      0
1005 trbrf 101005     4472  -      -      15       ibm  -        0      0

VLAN AREHops STEHops Backup CRF
---- ------- ------- ----------
1003 0       0       off

Remote SPAN VLANs
------------------------------------------------------------------------------

Primary Secondary Type              Ports
------- --------- ----------------- ------------------------------------------

2950T#sh vtp sta
2950T#sh vtp status
VTP Version                     : 2
Configuration Revision          : 19
Maximum VLANs supported locally : 250
Number of existing VLANs        : 8
VTP Operating Mode              : Client
VTP Domain Name                 : manveer.com
VTP Pruning Mode                : Disabled
VTP V2 Mode                     : Enabled
VTP Traps Generation            : Disabled
MD5 digest                      : 0x1D 0xE3 0x27 0x9A 0x5F 0xD1 0xC5 0xAA
Configuration last modified by 192.168.10.1 at 1-21-11 17:45:57
2950T#sh flash
2950T#sh flash:

Directory of flash:/

    2  -rwx     3721946  Feb 28 1993 17:32:40 -07:00  c2950-i6k2l2q4-mz.121-22.EA13.bin
    3  -rwx         756  Jan 24 2011 12:45:16 -07:00  vlan.dat
    4  -rwx          24  Jan 24 2011 11:53:39 -07:00  private-config.text
    5  -rwx        3933  Jan 24 2011 11:53:39 -07:00  config.text
    8  -rwx         316  Feb 28 1993 17:33:03 -07:00  env_vars
   19  -rwx         109  Feb 28 1993 17:03:50 -07:00  info
   20  -rwx         109  Feb 28 1993 17:03:50 -07:00  info.ver

7741440 bytes total (4011008 bytes free)

thanks

mahesh

[Chad Peterson · Accepted solution]

Hi Mahesh,

This looks right. When VTP is in Client mode it does still show the vlan config when doing 'show vlan'. This data is stored in the vlan.dat file. The different is that vtp transparent stores the vlan config in the running configuration. I'm going to guess this is what was meant when you heard that client doesn't store the config.

Client stores the full vlan config. In fact if it were to happen to have the highest revision number, other switches would update their vlan config to match what was on the client switch.

VTP client and VTP server mode are nearly identical, except for changes to the vlan config can ONLY be made on servers.

I hope that clears it up.

Chad

[mahesh18]

Hi chad

thanks for reply

i did test on vtp client mode

from vtp client switch i unplug all connections to server switch and  did reload it came back showing all the vlans and vlan.dat file in flash.

then i did second test.

i delete the vlan.dat file from flash did the reload and it came back without vlans and no vlan .dat  file in flash.

so what does this show?

does it store  vlan and vtp info in nvram  or  flash??????

regards

mahesh

[Chad Peterson]

So in Client mode vlan config will be saved on your flash in the vlan.dat file.

[Chad Peterson · Accepted solution]

Also you can check this out as well:

http://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080094c52.shtml

The Other VTP Options sections explains the three modes.

Chad

[mahesh18]

Hi Chad,

Many thanks for  reply

regards

mahesh