09-19-2011 06:29 AM - edited 03-07-2019 02:18 AM
I've used 3750 switches for a long time and the L2 vlan info has always been in vlan.dat. Now it is in the running config. see a portion below.
Why is it in the running config now? It is a Catalyst 3750g-ts-s IOS version 12.2(50)SE5, RELEASE SOFTWARE (fc1)
spanning-tree extend system-id
!
vlan internal allocation policy ascending
!
vlan 2
name Core
!
vlan 5
name FTTH
!
vlan 30
name M_BoE
!
vlan 40
name SE
!
vlan 100
!
!
!
interface GigabitEthernet1/0/1
!
Solved! Go to Solution.
09-19-2011 06:42 AM
It should be because your switch is running in VTP transparent mode. When the switch runs in VTP transparent mode the vlans are written to the running-config as opposed to when running in VTP server/client mode where the vlan info is stored in the vlan.dat file.
Do a "sh vtp status" and you should see the switch is running VTP transparent mode.
Jon
09-19-2011 06:42 AM
It should be because your switch is running in VTP transparent mode. When the switch runs in VTP transparent mode the vlans are written to the running-config as opposed to when running in VTP server/client mode where the vlan info is stored in the vlan.dat file.
Do a "sh vtp status" and you should see the switch is running VTP transparent mode.
Jon
09-19-2011 08:16 AM
Friends,
In fact, the VTP Transparent mode is a bit curious: the VLANs are stored both in vlan.dat and in the running-config. If by some accident, the stored running-config becomes desynchronized from the vlan.dat file (for example, the vlan.dat file is copied to the FLASH from a backup and it differs from the data in the startup-config), the vlan.dat has precedence when the switch boots the next time.
Best regards,
Peter
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