Would VTP Transparent switch support extended VLans?

Hi Experts,

I thought VTP transparent version 2 does not support extended vlans. when I tried to create extended Vlans on the switch, The switch will create the extended vlan number. However, when I say "show vtp status", all of the switches in transparent mode says "maximum vlans locally configured on the switch" is up to 1005 which is the cut off line for Regular Standard vlans.

I just wanted to confirm if it is true that transparent switches will not support extended vlans. If they dont support, why when I create extended vlan number, It gets created? If they do support extended vlan, why "Show VTP Status" will just indicate that this transparent switch supports up to 1005 vlans locally. I have pasted the output below:

SW1(config)#vlan 4094
SW1(config-vlan)#vlan 4000
SW1(config-vlan)#exit
SW1(config)#exit

.....................................................................................................................

4000 enet  104000     1500  -      -      -        -    -        0      0
4094 enet  104094     1500  -      -      -        -    -        0      0


VLAN AREHops STEHops Backup CRF
---- ------- ------- ----------
1003 7       7       off

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


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

SW1#show vtp status
VTP Version capable             : 1 to 3
VTP version running             : 2
VTP Domain Name                 : CCIE
VTP Pruning Mode                : Disabled
VTP Traps Generation            : Disabled
Device ID                       : 0019.55af.7200
Configuration last modified by 0.0.0.0 at 0-0-00 00:00:00

Feature VLAN:
--------------
VTP Operating Mode                : Transparent
Maximum VLANs supported locally   : 1005
Number of existing VLANs          : 10
Configuration Revision            : 0
MD5 digest                        : 0x2B 0x86 0x26 0xB0 0x53 0xE4 0xA4 0x29
                                    0x9B 0x04 0x08 0x35 0x60 0xC3 0x93 0x13

Comments

  • I believe that 1005 figure is the number of VLANs you can configure on the switch, not the VLAN range.  Here is the output from a 2960, which apparently only supports 255 VLANs locally:

    Switch1#show vtp statu
    VTP Version capable             : 1 to 3
    VTP version running             : 1
    VTP Domain Name                 :
    VTP Pruning Mode                : Disabled
    VTP Traps Generation            : Disabled
    Device ID                       : b4e9.b042.6980
    Configuration last modified by 10.1.1.1 at 3-5-93 20:29:45

    Feature VLAN:
    --------------
    VTP Operating Mode                : Transparent
    Maximum VLANs supported locally   : 255
    Number of existing VLANs          : 8
    Configuration Revision            : 0
    MD5 digest                        : 0x49 0x94 0x11 0x51 0x73 0x37 0xA3 0x75
                                        0xEB 0x8A 0xDD 0x7F 0xCC 0xA9 0xFA 0x03

    -Jim

  • Thank you Jim for your quick response and sharing the output from your own switch.

    It makes sense. you are right. In that case, I think transparent switches will support Extended Vlans. "1005" must be just the number of vlans that can get created locally on the switch.

    I did not know that it can be any restrictions on the number of the vlans on the switch. new learning.

    Thanks for your time

     

  • If memory serves, I believe a switch MUST be in VTP transparent mode.  VTP server and client mode won't allow you to use extended VLANs.

    -Jim

  • jfw3 is correct.

     

    VLAN Trunking Protocol Guidelines

    These are the guidelines for using extended VLAN ID with VLAN Trunking Protocol (VTP):

    imageExtended range VLANs are not controlled by VTP.

    imageVLANs in the extended range cannot be pruned. The VLAN range for the switchport trunk pruning vlan command remains 1-1005.

    imageThe VTP supported VLAN configuration (VLANs 1-1005) is included in the Cisco IOS configuration file only when the device is in VTP transparent mode.

    imageVTP learns only normal-range VLANs, with VLAN IDs 1 to 1005; extended-range VLANs are not stored in the VLAN database. The router must be in VTP transparent mode when you create extended-range VLANs.

  • Thank you every body for sharing your feedback. It was learning curve for me. I remember that one part of VTP would not support extended range of VLans but I could not remember which part was that exactly.

     

    You all completed this information.

     

    Thank you

Sign In or Register to comment.