VTP Version 3 Problems

[CSCO12071332]

Good day,

I got a problem using VTP version 3.

I have 3 Cisco switches:

     - WS-C3750X-48T-S (c3750e-universalk9-mz.122-53.SE2.bin)

     - WS-C2960-8TC-L (c2960-lanbasek9-mz.122-58.SE2.bin)

     - Cisco 3560G (c3560-ipservicesk9-mz.122-58.SE2.bin)

Before I had older versions of IOS, but I updated them, because devices did not support VTP version 3.

Moreover, I have checked compatibility of these switches and IOS with the named above technology via Cisco Feature Navigator.

When I am trying to create vlan on VTP version 3 mode, I get the message shown below:

SHM_BG_SW1(config)#vlan 30

VTP VLAN configuration not allowed when device is not the primary server for vlan database.

I know from Cisco documentations that in order to be able to create vlans, switch should be int the primary server mode.

However, vtp primary-server [vlan | mst] [force] command does not works:

SHM_BG_SW1(config)#vtp ?

   domain     Set the name of the VTP administrative domain.

   file            Configure IFS filesystem file where VTP configuration is stored.

   interface    Configure interface as the preferred source for the VTP IP updater address.

   mode         Configure VTP device mode

   password   Set the password for the VTP administrative domain

   pruning      Set the administrative domain to permit pruning

   version      Set the administrative domain to VTP version

Moreover, when working swithces use VTP version 3, already existing VLANs do not update, VTP advertisements dropped or do not propagate at all.

I do not know what to do with this issue.

Is it possible that vtp primary and secondary server modes only work on Cisco 4500 and 6500 switches?

Why do I faced these problems? I could not find the answer from the forums and Cisco papers.

Devices were tested on laboratory conditions, but I work for a big company and we need to use VLAN numbers which are greater that 1000.

Therefore, it is really important for me to implement VTP version 3.

Is there any probability of the network outage, when we will migrate from VTP version 2 to 3?

Thanks in advance.

Best Regards,

Almaz

[paolo bevilacqua]

Wrong forum, try "infrastructure - lan switching". You can move your post using the actions panle to the right.

However:,

1. there is not need of VTP version 3 to support VLAN ID above 1000, as version2 support that normally.

2. the 'vtp-primary' command must be given in EXEC mode, not config mode.

[CSCO12071332]

Dear Paolo,

I think you are right that I am using different modes for VTP configuration.

Your comment is really helpful, I will try tomorrow to test VTP version 3 again.

However, I disagree with your first statement. Extended VLAN numbers (up to 4095) are only supported by VTP version 3:

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/solution_guide_c78_508010.html

Also I can share number of pages from the official certification guide (CCNP Switch) book.

Anyway if you have an idea how to create and advertise VLAN IDs above 1000 with version 2, please share it.

What about a downtime in the production network, when migrating between these two versions?

Thanks in advance.

[Steven Williams]

extended vlans are supported with vtp version 2 but only in transparent mode, so you are incorrect.

[MOHSIN FAROOQ]

Hi Almaz,

i know its to late to reply, was reading your fourm, earlier i was also geting the same problem once you had,, next time just change the mode into transparent, hopefully it will resolve you problem.

XXXX(config)#vtp  mode transparent

Thanks

Mohsin

[nayef salem]

Hi all

i know it's late to reply too ,

yes extended VLANs are supported in Transparent Mode

and  to overcome the VTP v3 problem

as the first reply said

first make the switch you want as SERVER mode

medical-lab(config)#vtp mod server

use the command in EXEC mode

medical-lab#vtp primary force

then create your VLAN  and name it

i created VLAN 4000 and it worked

go to other Client swtiches and apply   "vtp ver 3  & vtp mod client"

make sure Domain name matches

sometimes for Client switches , make them Transparent and then back again Client to start downloading VLANs from Server

finally    i don't think putting the main switch in transparent mode would help CSCO12071332  as he wants to use VTP and propagate  VLANs to all other switches 

Right!!!

what i don't understand is that SWITCH CCNP book  page 67 says:

Tip: Although the extended range of VLAN numbers enables you to support more
VLANs in your network, some limitations exist. For example, a switch normally maintains VLAN definitions in a special database file, separate from the switch configuration.
The VLAN Trunking Protocol (VTP) uses the VLAN database so that VLAN definitions
can be advertised and shared between switches over trunk links. When extended-range
VLANs are created, they are not stored in the VLAN database file.

so does it mean there are not shared ,, but in my switches 3560x , c3560e-universalk9-mz.122-53.SE2.bin , lanbase license

it worked   and vlan 4000 was propagated to the other switch 3560x also!!!?

[paul]

Way late, but here's the answer:

in vtp v3 extended range vlans are stored in the vlan.dat file.

In vtp v1 and v2, extended range vlans are allowed, but only in transparent mode (effectively, vtp off), and they are stored, not in vlan.dat, but in the running-config.

And yes, thankfully, switch(config)# do vtp primary <cr>  does what's necessary to enable vlan creation thereafter.