VTP Vlan issue with 3550 and 3560G

[ivanpaseo]

Hi All,

Presently i have encounter a funny issue. My 3560 vtp mode is transparent and 3550 is in server mode. I have manually configure vlan in 3560 as what is it in the 3550. Logically both switches should be able to ping to each other ( i have interface vlan 2 configured on both switch for management).  But this was not the case, i had to configure the 3560 to client mode to grab all vlan details from 3550 than it works. It seems like vlan database on both the switches does not seem to tally. As below is the hardware details and ios. thanks.

System image file is "flash:c3550-i5q3l2-mz.121-12c.EA1/c3550-i5q3l2-mz.121-12c.EA1.bin"

cisco WS-C3550-12T (PowerPC) processor (revision M0) with 65526K/8192K bytes of memory.

System image file is "flash:c3560-ipservices-mz.122-35.SE5/c3560-ipservices-mz.122-35.SE5.bin"

cisco WS-C3560G-24TS (PowerPC405) processor (revision F0) with 122880K/8184K bytes of memory.

[sdheer]

Hi Loh,

If a switch is in a VTP transparent mode it will not accept the uodates from VTP servers.

The switch in VTP transparent mode is not actaully a part of VTP in a sense that it will forward the VTP advertisements but will not act upon it.

That is the reason why the transparent switch in your network didnt take the vlan details from the server.

Hope that answers your query.

Regards,

Swati

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[ivanpaseo]

Hi All

The issue is for the switch in transparent mode, I had already created the vlans as what the VTP server has but yet when the switch is in transparent mode the switch are not able to ping each other. It is only pingable when I changed the mode to client but once I changed it back to transparent the ping drops again and never resume.

Yes my vlan has been created using the command

vlan 2

name management

interface vlan 2

ip address x.x.x.x x.x.x.x

no shut

I suspect it might be a ios bug, as i have tested it on other switches and it work perfectly.

[sdheer]

Hi Loh,

Do you have trunk between the switches which you are trying to ping.

Try disabling VTP pruning and see if that helps.

Regards,

Swati

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[glen.grant]

   How did you create the vlan (what commands)  in the transparent mode switch ?   Did you do a " show vlan" after you created it  and did it show active ?   If you just created the SVI that does not create a layer 2 vlan instance.

[kapathak]

As Glen mentioned,

Did you check the status of the vlan you created in sh vlan br output?

What was the status of the SVI on the transparent switch?

[Peter Paluch]

Hello,

Do you perhaps have the VTP Pruning activated? VTP Pruning works best only if all switches are in VTP Server or Client mode. Use the show vtp status to see whether the VTP Pruning is on. If yes, try deactivating it for a moment (no vtp pruning in global configuration mode) to see if the connectivity issues subside.

Best regards,

Peter