vtp transparent

[arvindai]

What I understand from VTP mode transparent is that it will pass the vlan information however it won't replicate the information onto itself. Please see the relevant configuration, why the vlans showing in the show vlan output on switch with transparent mode when the vlans aren't created on it.

Sw#sh vtp status
VTP Version : running VTP1 (VTP2 capable)
Configuration Revision : 0
Maximum VLANs supported locally : 1005
Number of existing VLANs : 12
VTP Operating Mode : Transparent
VTP Domain Name : SERV
VTP Pruning Mode : Disabled
VTP V2 Mode : Disabled
VTP Traps Generation : Enabled
MD5 digest : 0x58 0x3A 0x57 0x1A 0x0B 0xBB 0xDB 0xF5
Configuration last modified by 10.136.123.254 at 0-0-00 00:00:00
Sw#

Sw#sh ip int brief
Interface IP-Address OK? Method Status Protocol
Vlan1 unassigned YES NVRAM administratively down down
Vlan412 10.136.123.254 YES NVRAM up up
FastEthernet0 unassigned YES NVRAM administratively down down


ffeusplsf3-101#sh vlan
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Gi3/1, Gi3/10
22 B89 active Te13/4
23 B31 active Po1
41 VLAN0041 active
100 VLAN0100 active
250 FEG111 active
401 FEGEF active Fa1/38, Gi2/1, Gi2/9, Gi2/13
402 FEG22 active Fa1/9, Fa1/40, Gi2/2, Gi2/15
404 CC44 active
405 RILdfsO active Fa1/2, Fa1/3, Fa1/4, Fa1/5
406 VLAN040556 active
407 FileM active Fa1/29, Fa1/31, Gi4/14, Gi4/15
408 F5 active Gi2/25, Gi2/42, Gi4/39, Gi4/46
409 F5 active Gi9/48
410 VLAN04105 active Fa1/1, Fa1/6, Fa1/7, Fa1/8
412 Vmotion1 active Gi3/19, Gi3/20, Gi3/23, Gi3/24
700 RSPAN active
701 ARM active
800 easynet 5 active
847 VLAN0847 5 active
900 Donovani-DLSW active
996 Pyramid active
997 NetMng active Gi9/33, Gi9/35
998 FFE_Dev active Gi10/13
1000 FFE_Legacy active Gi9/18, Gi10/42
1002 fddi-default act/unsup
1003 token-ring-default act/unsup
1004 fddinet-default act/unsup
1005 trnet-default act/unsup

 

[SweetRevelation]

Why do you think those vlans were never created on it? Which vlans?

Some vlans even have interfaces in them.

Vlan information is stored in vlan.dat on flash, it does NOT just appear in config.

 

[arvindai]

The vlans are not created on this switch. I have given the 'sh ip int output' to validate this statement. The vlans are learnt from somewhere else, only vlan created on this switch is vlan 412.

Sw#sh ip int briefInterface IP-Address OK? Method Status ProtocolVlan1 unassigned YES NVRAM administratively down downVlan412 10.136.123.254 YES NVRAM up upFastEthernet0 unassigned YES NVRAM administratively down down

 

[SweetRevelation]

A VLAN interface and a VLAN are different things.

If you go into config mode and type interface vlan x, you are editing the vlan interface probably so you can manage the switch if it's not a layer 3 switch.

If you are in config mode and you type vlan x, you are adding the vlan to the vlan database which allows you to configure it on ports on the switch.

A number of the vlans configured on your switch have ports assigned to them.

The vlan information is stored in vlan.dat on the switch. (WARNING I AM NOT TELLING YOU TO DO THIS) if you delete the vlan.dat and restart your switch you won't have any vlans and you'll have to configure them again.

How long has this switch been in production? Did you configure this switch or was it already configured?

 

[SweetRevelation]

Also you're running VTP version 1 for some reason, I don't think in Version 1 that a switch in Transparent mode even forwards VTP through it.

 

[SweetRevelation]

Actually that last bit may not be true, I haven't dealt with v1 in a while. But in transparent mode vlans do have to be created on the local switch.

 

[vipergg]

Those vlans are created on that switch and it shows in your that you have a lot of different ports assigned to those vlans .There is a difference between a layer 2 vlan and a layer 3 SVI used to route or manage the switch. If you look at a section you posted you see these ports assigned to all those different vlans. D o show interface status and see what the whole switch looks like . If you don't want any other vlans on there they can be removed just go into config mode and enter "no vlan XX" for each vlan you want to remove . You will then have to assign all your ports into vlan 412 as they are all currently assigned to other vlans.


401 FEGEF active Fa1/38, Gi2/1, Gi2/9, Gi2/13
402 FEG22 active Fa1/9, Fa1/40, Gi2/2, Gi2/15
404 CC44 active
405 RILdfsO active Fa1/2, Fa1/3, Fa1/4, Fa1/5
406 VLAN040556 active
407 FileM active Fa1/29, Fa1/31, Gi4/14, Gi4/15
408 F5 active Gi2/25, Gi2/42, Gi4/39, Gi4/46
409 F5 active Gi9/48
410 VLAN04105 active Fa1/1, Fa1/6, Fa1/7, Fa1/8
412 Vmotion1 active Gi3/19, Gi3/20, Gi3/23, Gi3/24

 

[arvindai]

the above vlans are created on some different switch and I don't know why they are learnt on this switch when its configured to be vtp transparent mode.

 

[vipergg]

It was probably learned at some earlier time set as vtp client or vtp server and learned them then . Just because the switch gets changed to transparent does not get rid of the vlans if they were learned earlier . The fact that there are ports assigned to those vlans indicates this was a conscious decision by someone. Someone has to configure the switch itself in order to assign those ports into those other vlans , that function is not learned but configured by someone.

 

[arvindai]

does that mean the port will work in the vlan if that vlan is created somewhere else and switch is in transparent mode. Also my second question is if I create layer2 vlan in the switch with vtp transparent mode and layer3 vlan is created some different switch and any port in this vlan will be able to communicate with other IPs in the network?

 

[vipergg]

You would have to clarify work . If you have a trunk link to that other switch and those vlans are allowed across that trunk then yes it would talk to that other device and if that other device is a l3 switch with your routing configured then you could could talk to other users in other segments.

 

[VinceWhirlwind]

Arvindai, something to remember is this: VTP and VLANs are two completely different things. You can use VLANs without using VTP. All VTP does is advertise VLANs to neighbouring switches, something you don't need if you configure VLANs on your switches.

So, if you create VLAN2 on Switch#1 but not on Switch#2, then the link between Switch#1 and Switch#2 will not carry VLAN2 as a tagged VLAN until you create VLAN2 on Switch#2 and add it to the link interface on switch#2. You can create VLAN2 on switch#2 manually, or VTP on Switch#2 can create it.

As to your second question, think of your VLAN as a subnet. That subnet is created by creating a layer-3 interface somewhere. The subnet/VLAN can then be extended to other parts of your network by configuring it on additional switches and configuring it on the interfaces that link the switches.