Vlans on VTP Clients

Unanswered Question

I have 3 3560 Series Routers. 1 is configured as a server and the other 2 as Clients. I created VLAN 2 on the server and assigned it a name and an IP address. I can see the VLAN on the clients by doing a show vlan complete with name but if I do a show run, there is no mention of a vlan 2. When I try to ping, or send the config file to a TFTP server using the server switch it works beautifully, but when I try to do the same from any of the clients it fails. I think this is because the clients don't have any IP address expicitly for them. I tried ip route [ip address] [subnet mask] vlan 2 in the global configuration but this line doesn't work because there is no vlan 2 on the client.


I can go and make a vlan 2 on the client and give it an IP address, but I shouldn't have to. Could someone please tell me what I am doing wrong, thanks for any help.

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Edison Ortiz Thu, 08/02/2007 - 10:33
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Layer2 Vlans won't be shown in the running config while a switch is on vtp server/client mode.


If you want to create a Layer3 Vlan in the switch, you need to manually create it with


interface vlan 2

ip add x.x.x.x x.x.x.x



Edison Ortiz Thu, 08/02/2007 - 10:43
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You see Vlan2 Layer3 interface. You need to do the same in each switch (different IP address) in order for them to be accessible.


The IP address under Vlan2, belongs to the 'server' switch only. It's not shared among all switches that have Vlan2 in the Vlan DB. You need to create independent Layer3 interfaces.

glen.grant Thu, 08/02/2007 - 12:20
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Without a layer 3 SVI on the clients you cannot manage the client switches , create a layer 3 SVI on each client with a ip address that is in the same range as vlan 2 on your server , if it doesn't have an address its pretty hard to get to it and manage it .

Aren't SVI's used for intercommunication between vlans? Aren't these using the same vlan. What is the difference between typing the two commands "vlan 2" and "int vlan 2"

from the configuration menu. "vlan 2" denies me access because I am a client, and I am allowed to do "int vlan 2" and give it an IP address and such.

Jon Marshall Mon, 08/06/2007 - 09:18
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David


The confusion is between layer 2 & layer 3.


You created a vlan at layer 2 on the VTP server. This will propgate to the VTP clients so when you do a "sh vlan" on the clients you can see vlan 2.


On the VTP server you have a layer 3 interface with an ip address for vlan 2.


But on your VTP clients you do not. Unlike the layer 2 information which is propogated via VTP the layer 3 information must be configured on each switch.


SVI's are used for inter-vlan routing on a layer 3 switch. But even if the switch is just a layer 2 switch it still needs one SVI, not for inter-vlan routing but for management.


So if you want your VTP client switches to be bale to download configs to a tftp server they will need an SVI to be able to communicate. The default gateway on the VTP clients should be the IP address of vlan 2 SVI on the switch that does the intervlan routing.


HTH


Jon

Thanks for the help, its becoming clearer now. How do I go about making this SVI?


Also, Im starting to realize that VTP maybe a bit of an overkill, I dont plan on making anymore vlans and there will only be 3 switches. Is there a problem with routing everything using the default vlan1? I heard that its bad practice to lay your data on top of the Cisco traffic that is on VLAN 1, thanks again for the help.


Jon Marshall Mon, 08/06/2007 - 10:33
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Hi


to create an SVI on a switch


interface vlan "vlan number"

ip address x.x.x.x "subnet mask"

no shut


You can use vlan 1 if you want but it is recommended to use a different vlan number.


HTH


Jon

Edison Ortiz Mon, 08/06/2007 - 09:21
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Correct, SVIs are used for inter-vlan routing but they are also used for IP connectivity to the switch.


The differences between vlan2 and int vlan2 are; with the first one, you care creating a vlan in the switch. This need to be done on a VTP server which is the switch holding the Vlan DB. On the second command 'int vlan 2', you are creating a Layer3 interface that represents that Vlan on that switch. You are allowed to do so on any switch as long as the Vlan is created on its database.


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