Vlan/Trunk Set up Questions

[coolboarderguy]

Hi All,

I've got 2 switches, 1900 and 2900. I have created a vlan(2) and assigned port f0/2 to it and a trunk on f0/26. I have attached a cross-over cable to port f0/26 and attached a PC(192.168.168.12) to f0/2 with a straight cable. I have attached a straight cable to f0/1 and attached to the Fasteth0/0 port(192.168.168.1) of a 2600 router. On the 2nd switch(2900) I've also created a 2nd vlan(2). My question, is, for the 2nd switches vlan2 to be the same vlan as the 1st switches vlan2, what is required.? Neither of my 2 books show how to assign vlans/port to vlans on 2 switches together. EDIT: Is it that with vtp domain being status on both switches, and with creating a trunk and switch 1 is a server and switch is a client, the vlan2 created on switch 1 will propagate to switch 2.? Allowing the ability to assign ports to vlan2 from the 2nd switch.? Cheers.

UPDATE****

Hi All,

ok, deleted vlan2 on the 2900 switch and set vtp to client. I created a trunk on fa0/1 and attached a crossover cable to it that runs from the 1900's f0/1 which is trunked. But, when doing a show vlan on the 2900 the vlan2 created on the 1900 doesn't appear. What have I not done, or done correctly.? Cheers.

Layout

1900

f0/1 straight cable to 2600's fa0/0

f0/2 assignd to vlan2 and a straight cable attached to PC(192.168.168.12)

f0/26 trunked and a cross-over attached to 2900's fa0/1

vtp = server

vtp dommain = status

2900

fa0/1 cross-over to 1900's f0/26 and trunked

vtp = client

vtp domain = status

2600

fa0/0 straight cable to 1900's f0/1

coolboarderguy...

[amit-singh]

Hi,

First of all, VTP is used for Vlan propagation on your network switches via trunk link. A trunk port is a used to carry the traffic for multiple vlans. IF you have created vlans on your switch which is a VTP server then those vlans will get propogated to your switches which are in the same VTP domain. Now Vlans will get propogated to all the Switches but the ports has be statically configred to their respective vlans which you have to do manually on each and every switch on your network. VTP only passes the Vlan info not the port settings.

For you 1st question, the answer is that you have 2 switches connected with Trunk Link and have the same VLAn info and respective port assingned and the the trunk link is carrying the traffic.

For q2, the answer is tha moment you crated the trunk the VTP infomation was propogated to you 2900 switch and hence you see the Vlan in database.

HTH,

regards,

-amit singh

[coolboarderguy]

Hi All,

thanx, understood, but, I ain't seeing the existence of vlan2 on the client switch when doing a show vlan. How do I confirm the trunk is working.? Cheers.

coolboarderguy...

[amit-singh]

Hi,

You can use the following commands to check that.

First check the interface status using the command " show int fa x/y ".

Then to check the trunk status use the command " show int fa x/y switchport ".

If your trunk is working fine that you will be able to ping between the same Vlans on the diff switches.For example you will be able to ping the Clients on Vlan1 from the Vlan1 Host and the same for the Vlan 2 also and so on..

HTH,

-amit singh

[alejobaltodano]

Hi my friends,

I have a simple question about VLANs and trunking:

Switches A, B and C.

---- trunk lines

====A----B----C====

If A has VLAN2 and C also has VLAN2 is it necessary to create VLAN2 on B? or will data be passed through the trunk lines without a problem?

I know it's easy to just create VLAN2 on B, but I'm just trying to understand how this works.

Thanks!

[mahmoodmkl]

HI

As per u r question if u want the vlan information to be propagated to u r switch B verify that if u already have a VTP server running in u r network and u r switch B should be configured as a VTP client.If u dnot have a VTP server then u need to configure one.

Thanks

Mahmood

[mahmoodmkl]

HI

Amit

Amit can u explain me the differences between port-channel ie L2 n L3 and ether-channel i have some misunderstanding in this issues.And what is L3 port channeling.

Thanks in advance

Mahmood

[rodroble]

i hope anyone won't mind me getting in. i haven't read entirely the conversation but the question concerning port-channel in L2 & L3, i don't think there is a L3 port-channeling. As far as what i currently know, port-channel operates only in L2.

I think the reason for this is that L3 can inherently have parallel connections between two L3 interfaces which are part of 2 difft net/subnet (same admin distance or cost would load balance the links). unlike L2 devices which would easily have an L2 loop unless STP is properly configured.