Separate 2 VLANs coming from another layer 2 devices

[andre.diawa]

All,

I am pretty new to this forum and I have a good foundation of networking. We are working on a project and your help will be much appreciated. Here is the description of the scenario, I have two traffics coming from different switches (Alcatel-Lucent 7450) and these traffics are vlan-tagged as 120 and 124. So, my goal is to forward these traffic to one Ethernet port or bundle of Ethernet ports of Catalyst 2970 series. I know how to configure that in the following order, Catalyst to Alcatel but in the reverse order I don't have any idea, thus I need your help.

Please find attached the diagram of this scenario, thanks for your help and any guidance.

[Jon Marshall]

Not sure what you are asking.

You say the traffic from the Alcatel switches is tagged so are the ports connecting to the 2970 trunk ports ?

And what bit do you not know how to configure ie. this is a Cisco forum primarily.

Jon

[andre.diawa]

Thanks Jon for your comment. My focus will be on the 2970 not the Alcatel side and I want to know how to configure both traffics coming from another device to be forwarded to any port or bundle of ports of the cisco device.

Andre-

[Jon Marshall]

If the traffic is within the same vlan you just need to create the vlans on the switch and possibly a trunk port to the customer looking at our diagram.

If the traffic is to be routed then you need additional configuration.

It would help if you could explain in a bit more detail what you want to do and also answer the question I asked before.

Jon

[andre.diawa]

The ports connecting to the Alcatel are trunk port. Since that will be a lot of traffics going through that port, I configured as the port channel, using 3 ports of the 2970. Please let me know if it is clear what I am saying because I got confused too about that design.

[Jon Marshall]

That makes sense although not sure why they are trunk ports if they are only passing a single vlan each.

See Julio's last post for configuration example.

Jon

[andre.diawa]

John - you think that configuring these ports are not necessary, I should just leave them as they are. I wanted that these ports to be trunk as traffic coming from Alcatel will be entering to the trunk lines like we can do from traffic going from Cisco to the other brand switch. I will keep you posted what I got by following your suggestion.

[Jon Marshall]

You would need to configure the ports to be in the correct vlans even if you did not make them trunk ports.

If you are passing multiple vlans to each switch then they need to be trunks and it won't make much difference either way so up to you really.

Jon

[Julio E. Moisa]

Hi 

Please correct me if I am understanding wrong, the incoming traffic originated on Alcatel switches will be sent to the Cisco switch then to the customers, do you want to resend the traffic per vlan or specific traffic?

If you have a L2 trunk Etherchannel you should include the Vlans on the trunk configuration (if it is not filtering it will forward them)

[andre.diawa]

Hi Julio,

Thanks for your feedback. Yes, you understood that correctly. In short, I want these traffics - tagged from the other device side as vlan120 and vlan124 - to be forwarded to any ports, to make that pretty simple. And, customers can receive these traffics by connecting to any ports of 2970.

Andre-

[Jon Marshall]

Make sure you create those vlans on the 2970 switch and then just configure the other ports as trunk ports allowing those vlans.

Jon

[Julio E. Moisa]

Thank you Andre,

I got it, if you already tagging the vlans (through a trunk), you need to create the vlan 120 and 124 on the Cisco switch, it could be the configuration using etherchannel or just create interface trunks to connect the Alcatel switches to the Cisco switches, just as comment, if you have only 1 Cisco switch you will have a point of failure, you can evaluate have 2 Cisco switches. 

Example:

Cisco switch to Alcatel 1

vlan 120

vlan 124 

interface g1/0/1 
switchport 
channel-group 12 mode active
switchport mode trunk
No shut

interface g1/0/2 
switchport 
channel-group 12 mode active
switchport mode trunk
No shut

it will create a Po12 interface automatically so you can configure the information under this interface:

int Po12
switchport
switchport trunk encapsulation dot1q  (some devices has the dot1q implicity)
switchport mode trunk
switchport trunk allowed vlan 120  (optional)
no shut

Cisco switch to Alcatel 2

vlan 120

vlan 124 

interface g1/0/3 
switchport 
channel-group 13 mode active
switchport mode trunk
No shut

interface g1/0/4 
switchport 
channel-group 13 mode active
switchport mode trunk
No shut

it will create a Po13 interface automatically so you can configure the information under this interface:

int Po13
switchport
switchport trunk encapsulation dot1q  (some devices has the dot1q implicity)
switchport mode trunk
switchport trunk allowed vlan 124  (optional)
no shut

<asumming Alcatel switches are using dot1q as standard and using LaCP> You could use more ports for the Etherchannel, for example purposes I have just used 2 to connect each Alcatel Switch to the Cisco Switch. 

:-)

[andre.diawa]

Thanks, let me try that and I will keep you posted.

[Julio E. Moisa]

You are welcome, 

Please keep us posted 

:-)