3750 switch using OSPF and vlan translation? HELP

[Oliver42]

Hello everyone,

I designed a network that uses 3 switches (2 2950s and one 3750) and 3 vlans (20, 21 and 22). I did inter vlan routing in that network, all users ping each other and so does the switches. I used etherchannels for all connections between my switches. My 3750 needs to have a link with a 3400 that uses only two vlans in its network (100 and 200) and I'm wondering how I'll be able to translate my vlans to the 3400's vlans so I can ping them. How can a ping coming from a PC in my vlan 20 can reach a server on the vlan 200 of the other network? 

My 3750 will be connected to the 3400 with only one cable on one port and I can't configure the 3400. 

Also, I need to use OSPF to tell the other network that uses the 3400 what my own networks/vlans are. How do I configure my 3750 to do OSPF? Just like a router?

Any kind of help is appreciated and I can answer questions any time!
Thank you.

[balaji.bandi]

You need to provide more information :

1. small network diagram of how these devices connected.

2. related configuration of each device to understand?

3. where is your VLAN connected like 20 and 200?

4. I can't configure the 3400. - you do not have access, then how you going to establish OSPF ? - what is this device's role?

[Reza Sharifi · Accepted solution]

Hi,

Connect the 3750 to the 3400 with one link (trunk port) and add vlan 100 and 200 to it. Also create vlan 100 and 200 on the 3750 with an SVI for each. This way the 3750 is the central point of the network and can route between your vlans (20, 21, and 22) and the vlans that are coming from the 3400 (vlan 100 and 200). 

The other option is to keep the 3750 to route between your vlans (20, 21, and 22) and use the 3400 to route for vlan 100 and 200. Now, connect the 3750 to the 3400 with a routed link (layer-3) with a /30 subnet. You can also use SVI for the /30 subnet. Once this is all configured you can use static route between the 3400 and 3750 or use OSPF. The 3750 should support basic layer-3 (OSPF). If you are having issues with OSPF, you can simply use static routes.

HTH

[Oliver42]

I'm not too familiar with the second method you mentionned, but making my 3750 the central point is a good idea. 
I've added OSPF to both my 3750 and the 3400, only adding the 100 and 200 vlan on the 3400 and all of the others on the 3750.

Seems to be working fine for now, but I ran into a problem. 

Everyone can ping the Solarwinds server (upper right), but none of the computers and the 2950s can ping the ESP_ROUTER. I'll have to verify that.

Thanks for your help. 

I