Is it a must to configure a routed port on 3550 to connect to routers?

[lambent]

I'm going to configure a Cat3550 to use with a VPN gateway. Here is a very simple logical network diagram:

VPN_Client<--ISDN-->Router_A
|
|--VLAN10
|
VPN_GW
|
|--VLAN11
|
Router_B<--VLAN12-->Switch_A
|
|--VLAN13
|
Switch_B

The Cat3550 switch will take the role of VLAN10,11,12,13 and Router_B. So I created 4 VLANs in the switch and created 4 VLAN interfaces with IP address EXCEPT VLAN10 (in this case the Cat3550 will only route VLAN11,12,13, making VLAN10 act like a standalone switch).

I've read some official documents and they said that when connecting a Cat3550 to another router, you have to use the command &quot;no switchport&quot; in a FE interface to make it a routed/layer-3 port before connecting the port to the router. And then add an ip address to the routed port which belongs to the same subnet as the port in the other router.

However in my case, Router_A is connected to a FE port on VLAN10 in Cat3550. To my understanding, this FE port should act as a layer-2 port. So do I still need to use the &quot;no switchport&quot; command and give it an IP address?

Thanks for help.

 

[IPKONFIG]

Your current setup has router A connected via Layer 2 to your 3350 via VLAN 10 (Non-Routed according to you).

From your diagram, I see that your users are coming into Router A which is L2 to your VPN gateway, which I'm assuming is passing/routing to VLAN 11 after authentication and then on to Router B and the rest of your network. If this is the case, then your diagram looks good.

If your VPN gateway does not route, then you need to make the routed interface like Cisco recommends.

Hope this helps.

&quot;I can picture a world without war. A world without hate. A world without fear. And I can picture us attacking that world, because they'd never expect it.&quot;
- Jack Handey, Deep Thoughts

 

[lambent]

Yes VPN_GW will do the routing between VLAN10 and VLAN11.
Thanks for help

 

[JamesLiakos]

Hi.
I know for a fact that 3550's support 2 methods on getting a router connected to them
a) you can make a port a 'no switchport'
b) you can create a vlan on the 3550 and associate it to that physical port.
Hope my info helps you out..