New Site - Architecture question

[30362]

We are building a new facility and will be migrating our corporate headquarters along with several smaller buildings into one location. I have purchased two 3750G-24T switches for my mdf and 3550-24 switches for each IDF, along with a second 3640 router that I intend to use to better distribute the circuit load and provide redundancy.

In each IDF I will connect the 3550s using a gigastack cable, and then using copper Gbics in the remaining Gbic port on the top and bottom switch in the stack I will connect each Gbic to a gigabit port on the 3750s in the MDF, one on each 3750 to provide redundancy.

In the MDF I planned on multi-homing each server, with 1 gigabit link to each 3750.

Now comes my question - I would like to segment each floor of the building (3 total) into separate subnets for the purpose of DHCP assignment etc... Should I use my 3640 router with multiple FastEthernet ports to do the segmentation or is there a better way - I am confused on how to best do this since I will be running two connections from each IDF back to separate switches in the MDF.

Any help would be greatly appreciated.

 

[baddos]

Please do a "show vtp status" on your 3550 that is setup with the trunking. Also, you might want to manually set the encapsulation to either 802.1q or isl.

 

[lui3]

the 3550 will not be able to ping the interface of vlan 103 unless it too has an ip address in that vlan.

 

[30362]

rburke - in your example above where you recommend connecting the 3640s with /30 links, I am trying to assign an IP address to the gigabit port on the 3750 side of that configuration and get the following error : "IP addresses may not be configured on L2 links".

How do I fix this?

 

[30362]

rburke - ok, I think I found the answer, I can use the "no switchport" command to set a port to L3, but now I am curious how I would put all 4 of those /30 connections back to my routers into their own VLAN? Can I still use the "switchport access vlan 5" command if I have used the "no switchport" command?

 

[baddos]

30362.... You want 4 different /30 connections to be in the same VLAN?

I am asuming you will have 4 connections connected to your 3640, and the 3640 is in vlan 5.

 

[30362]

baddos - I have 4 different /30 connections from the switch back to my two 3640s, however to assign an IP address to a port on the switch I have to make it a layer3 port with the "no switchport" command which then prevents me from placing those 4 switch ports into a vlan...

 

[baddos]

Correct... That is by design.

You can't be in a VLAN and be a layer3 interface at the same time. They only use layer3 interfaces for connecting to other routers, etc.

 

[30362]

baddos - as I expected, thanks for the confirmation. I assume that I should treat it like a router and let EIGRP determine the metrics for the best route...