Hi,

It is not designed to handle this role the L3 functions on the switch are designed for it to route between VLANs locally and still connect to a router dedicated for the internet. You may be able to get it to function as an internet router, but your current network design is the recommended method. Here is an non-Dell document on L3 switches versus routers. http://www.dslreports.com/faq/13563

Yes, that would work. If you assign an IP address to one of the interfaces and have the clients point to that and then have a static route or a routing protocol that points to the router, that will work. If it is just a single switch or router than a static route is easier to do than setting up a whole routing protocol. Page 464 http://www.force10networks.com/CSPortal20/KnowledgeBase/DOCUMENTATION/CLIConfig/FTOS/S5000_9.1(1.0)_Config_02-28-2014.pdf

Then the switch will route between VLANs and any requests to the internet will get sent to the static route to the router.

Ok that should reasonable since Layer 3 are set forth for creating inte-Vlan routing inside the lan network.  Would it be possible to keep the Internet Router but take away the Cisco 2600 Default Gateway and use the Force10 as the Default Gateway in addition to the Vlan segment?  Internet router for the internet is one there but why would we use a separate router as a default gateway and a layer 3 core switch. 

Internet router

        |

force10 Layer 3 as Default Gateway / Core Switch for Vlan routing.

would this work with the force10?

You mean assign an ip address to one of the port on the S55 Force10 as the default gateway or set Force10 set ip default-gateway as 192.168.124.6.?   Would this work if i connect the mpls to a sonicwall (nat public to internal) then use one of the sonicwall interface to connect to the core switch (S55 Force10).  

As for the vlan stuff as follows:

spanning-tree mode rapid-pvst
spanning-tree loopguard default
spanning-tree extend system-id
spanning-tree vlan 1-11 priority 8192
!
vlan internal allocation policy ascending
!

vlan 99
 name internet

!
vlan 2
 name Server
!
vlan 3
 name Voice
!
vlan 4
 name Production
!
vlan 10
 name QA_RD
!

interface Port-channel1
 switchport trunk encapsulation dot1q
 switchport mode trunk
!
interface GigabitEthernet0/1
 description * Internet *
 switchport access vlan 99
 switchport mode access
!
interface GigabitEthernet0/2
 description * Server *
 switchport access vlan 2
!

interface GigabitEthernet0/3
 description * voice*
 switchport access vlan

!

interface GigabitEthernet0/4
 description * Production *
 switchport access vlan 4

!
interface Vlan1
 description default
 no ip address
!

interface Vlan99
 description Internet
 ip address 192.168.121.126 255.255.255.128

!

interface Vlan2
 description Server
 ip address 192.168.124.1 255.255.255.128
 ip helper-address 192.168.124.10
!
interface Vlan3
 description Voice
 ip address 192.168.124.129 255.255.255.128
 ip helper-address 192.168.124.10
!
interface Vlan4
 description Production
 ip address 192.168.125.1 255.255.255.128
 ip helper-address 192.168.124.10

You have IP addresses on the VLAN interfaces, so use those IP addresses as the default gateway on each VLAN's clients. Then have a static route to the sonicwall to handle the Internet requests.

I see.  I guess my confusion was that when a vlan set on the core switch, you only give the ip/subnet .  Not sure where the default gateway is being provided from.  I am assuming that the ip helper points to the dhcp server from Active Directory to distribute the gateway.

If the clients are getting their IP addresses from DHCP, then yes that is telling them what the default gateway should be.

thanks Josh.  Very helpful.  I do have a question about the S55 FTO.   i noticed that there's the top rack s55 and then the bottom chassis.  if im not using 10gb switching, it simply would be a single switch with 48 ports correct? 

oops not the S55...i meant the S5000.  If im not using 10GB uplink, there's no need to get all that correct?

That is right, you shouldn't need the extra modules.