Ethernet Switches & Routers

Brocade FastIron CX - Virtual Stacking configuration (Extended Stack)

by gfcm on ‎05-17-2011 01:30 PM (676 Views)

Background information

Stacking of Ethernet switches is most commonly found in wiring closets of enterprise campus networks. Stacking functionality enables small-form-factor switches to be linked using short copper cables—and then the stack of switches appears and behaves as a single logical switch to simplify management. When a new switch joins the stack, it automatically inherits the configuration of the stack without manual setup.
Stacking switches at the edge of data center networks provides the same value as it does in campus networks. The main difference is that the switches are not physically stacked on top of each other. Instead, longer cables logically unify the switches at the top of each server rack. For example, a row of top-of-rack switches can appear as a single logical switch, significantly reducing management overhead of the data center access layer.

With Brocade IronStack Technology, you can connect up to 8 devices in a stack. You can mix and match every FastIron CX switch in the stack (FCX-S, FCXS-F, FCX-E, FCX-I). You can either configure the CX4 16Gbps ports (default) at the back or the front 10Gbps ports to be used as stacking ports if you need to cover more distance than what is currently supported with CX4 cables (3 meters).

Virtual Stack

As described above FCX-S and FCXS-F devices have two 10 Gbps ports on the front panel and two 16 Gbps ports (CX4) on the rear panel. All of these ports may be used as stacking ports, Virtual stacking is the ability to mix 10Gbps ports and 16Gbps ports to create  a stack of switches over distance(up to 300m between units).However the non-default ports (10 Gbps) must be configured as stacking ports when setting up your FCX-S or FCXS-F IronStack

Equipment used

  • 3 x FastIron FCX that runs FCXR07202.bin (Router Code)

Network Diagram

virtual_stack.jpg

Virtual Stack (Extended Stack) Configuration

  • First, a quick explanation about the port numbering on FastIron CX plateform. Ports are defined according to 3 parameters: STACKID/SLOT/PORT where the slot number is "1" for the standard front ports, "2" for the two default stacking CX4 ports on the rear panel and "3" for the two 10G front ports.

modules.jpg

  • You can see below that by default, the two CX4 ports on the rear panel are configured for stacking:

LeftUp#show stack stack-ports

***** Warning! stack is not enabled. *****

Unit#  Stack-port1      Stack-port2
1      down(1/2/1)      up  (1/2/2)

  • On the left up router, configure the first 10G front port (1/3/1) as well as the second CX4 port (1/2/2) for stacking:

LeftUp(config)#stack unit 1
LeftUp(config-unit-1)#default-ports 1/2/2 1/3/1

LeftUp(config)#show stack stack-ports

***** Warning! stack is not enabled. *****

Unit#  Stack-port1      Stack-port2
1      up  (1/2/2)      down(1/3/1)

  • Configure stacking ports according to the diagram on the two other routers.
  • Once this is done, you can connect the devices together. Then go to the unit that you want to define as the active controller (unit 1 by default).
  • Enable the stack on the intended Active Controller:

LeftDown# config t

LeftDown(config)# stack enable

LeftDown(config)# exit


  • Enter secure-setup command. This command triggers a device discovery process in both directions.

LeftDown# stack secure-setup


  • Then configure a static mac address for the stack. Use a MAC address of a switch from the stack to prevent duplication of MAC address into your network. Without this configuration, the MAC address of the stack will change to the new base MAC address of the Active Controller in case of failover. This could cause a spanning tree root change.

LeftDown(config)# stack mac 0024.3814.1a40

  • Finally enable hitless failover and save the configuration

LeftDown(config)# hitless-failover enable

LeftDown(config)# write mem


  • If you accepted the unit IDs, the stack is formed, and you can see the stack topology using the show stack command:

LeftDown# show stack

alone: standalone, D: dynamic config, S: static config
ID   Type       Role    Mac Address    Pri State   Comment
1  S FCX624SPOE active  0024.3814.1a40 128 local   Ready
2  D FCX624SPOE member  00e0.5200.0100   0 remote  Ready
3  D FCX624SPOE standby 0024.3814.2080   0 remote  Ready

    active       standby
     +---+        +---+        +---+
-2/1| 1 |3/1--3/2| 3 |3/1--3/1| 2 |2/2-
|   +---+        +---+        +---+   |
|                                     |
|-------------------------------------|

Standby u3 - protocols ready, can failover
Current stack management MAC is 0024.3814.1a40

  • The configuration is now consitent across the stack and even across the fiber links:

LeftDown(config)#show run
Current configuration:
!
ver 07.2.02aT7f3
!
stack unit 1
  module 1 fcx-24-poe-port-management-module
  module 2 fcx-cx4-2-port-16g-module
  module 3 fcx-xfp-2-port-10g-module
  priority 128
  default-ports 1/2/1 1/3/1
  stack-port 1/2/1 1/3/1
stack unit 2
  module 1 fcx-24-poe-port-management-module
  module 2 fcx-cx4-2-port-16g-module
  module 3 fcx-xfp-2-port-10g-module
  default-ports 2/2/2 2/3/1
  stack-port 2/2/2 2/3/1
stack unit 3
  module 1 fcx-24-poe-port-management-module
  module 2 fcx-cx4-2-port-16g-module
  module 3 fcx-xfp-2-port-10g-module
  default-ports 3/3/1 3/3/2
  stack-port 3/3/1 3/3/2
stack-port 3/3/1 3/3/2
stack enable
stack mac 0024.3814.1a40
!
!
hostname LeftDown
hitless-failover enable
!
!
!
!
!
!
!
end