In October Cisco announced second generation Fabric Path technology and a new Nexus 7000 model.  The Nexus 7009 (N7K-C7009 list price is $20,000) is an efficiently designed 14u unit that can house a hefty 336 10GE ports.  The switch is based on a new technology called Fabric 2 which allows the switch to scale to 550Gbps per slot - more than twice that of the Fabric 1 capacity. 

The new Fabric 2 (F2) modules leverage Cisco’s Fabric Path technology.  Cisco NX-OS FabricPath uses layer 3 routing to eliminate scaling limitations of spanning tree networks.  Cisco’s goal is to deliver a unified fabric that combines storage and server networks to create a flatter, simpler, and more manageable design. 

Impressively, Cisco claims that upgrading to Fabric 2 technology takes only 15 minutes with zero downtime.  A NX-OS in service software upgrade is first required before replacing Fabric 1 modules with Fabric 2 modules.  With the maximum of five modules per switch 15 Tbps performance can be achieved.  All Nexus 7009, 7010, and 7018 switches can utilize F2 technology.  However, as seen below, list price for Fabric 2 modules are considerably more expensive than the Fabric 1 module:

• N7K-C7010-FAB-1:  $6,000 List
• N7K-C7018-FAB-1:  $6,000 List
• N7K-C7009-FAB-2:  $12,000 List
• N7K-C7010-FAB-2:  $12,000 List
• N7K-C7018-FAB-2:  $18,000 List

Fabric 2 modules are also backward compatible with all Nexus I/O modules.  However, I/O modules (e.g. N7K-F132XP-15 32 port 10GE module) that run at 230 Gbps with Fabric 1 modules will not run at 550Gbps Fabric 2 speed, but continue at the same speed in the upgraded switch.  Mixed speed modules are supported in the Nexus 7000 as each I/O module runs independently.

10GE port density is achieved with the new F2 I/O module, N7K-F248XP-25 F2-Series 48 Port 10GbE module, which has a list price of $44,000.  Unless one is making a significant investment in 10GE with the new F2 I/O module the high costs of a Fabric 2 upgrade may not make sense. 

Fabric 1 and Fabric 2 cost differentials should also be considered when deciding which model to choose: Nexus 7009 or Nexus 7010.  As noted, Fabric 1 modules are less expensive but are only available on the 7010 and 7018 models.  For instance, a 7010 switch Fabric 1 bundle is 20% less than a comparable 7009 switch Fabric 2 bundle.  If high density 10GE is not essential then the Fabric 1 switch becomes a real possibility especially since Fabric 2 can be added at a future date.