Руководство По Проектированию для Cisco Cisco Nexus 5010 Switch
Design Guide
© 2010 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information.
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In case a given switch topology has not been enabled for vPC port channeling, the other teaming options remain
valid.
valid.
For additional information on network adapter teaming, please refer to Chapter 7.
Unified I/O
This design document focuses on the LAN switch design of the data center with Cisco Nexus products, and not
specifically on the SAN aspects of the design. But because the Cisco Nexus product line is a key enabler for unified
I/O deployments, it is important to be aware of some key Fibre Channel over Ethernet characteristics. What’s more,
the designs that are presented in this document can easily be turned into a unified I/O design.
specifically on the SAN aspects of the design. But because the Cisco Nexus product line is a key enabler for unified
I/O deployments, it is important to be aware of some key Fibre Channel over Ethernet characteristics. What’s more,
the designs that are presented in this document can easily be turned into a unified I/O design.
Here are some of the key technology characteristics that you need to focus on to properly design the data center:
●
The role of the Fibre Channel Forwarder (FCF)
●
The VLAN-VSAN relationship
●
Virtual PortChannel compatibility with virtual Fibre Channel interfaces
●
The support of negotiation protocols, including FCoE Initialization Protocol (FIP) and Data Center Bridging
Exchange (DCBX) Protocol on network adapters
Exchange (DCBX) Protocol on network adapters
FCoE
Fibre Channel over Ethernet (FCoE) is the key technology that enables unified I/O on servers. Unified I/O is the ability
to carry both storage and LAN data traffic on the same network adapter. Although FCoE is not the key topic of this
document, the designs proposed for LAN switching connectivity can be extended to support unified I/O through
FCoE.
to carry both storage and LAN data traffic on the same network adapter. Although FCoE is not the key topic of this
document, the designs proposed for LAN switching connectivity can be extended to support unified I/O through
FCoE.
FCoE (which is referenced as FC-BB_E in the FC-BB-5 specifications) achieved standard status in June 2009, and is
documented in the T11 publication. You can access this publication at:
documented in the T11 publication. You can access this publication at:
.
In the simplest terms, one could say that FCoE is just an encapsulation of Fibre Channel frames into Ethernet frames.
The FCoE model consists of servers with FCoE adapters (E-nodes) normally called converged network adapters
(CNAs), a lossless fabric. A simple way to think of this is as an Ethernet network with the ability to pause FCoE
frames, instead of dropping them, when there is congestion. The model also contains Fibre Channel Forwarders
(FCFs), devices like the Cisco Nexus 5000 Series Switches, which can forward FCoE frames.
(CNAs), a lossless fabric. A simple way to think of this is as an Ethernet network with the ability to pause FCoE
frames, instead of dropping them, when there is congestion. The model also contains Fibre Channel Forwarders
(FCFs), devices like the Cisco Nexus 5000 Series Switches, which can forward FCoE frames.
Starting from the NX-OS Software Release 4.1(3)N1, the Cisco Nexus 5000 Series supports the FCoE standard. A
“prestandard” implementation of FCoE was already available on the Cisco Nexus 5000 Series prior to this release. In
order to distinguish the two, the prestandard FCoE implementation is referred to as pre-FIP, while the standard
implementation is referred to as FIP-compliant (that is, FCoE Initialization Protocol compliant).
“prestandard” implementation of FCoE was already available on the Cisco Nexus 5000 Series prior to this release. In
order to distinguish the two, the prestandard FCoE implementation is referred to as pre-FIP, while the standard
implementation is referred to as FIP-compliant (that is, FCoE Initialization Protocol compliant).
The default class of service assignment for FCoE is 3, and the default bandwidth allocation for FCoE on a CNA card
is 4 Gbps.
is 4 Gbps.
While the current Cisco Nexus 5000 Series hardware is capable of supporting both fabric provided MAC address
(FPMA) and server provided MAC address (SPMA) addressing schemes for FCoE, the software currently supports
the only addressing scheme requested by the standard, which is FPMA.
(FPMA) and server provided MAC address (SPMA) addressing schemes for FCoE, the software currently supports
the only addressing scheme requested by the standard, which is FPMA.
Virtual N-Ports and Virtual F-Ports
When an E-node (that is, a CNA) logs into the FCF (fabric), if the login is successful it establishes VN-to-VF virtual
connectivity whereby the E-node behaves like an N-port and the FCF provides the virtual F-port functionality.
connectivity whereby the E-node behaves like an N-port and the FCF provides the virtual F-port functionality.