HP Brocade 8/24c HP Virtual Connect: Common Myths, Misperceptions, and Objecti - Page 7

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entire c-Class blade enclosure and makes it behave on the network like a single host running a

hypervisor.

#2: VC Ethernet is really a ProCurve switch and may not be

interoperable with 3rd party network switches

Incorrect:

VC is not a ProCurve switch product and VC is interoperable with any other IEEE

compliant network device.

VC is a product engineered, developed and sold by the HP BladeSystem

division independently of the HP ProCurve division.

VC operates according to IEEE standards and,

like a ProCurve switch, will interoperate with any networking device that is also IEEE compliant.

Virtual Connect provides network-vendor-independent connectivity for an HP BladeSystem c-Class

enclosure.

#3: VC Ethernet doesn’t support Spanning Tree (STP)

Correct:

Much to the delight of VC users, Spanning Tree support on VC is not needed.

VC provides

HP server blade network connectivity just like a hypervisor provides virtual server network connectivity

and neither of these technologies require Spanning Tree support.

VC doesn’t have to support

Spanning Tree just like hypervisor hosts don’t have to support it, yet both provide network redundancy

and load balancing.

Just like a hypervisor host, VC provides network redundancy and load

balancing features that are modeled after NIC Teaming/bonding technology instead of switch

technologies like Spanning Tree.

A Spanning Tree configuration error on any single switch in the

data center can negatively affect any other connected switch in the network, in addition to all servers

connected to the same network.

With Virtual Connect, any redundancy and load balancing

configuration problems only affect a single blade enclosure

1

Fundamentally, VC doesn’t require support for protocols like STP because VC presents itself to the

network as a “termination endpoint”, as does a typical server or a hypervisor host.

VC is not and

does not present itself as a “transit device”, as does a traditional switch.

.

(See response to question 32 for a discussion on loop avoidance.)

#4: VC can cause duplicate MACs and WWNs on the network.

Incorrect:

Virtual Connect Manager (VCM) prevents duplicate MAC addresses and WWNs on the

network for servers in the same VC Domain and Virtual Connect Enterprise Manage (VCEM) prevents

duplicate MAC addresses and WWNs for servers across multiple VC Domains.

Within a VC

Domain, all MACs and WWNs are restricted to a single server port at any one time.

Regardless of

how physical servers are inserted, removed, swapped, or replaced, Virtual Connect prevents the

same Virtual Connect Managed MAC address or WWN from being used on more than a single NIC

or HBA port. A user could introduce duplicate MACs and WWNs on the network by improperly

selecting an address range already in use by another VC domain.

To ensure that this problem does

not occur, customers have the option of using Virtual Connect Enterprise Manager (VCEM) to manage

up to 200 VC Domains

2

In addition ensuring that all VC managed MACs and WWNs are unique, VCEM also provides

automated server recovery and server movement across multiple VC domains.

within the data center.

1

Up to four enclosures if using VC enclosure stacking.

2

Up to 800 enclosures and 12,800 server blades

Section	Page
Abstract	3
Target Audience	3
Prerequisites and Versioning	3
Introduction	3
Myths, Misconceptions and Objections	5
#1: VC Ethernet is just another switch	5
Comparing VC and Server Virtualization Hypervisor Networking Technology	5
A Description of the Hypervisor Components	5
A Comparative Description of the VC Components	6
#2: VC Ethernet is really a ProCurve switch and may not be interoperable with 3rd party network switches	7
#3: VC Ethernet doesn’t support Spanning Tree (STP)	7
#4: VC can cause duplicate MACs and WWNs on the network.	7
#5: VC users cannot leverage existing network management tools (for example, CiscoWorks)	8
#6: VC doesn’t provide secure external management	8
#7: VC Ethernet doesn’t support Private VLANs	8
#8: VC doesn’t provide deterministic load balancing for multiple LACP channels	9
#9: VC Ethernet doesn’t support VLAN Trunking to Server Blade NICs	9
#10: VC Ethernet and Fibre Channel modules require a clunky hardware failure recovery (RMA) process	9
#11: VC doesn’t provide network visibility into the VC Domain for network administrators	10
#12: Many customers experience problems with VC deployment consistency	10
#13: VC doesn’t support non-disruptive firmware upgrades (“hot code load”)	10
#14: HP server blade NICs stay active even after VC Ethernet uplink failure	11
#15: VC is proprietary to HP; VC locks a user to a single blade vendor	11
#16: VC modules form a master/slave relationship with separate IP addresses that aren’t transferred during a failover. When multiple VC modules are present, only one module is elected to forward traffic	11
#17: VC only supports a limited number of VLANs	12
#18: VC Ethernet doesn’t provide Layer 3 routing capabilities	12
#19: VC’s CX4 cables are not ideal for 10Gbe uplinks because of distance limitation	12
#20: VC doesn’t support stacking multiple VC modules	13
#21: VC doesn’t offer Access Control Lists or VLAN Access Control Lists (ACLs or VACLs)	13
#22: VC Ethernet doesn’t support user configurable Quality of Service (QoS) features	13
#23: VC Ethernet doesn’t provide diagnostic tools (SPAN)	13
#24: VC Ethernet doesn’t support the Cisco Discovery Protocol (CDP)	13
#25: VC requires a separate web management window to manage each VC module	14
#26: VC doesn’t support IGMP Snooping	14
#27: VC Fibre Channel doesn’t support nested NPIV	14
#28: Virtualized MAC and WWN (NAT) features on some switches (for example, Cisco’s FlexAttach8F feature) provide the same benefits as VC’s Managed MAC addresses and WWNs	14
#29: DHCP Option 82 provides the same server redundancy features as Virtual Connect	16
#30: VC-FC doesn’t provide login distribution and failover on FC uplinks to the SAN	17
#31: All VC-FC uplinks have to be connected to the same SAN fabric	17
#32: VC-FC does not support Cisco’s VSAN or Brocades Virtual Fabric features	17
#33: VC implements an immature loop avoidance mechanism	18
#34: VC Uplink failures require re-convergence on the external network and may cause dropped server sessions	18
#35: Cisco’s N-Port Virtualization (NPV10F ) or Brocade Access Gateway11F provide all the same advantages as VC-FC	18
#36: Cisco VFrame Data Center provides the same capabilities as VC	18
#37: VC Ethernet can’t be connected to Cisco 6500 switches using Virtual Switching System (VSS)	19
#38: VC Ethernet does not support Unidirectional Link Detection (UDLD)	19
#39: VC Ethernet only provides port counters on uplinks	19
#40: QoS can provide the same functionality of VC Flex-10	20
Unique Features Provided By HP Virtual Connect	20
Managed Server Identities	21
Internal Server Identity	21
External Server Identity	21
Preprovisioning Using Managed Server Identities	21
“LAN Safe” Network Connectivity	22
Consolidate Network Infrastructure with VC Flex-10	22
Server Adds, Moves, and Replacements are Transparent to LAN & SAN	22
Summary of the Virtual Connect Capabilities	23
Additional Resources and References	26
Appendixes	27
Appendix A: Frequently Asked Questions	27

HP Brocade 8/24c HP Virtual Connect: Common Myths, Misperceptions, and Objecti - Page 7

: VC Ethernet doesn't support Spanning Tree STP

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