The document provides a detailed overview of Unified Computing System (UCS) architecture, including the two types of servers (rack-mountable and blade servers) and the components involved such as fabric interconnects and management interfaces. It describes the physical architecture and the function of various components, highlighting features like stateless computing, rapid server provisioning, and virtualization readiness. Additionally, it covers connectivity options, port selection for traffic flow, and specifics about the fabric interconnect and its operational modes for SAN connectivity.

2. Two Types of Unified Computing Servers
1. Rack Mountable servers – C Series Servers
2. Blade servers – B Series servers

3. Physical Architecture of UCS - Blade Servers
• Fabric Interconnects ( FIs )
• Core of UCS platform
• Everything connects to FIs
• FIs run the actual UCS Manager software ( XML API )
• Chassis
• Chassis contains blades , but no intelligence
• Blades contains CPU/RAM/CNAs
• IOM / FEX
• IO muxes data from FIs to blades
• CMS ( Chassis management switch )
• Carries management traffic from/to CIMC (Cisco Integrated Management
Controller ) on FI
• CMC ( Chassis Management controller )
• Monitors all sensors , voltage , controls fan speed
• Used in discovery of the chassis , blades and IOMs.

4. Physical Architecture of UCS - Blade Servers

5. Front View UCS - Chassis with Blade Servers & Power Supplies
Half Blade server
Full Blade server
Power supplies
Hard Disk

6. Back View UCS - Chassis with IOMs , FANs & Power Connectors
IOM/FEX
FAN
Power Connector

7. IOM /FEX
Connecting with BUS

8. UCS - Chassis with Fabric Interconnect
Management PortFC/Ethernet Ports
Console Port
FI - interconnect ports

9. Half Blade Server
NIC/CAN Mezzanine Card
Hard Disk
Console
CPU Slots DIM Slots

10. Full Blade Server
Hard Disk
CPU Slots
DIM Slots
NIC/CAN Mezzanine Card

11. • FI – A connects with FI-B with a pair of cables – not for data , but only for
management purpose.
CMS CMS
• CMS are inbuilt in IOM/FEX. CMC on both the IOM/FEX are internally connected
to CMC of each and every blade.

12. • From each VIC/Emulex/CNA card ( mezzanine card ) on the blade a set of links
goes to IOM-A and other set of links goes to IOM-B. No. of Links depends upon
the card type.

13. • Uplinks from VIC to IOM are port channeled by default. The size of the port
channel depends upon the number of ports available on a particular card.
• Traffic from particular Application on VM/ESXi ( through vNIC) can select the
path towards the IOM-A or IOM-B with the concept of vPC Host Mode or MAC
Pinning ( based on source MAC address).

14. • In IOM/FEX ( 2208 XP ) there will be 8 ports facing the FI and 32 ports facing the
blades. Because we have max 8 half blades or 4 full blades in a chassis. On any
card we can have max 8 ports ( 4 towards IOM-A and 4 towards IOM-B ). So 8
blades x 4 ports on each blade = 32 Ports.
• It means that we do have oversubscription ratio of 8:32.

15. Selection of ports for traffic flow from IOM to Fabric Interconnect – Dynamic
Pinning
• If only one link exist than all the blades will send traffic towards that link shown
by red colour.

16. • If two link exist than all the odd number blades will send traffic towards link-1
shown by red colour and the even number blades will send traffic towards link-2
shown by green colour.

17. • If four link exist than the blades 1&5 will send traffic towards link-1 shown by
red colour and the blades 2&6 will send traffic towards link-2 shown by green
colour. Blades 3&7 will send traffic towards link-3 shown by blue colour and the
blades 4&8 will send traffic towards link-4 shown by yellow colour.

18. • If eight link exist than each blade will take as per the below diagram.

19. Selection of ports for traffic flow from IOM to Fabric Interconnect – Port Channel
• In case of port channel the load will be distributed using hash algorithm. No
mapping of particular port with particular blade. This is most recommended
method of deployment. Port channel can be of 2/4/8 ports.

20. Connecting IOM with Fabric Interconnect

21. Benefits Of UCS
1.Stateless computing: server does not have any MAC,WWN,NIC’s,UUID
address,Firmware and BIOS setting all abstracted from UCSM s/w running on FI.
2. Rapid Provisioning of Server: All identity installed from UCSM thus hundred of serevrs can be deploy
with in a days by creating templates.
3. Simplified troubleshooting: As stateless computing thus installing new server abstract all details of old
server from UCSM.
4.Virtualization readiness: Support all major hypervisor platform including VMware
ESXi, Microsoft hyper-V and citrix Xen Server.
5. Choice Of industry Form Factor: Both B-series and C-series server are designed using Intel Xeon CPU.

22. UCS hardware options
Fabric Interconnects
• Provides network connectivity (both LAN and SAN) and management of connected server.
• UCSM lies inside fabric interconnect can access through management interface.
• Core component of UCS Solution.
• Support all FCoE,FC and ethernet ports.
• FI are deployed in clustered pairs to provide high availability(Active-Active topology)
6100 series FI
1.UCS 6120XP: -20 10GE/FCoE ports in 1 RU.
-One expansion slots
2.UCS 6140XP: -40 10GE/FCoE ports in 2 RU.
-Two expansion slots

23. 6200 series FI
1.UCS 6248UP: -32 fixed Unified ports w and 1 RU space.
-One expansion slots
-Support 20 blade chassis per FI
1.UCS 6296UP: -48 fixed Unified ports w and 1 RU space.
-Three expansion slots
-Support 20 blade chassis per FI

24. 2204XP IOM/FEX
2208XP IOM/FEX
2104XP IOM/FEX
• Older Model
• 4 10 Gbps to FI
• 8 10 Gbps to Server
• 40 Gbps through put
• 2nd generation
• 4 10 Gbps fabric port to FI.
• 16 10 Gbps server facing ports with FCoE.
• 40 Gbps through put
• 2nd generation
• 8 10 Gbps fabric port to FI.
• 32 10 Gbps server facing ports with FCoE.
• 80 Gbps through put

25. Blade Servers

26. Rack Servers

27. Mezzanine adapters- from Cisco

30. Mezzanine adapters – from other Vendors

31. IOM/FEX Comparison with Mezzanine adapters (VIC)

32. Physical Architecture

33. Physical Architecture-with C-series Integration

34. LAN Connectivity

35. Connectivity – Components and LAN
UCS Ports Defined

37. Connectivity –Components and LAN
Northbound of the Fabric Interconnect

38. 1. No spanning-tree protocol (STP); no blocked ports.—Simplified Upstream Connectivity.
2. Admin differentiates between server and network ports.
3. Using dynamic (or static) server to uplink pinning.
4. No MAC address learning except on the server ports; no unknown unicast flooding.
5. Fabric failover (FF) for Ethernet vNICs (not available in switch mode).
End-host mode (EHM): Default mode
Fabric interconnect

40. Fabric Interconnect –Ethernet EHM -Unicast Forwarding

48. GARP A,B,C

52. End Host Mode Unicast Forwarding
RPF:unicast/multicast traffic is forward to server only if it arrives on correct pinned uplink port.
Deja-vu-check: Packet with source mac-address to a server received on an uplink port is dropped.

53. 1. Fabric Interconnects behave like regular ethernet switches.
2. STP configured for loop avoidance.
3. The uplinks ports are configured as forwarding or blocking as per the STP algorithm.
4. Not a default mode of operation.
Fabric Interconnect – Ethernet Switch Mode - Overview

54. Northbound of the Fabric Interconnect – Ethernet Switch
Mode - Overview

55. Designated Broadcast/Multicast Uplink Ports
• For any Broadcast/Multicast southbound traffic from N5K moving downward toward UCS Fabric Interconnects ,there
has to be a designated port on FI-A and FI-B.
• Suppose UCS FI-A chooses Po1 as its designated Broadcast/Multicast traffic receiver Port.
• Suppose UCS FI-B chooses Port 1/19 as its designated Broadcast/Multicast traffic receiver Port.
• Any Broadcast/Multicast traffic coming from N5K to UCS FI , but not on the defined as designated
Broadcast/Multicast ports will be dropped.
• Outgoing Broadcast/Multicast traffic is allowed on all the ports.

56. Blade server-1
   
Broadcast/Multicast Traffic
• Any incoming Broadcast/Multicast traffic is allowed only on designated Broadcast/Multicast ports only
and will be dropped on any other ports. This is to avoid loops as no STP is running .
• Outgoing Broadcast/Multicast traffic is allowed on all the ports.
Blade server-2

57. • Suppose UCS FI-B chooses Port 1/19 as its designated Broadcast/Multicast traffic receiver Port.
• vNIC2 ( having mac 00B1 ) is pinned to UCS FI-A uplink 1/17
• Any Broadcast/Multicast outgoing traffic coming from Server -1 vNIC 2 to UCS-F1-A will be blocked at all the ports on UCS FI-B except
1/19 .
• Any Broadcast/Multicast outgoing traffic coming from Server -1 vNIC 2 to UCS-F1-A and then again coming back to UCS FI-A via N5K1
to Po1 will also be dropped. This is called Deja-Vu Check (If I have seen that traffic(src-mac address) before ……drop it). This prevents
the loop.

58. Blade server-1

Blade server-2
1/191/17
OOB1

Po1

59. Key Points
1. Server vNIC pinned to an uplink port.
2. NO STP Protocol.
3. Maintains Mac table for server only not entire data center.
4. Prevent loops by preventing Uplink-to-uplink switching.
5. Upstream VPC/VSS optional(Best practice).
6. Server-to-Server traffic on the same vlan switched locally.

60. Recommended Topology for Upstream Connectivity
Always dual-attach each fabric interconnect to two Cisco Nexus 7000 Series Switches for high availability and redundancy whether
using vPC uplinks or individual uplinks without vPC.

61. Connectivity –SAN

62. Connectivity –SAN
FI Modes of Operation -SAN
N_Port Virtualisation(NPV) Mode : Default, recommande mode
1. UCS relays FCIDs to attached devices –No domain ID to maintain locally
2. Zoning, FSPF, alias etc. are not configured on the UCS Fabrics
3. Domain Mgr., FSPF, Zone Server, Fabric Login Server, Name Server do not run on UCS Fabrics.

64. SAN Fabric Interconnect FC/FCoE Mode of Operation –Switch Mode
1. UCS Fabric Interconnect behaves like an FC fabric switch.
2. Storage ports can be FC or FCoE.
3. Local Zoning OR Upstream Zoning(Upstream Zoning Provided by MDS/N5k).
4. Fabric Interconnect uses a FC Domain ID.
5. Supported FC/FCoE Direct Connect Arrays.

65. Direct connected Array

66. Connectivity –SAN Multi-hop FCoE–UCS to 5K –FCoE Uplinks

67. Connectivity –SAN Multi-hop FCoE–UCS to 5K -Converged Uplinks

68. Connectivity –SAN Multi-Hop FCoE–UCS to MDS –FCoE Uplinks