Cisco NX-OS Data Center Features - PowerPoint Presentation

Slide1

Cisco NX-OS Data Center Features

Jack RossCCIE #16728

1Slide2

Agenda

Brief Hardware OverviewSoftware Versions

NX-OS Layer 2

NX-OS Layer 3

FabricPathVirtual Device Contexts (VDC’s)Fiber Channel Over Ethernet (FCoE)Overlay Transport Virtualization (OTV)Virtual Port Channels (vPC’s)

2Slide3

Nexus 7000 Overview

Nexus 7000/7700

–

Typically DC core or aggregation

– High performance, density, & availability – Unified I/OFCoE switch but not a FC switch – Redundant Power, Line Cards and Supervisors3Slide4

Nexus 7000 Platform Overview

• Currently 7 form factors

–

7018, 7010, 7009,

7004, 7718, 7710,7706• Currently 2 types of line cards – M Series Cards - Layer 3 cards • Feature rich cards – F Series Cards - Layer 2 cards* • Performance oriented cards

4Slide5

Line Card Features

• M Series Specific – Layer 3 Routing

–

FEX

– OTV – TrustSec• F Series Specific – FabricPath – vPC+ –

FCoE

5Slide6

Nexus 5000 Overview

Nexus 5000/5500

– Typically End of Row (

EoR

) aggregation or Top of Rack (ToR) access– Typically Layer 2 but can do limited Layer 3 with add on daughter card in the 5500 Series Unified I/O– Both FCoE and native FC switching– Redundant power but not

supervisors

6Slide7

Nexus 5000 Platform Overview

• Currently 2 Generations

–

1st Gen - Nexus 5000 – 5010 & 5020

– 2nd Gen - Nexus 5500 – 5548 & 5596• Mainly layer 2 switching – 5500 can support L3 add-in card• Supports Unified I/O – Both FCoE Forwarder (FCF) and native FC switching• 5500 supports Unified Ports (UP models)

–

Ports can run as Ethernet or native

Fibre

Channel

–

Ethernet ports allocated at port 1 and counts up

–

Fibre

Channel ports allocated at last port and counts down

–

Requires a reboot to re-allocate port’s role (like UCS FI)

7Slide8

Nexus 2000

• Fabric Extender (FEX)• Acts as a remote line card of 7K or 5K chassis

• All management performed on Parent Switch

– No console or VTY ports on FEX

– NX-OS automatically downloaded from Parent• No local switching– Essentially a VN-Tag/802.1BR switch, not an Ethernet switch– Traffic between local ports on FEX must flow “north” via uplink to Parent and then “south” back down– Can impact design decision of platform placement

8Slide9

Software Versions for CCIE Lab

• NX-OS v6.0(2) on Nexus 7000 Switches (6.2(6) latest)

• NX-OS v5.1(3) on Nexus 5000 Switches

• NX-OS v4.2(1) on Nexus 1000v

• NX-OS v5.2(2) on MDS 9222i Switches• UCS Software release 2.0(1x) for UCS-6248 Fabric Interconnect9Slide10

Nexus NX-OS Basics

Nexus at its core is a Layer 2/3 SwitchSimilar

in many aspects to Catalyst IOS

–

VLANs, Trunking, VTP, Rapid PVST, MST, EtherChannel, PVLANs, UDLD, FHRPs, IGPs, BGP, etc.Key new features beyond Catalyst IOS – FEX, vPC

, Fabric Path, OTV

,

FC Switching,

FCoE

,

etc

10Slide11

NX-OS Port Channels/EtherChannels

• Unlike IOS, NX-OS does not support

PAgP

–

Channels must be statically on or LACP negotiated no “switchport mode desireable” – LACP must be enabled with feature lacp

• One of the “killer apps” of NX-OS is

Virtual Port Channels

(

vPC

)

–

Multi-Chassis

EtherChannel

(MEC/MCEC)

–

Analogous to 3750 Cross

StackWise

Channel & 6500

Virtual Switching System (VSS)

11Slide12

NX-OS Spanning Tree

• Unlike IOS, NX-OS does not support legacy CST/PVST+

–

Default STP mode is Rapid-PVST+

– i.e. per-VLAN, but uses 802.1w Rapid STP – Also supports 802.1s Multiple Spanning Tree (MST)• NX-OS defines three STP port types– spanning-tree port-type [normal | edge | network]

12Slide13

NX-OS Switchport

Typesspanning-tree port-type normal

–

Normal ports act like Catalyst IOS ports

– Default STP port type, run Rapid Per VLAN STP spanning-tree port-type edge – Edge ports are STP PortFast portsspanning-tree port-type network – Network ports run STP Bridge Assurance

13Slide14

Bridge Assurance

• All STP Network Ports send BPDUs regardless of STP port state

–

Legacy 802.1d only sends BPDUs from Root Bridge

downstream – Primary goal is to protect against unidirectional links – BPDU becomes a bidirectional keepalive – Replaces LoopGuard functionality

• Secondary result is same functional effect as VTP Pruning

–

VLANs stop forwarding on

trunk links

that you do not receive BPDUs

for that

VLAN in

• Enabled on interfaces with

spanning-tree port type network

14Slide15

Bridge Assurance Diagram

15

switchport

trunk allowed

vlanSlide16

NX-OS Layer 3

Like Catalyst IOS, NX-OS supports…

–

Native layer 3 routed

interfaces I.e. no switchport Switched Virtual Interfaces (SVIs) • I.e. VLAN interfaces •

Must be enabled with

feature interface-

vlan

16Slide17

NX-OS Routing Protocols

• Like IOS, NX-OS supports routing with… –

Static routing

–

RIPv2 & RIPng – EIGRP & EIGRPv6 – OSPF & OSPFv3 – IS-IS – BGP – Policy Routing

– No network command in IGP’s, activated on link

• Not all protocols use the same

license

17Slide18

NX-OS VRF

• Like IOS, NX-OS Virtual Routing & Forwarding Instances are used to

create separate logical routing tables

–

Layer 3 interfaces in different VRFs cannot exchange traffic by default• NX-OS VRFs behave slightly different than IOS, as… – All layer 3 interfaces are automatically in VRF table “default” – MGMT0 is automatically in vrf “management” – VRFs are defined as vrf context

–

Static routes are defined under the

vrf

context

–

Dynamic routing is VRF aware, but configured under the

same process

–

Exec mode

routing-context

vrf

can change the default VRF

for verifications

18Slide19

NX-OS Redistribution

• Unlike IOS, route-maps are required

to perform

redistribution on NX-OS

– Same route-map match/set logic as IOS• Redistribution does not include directly connected interfaces – Requires

redistribute direct route-map

…

19Slide20

Fabric Path

Pre Standard version of TRILLEssentially Layer 2 Ethernet Routing

Uses ISIS to route Layer 2 Frames instead of using STP

Can build arbitrary Topologies – Full Mesh, Partial Mesh, Triangle, Square,

etcAdds a TTL in Layer 2When using with vPC referred to as vPC+20Slide21

Fabric Path Configuration

• Very few commands necessary• Enable FabricPath

–

install feature-set fabricpath – feature-set fabricpath• Configure FabricPath VLANs – mode fabricpath under VLAN

• Configure

FabricPath

Core Ports

–

switchport

mode

fabricpath

21Slide22

Virtual Device Contexts (VDC)

VDCs used to virtualize physical hardware

of Nexus

7000

– Loosely analogous to SDRs in IOS XR or Contexts in ASA• VDCs also virtualize control plane protocols of Nexus 7000 – Not analogous to VLANs or VRFs in IOS – Separate control plane per VDC

•

VLAN

40

in VDC 1 is not VLAN

40

in VDC 2

• OSPF PID

20

in VDC 1 is not OSPF PID

20

in VDC 2

22Slide23

Why VDC’s?

Multiple logical roles per physical

chassis

– E.g. Core & Aggregation/Distribution on same box

Multi-Tenancy– E.g. VDCs as a managed service to customersTest Lab Environment for later Production UseRequired for certain features – FCoE

/Storage

23Slide24

VDC Caveats

Some features can’t co-exist in same VDC – OTV and VLAN interfaces (SVIs)

–

F2 cards and M1/F1

– FCoE requires its own “Storage” VDCHardware and Software version dependent, check the release notes

24Slide25

VDC Maximums

• 4 VDCs per chassis with SUP 1• 4+1 VDCs per chassis with SUP 2

• 8+1 VDCs per chassis with SUP 2E*

• No internal cross VDC communication

– E.g. no route leaking like in VRFs – Physical cable can be used to connect VDCs25Slide26

The Default VDC

• Default VDC “1” always exists and cannot be removed• Used to create and manage other VDCs

–

Controls VDC port allocations

• All ports allocated to default VDC at initialization – Controls VDC resource allocations• Number of VLANs, VRFs, Routing table memory, etc.• Can be used for normal data plane operations – “Recommended” for management of chassis only

26Slide27

Default VDC Tasks

Some tasks can only be performed in the default VDC –

VDC creation/deletion/suspend

–

Resource allocation – interfaces, memory, MAC’s – NX-OS Upgrade across all VDCs – ISSU or EPLD Upgrade – Ethanalyzer captures – control plane traffic – Feature-set installation for Nexus 2000,

FabricPath

,

FCoE

–

Control Plane Policing (

CoPP

)

–

Port Channel load balancing hash

–

Hardware IDS check control

–

ACL Capture feature enable

–

System-Wide

QoS

27Slide28

Converged Ethernet or FCoE

• Lots of terms that essentially mean the same thing

– Unified Fabric

– Unified Wire

– Converged Ethernet – Converged Enhanced Ethernet

– Data Center Ethernet

– Data Center Bridging

• What they all really mean…

– You are

running the physical framing for both

Ethernet and

Fibre

Channel over the same physical links

28Slide29

FCoE Terms

• FCoE Initialization Protocol (FIP)

•

FCoE

Forwarder (FCF)• ENode – End Device• Virtual Fibre Channel (VFC) Interface29Slide30

FC, FCoE

, FCIP and iSCSI

30Slide31

How FCoE

Works

FCoE

replaces layer 1 & 2 transport for FCAll upper layer FC services remain – Domain IDs, FSPF, FCNS, FLOGI, Zoning.• New FCoE

Initialization Protocol (FIP)

to negotiate between

Fabric and

Node

– Fabric is the FCF

– Node is the

ENode

31Slide32

FCoE Control and Data Planes

• FIP is the control plane of

FCoE

•

FCoE is the actual data plane

• FIP

– New

EtherType

0x8914

– Used to discover FCFs and perform FLOGI

_ UCS C when

FCoE

turned on uses LLDP to begin negotiation

•

FCoE

– New

Ethertype

0x8906

– Min length of 2240 bytes, FC has larger payload

• Implies Jumbo Frames are required

32Slide33

OTV Basics

• Overlay Transport Virtualization (OTV) –

Layer 2 VPN over IPv4

• Specifically OTV is…

– IPv4/IPv6 over Ethernet… over MPLS… over GRE… over IPv4…33Slide34

OTV vs. other Layer 2 DCI’s

Layer 2 DCI is needed for Virtual Machine Workload Mobility i.e. VMware

VMotion

•

Many possible options for L2 DCI – Dark Fiber (CWDM/DWDM) – Layer 2 Transport Protocol (L2TPv3) – Any Transport over MPLS (AToM) – Virtual Private LAN Services (VPLS)

–

Bridging over

GRE – Spanning Tree Bridge Group

•

These options can be used for DCI, but OTV was made for DCI

–

Optimizes ARP flooding over DCI

–

Demarc

of the STP domain

–

Can overlay multiple VLANs without complicated design

–

Allows multiple edge routers without complicated design

34Slide35

OTV Terms

• OTV Edge Device – Edge router(s) running OTV

• Authoritative Edge Device (AED)

–

Active edge router for a particular VLAN – Allows multiple redundant edge routers while preventing loops• Extend VLANs – VLAN being bridged over OTV• Site VLAN – Internal VLAN used to elect AED

35Slide36

OTV Terms Continued

• Site Identifier –

Unique ID per DC site, shared between AEDs

• Internal Interface

– Layer 2 interface where traffic to be encapsulated is received• Overlay Interface – The logical OTV tunnel interface that performs the OTVencapsulation• OTV Join Interface – The Layer 3 physical link or port-channel that you use to route upstream

towards the DCI

36Slide37

OTV Overview

37Slide38

OTV Control Plane

• Uses IS-IS to advertises MAC addresses between AEDs

– Is it’s own transport and extensible

• ISIS Encapsulated

as Control Group Multicast – IS-IS over Ethernet over MPLS over GRE over IPv4 Multicast – Implies that DCI must support ASM Multicast

38Slide39

OTV Data Plane

• Uses both Unicast and Multicast Transport

• Multicast Control Group

–

Multicast or Broadcast Control Plane Protocols – E.g. ARP, OSPF, EIGRP, etc.• Unicast Data – Normal Unicast is encapsulated as Unicast between AEDs• Multicast Data Group – Multicast Data flows are encapsulated as SSM Multicast – Implies AEDs use IGMPv3 for (S,G) Joins

39Slide40

OTV Adjacency Server

• Normally OTV requires that the DCI runs multicast

–

Needed to find and form IS-IS adjacencies and to tunnel

multicast data traffic• OTV Adjacency Server removes multicast requirement – One (or more) AEDs are configured as the adjacency server – All other AEDs register with the adjacency server – Now all endpoints are known• All control and data plane traffic is now unicast encapsulated

–

Will result in “Head End Replication” when more than 2

DC’s connected

over the DCI

40Slide41

OTV DCI Optimizations

• Other DCI options bridge all traffic over DCI – STP

, ARP,

L2 Flooding, broadcast

storms, etc.• OTV reduces unnecessary flooding by… – Proxy ARP/ICMPv6 Cache on AED – Terminating the STP domain on AED41Slide42

vPC Port Channels

–

Port Channels,

EtherChannels

, & NIC Teaming/Bonding terms used interchangeably– Regardless of vendor, 802.3ad (LACP) refers to Port Channeling• Used to aggregate bandwidth of multiple links between devices

– E.g. 4 x physical 1GigE links form a 4GigE logical Port Channel

•

Appears as one logical link from STP’s perspective

– Avoids active/standby and allows active/active

42Slide43

vPC Port Channels

• Data flows are load balanced between member links

–

Single flow cannot exceed BW of any physical member link

• E.g. increases lanes on the highway but not the speed limit• Does not perform LFI like PPP Multilink • Flows are load balanced based on L2, L3, & L4 headerinformation – SRC/DST VLAN, MAC, IP, & TCP/UDP Port• Default is SRC/DST L3 for IPv4/IPv6 and SRC/DST MAC

for non IP

–

Can result in over/under subscribed links

43Slide44

Port Channels

• Port Channeling was original between only 2 devices –

1 downstream device & 1 upstream device

• E.g. end host to Catalyst

3550 via 2 x FE links – Increases BW but still has single point of failure• Multi Chassis EtherChannel (MCEC/MEC) is between3 devices – 1 downstream device & 2 upstream devices

• E.g. end host to 2 x Catalyst 3750s via 2 x GigE links

–

Increases BW and resiliency

–

Logically appears the same as a 2 device Port Channel

44Slide45

Multi Chassis Ethernet Channels

• 3750 StackWise & 6500 VSS

single control plane

–

StackWise via Stacking Cable to connect BP – VSS via Virtual Switch Link (VSL)• vPC uses two separate control planes – Configurations managed independently

–

Separate control plane protocol instances

• STP, FHRPs, IGPs, BGP, etc.

–

Synchronization via a Peer Link

• Similar logic to VSS’s VSL

45Slide46

vPC Peer Switches

• vPC made up of 2 physical switches

–

The

vPC Peers• vPC Peers each have… – vPC Peer Link – vPC Peer Keepalive Link – vPC

Member Ports

46Slide47

vPC Overview

47Slide48

vPC Peer Link

• Layer 2 trunk link used to sync control plane

between

vPC

peers – CAM table, ARP cache, IGMP Snooping DB, etc. – Uses Cisco Fabric Service over Ethernet (CFSoE) protocol – Used to elect a vPC Primary and

vPC

Secondary Role

•

Normally not used for the data plane

–

Peer Link generally much lower BW than aggregate of

vPC

Member Ports

–

If Peer Link used in the data plane, it is the bottleneck

48Slide49

vPC Peer

Keepalive• Layer 3 link used as heartbeat in the control plane

–

Used to prevent active/active or “Split Brain”

vPC Roles – Not used in the vPC data plane – Uses unicast UDP port 3200• Peer Keepalive Link can be… – Mgmt0 port

•

Back to back or over routed infrastructure

• Ideally in an isolated VRF

49Slide50

vPC Member Ports

• Data plane port channel towards downstream neighbor

• Each

vPC

Peer has at least one member port per vPC – Can be more, up to hardware platform limits• From perspective of downstream neighbor, upstreamvPC Peers are one switch – Physical result is a triangle – Logical result is a point-to-point Port Channel with no

STP blocking

ports

50Slide51

vPC Order of Operations

• Enable feature

vpc

• Create a

vPC domain• Configure the vPC peer keepalive link• Create the vPC peer link• Move member ports to a vPC– Configurations must be consistent to avoid

Type 1 and

Type 2 errors

51Slide52

vPC Loop Prevention

• Goal of

vPC

is to hide redundant links from STP

– Could result in layer 2 flooding loops• Loops are prevented via “vPC Check” behavior – Frames received in the vPC Peer Link cannot flood out a vPC Member

Port while the remote

vPC

Peer has active

vPC

Members

in the same

vPC

•

vPC

Check Exception

–

If

vPC

Peer’s Member Ports are down, the

vPC

Member Ports become

“Orphan Ports” and the

vPC

Check

is disabled

–

vPC

Peer Link is essentially a last resort connection

52Slide53

vPC and FHRP

• Nexus 7000 is typically L2 & L3 network boundary

–

N7K is

vPC Peer but also end host’s FHRP Default Gateway• FHRP behavior changes to accommodate active/active forwardingover vPC – Traffic received in vPC Member Port of FHRP Standby to FHRPVirtual MAC is not forwarded over Peer Link to Active FHRP member –

Essentially HSRP Standby acts as HSRP Active

• FHRP

vPC

can break in certain non-standard vendor applications

–

Frames sent to FHRP Standby with physical DST MAC of FHRP

Active

are sent out the Peer Link

–

peer-gateway

allows

FHRP Standby to forward frames on

behalf of DST MAC of FHRP Active without going over Peer Link

53Slide54

vPC and Multicast

•

When source is reachable via

vPC

Member Port, both vPC Peers act as PIM DR – Called “Dual DR” or “Proxy DR”• Allows either vPC Primary or Secondary to receive

traffic from source and forward it

north without

having to cross the

vPC

Peer Link

–

Respects

vPC

check rule

54