Month: August 2018

[DC] Cloud Computing

Basic cloud computing

  • Essential Characteristics
    • Broad network access
    • Rapid elasticity
    • Measured Service
    • On-demand Self-service
    • Resource pooling
  • Service Models
    • SaaS – Software as a Service
    • PaaS – Platform as a Service
    • IaaS – Infrastructure as a Service
  • Deployment Models
    • Public
      • Provisitioned for open use by the general public
    • Private
      • Cloud for the exclusive use by a single organization
      • Managed by IT or thirdparty
      • on-premise or off-premise
    • Hybrid
      • Two or more cloud infrastructures combined
    • Community
      • Multiple organisations combined

What is an API

  • A precise specification written by providers of a service
  • You must follow the specification when using that service
  • An API decribes what functionality is available, how ti must be used and what formats it will accept as input or return as output

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[DC] ACI and APIC

ACI > Contructs

Tenant VDC
Context VRF
Bridge domain Subnet / SVI
EPG Broadcast domain / VLAN
Contract ACL
L2 External EPG 802.1Q trunk
L3 External EPG L3 Routed link

Fundamentals:

  • Open and Secure
  • Apps and Infrastructure
  • Physical and Virtual
  • On-Site and Cloud

Bringing up the Fabric:

  • Physical requirements
    • Power
    • Cabling + mgmt0
    • Rack and Stack
  • Power on/Connect to APICs
    • How many APICs
    • Fabric Name
    • Admin Password
    • Setup Fabric Network ( IP & VLAN)
  • Log into the APIC (HTTP out of band)
    • NTP
    • Route Reflectors
    • MGMT IP Fabric
    • Leaf and Spine Name/#

Fabric Discovery

  • Zero touch fabric, the controller does everything
  • APIC uses LLDP to get information about the leaf switches it’s connected to
  • First the leaf is dicovered and will be named (101)
  • Then the Spine is connected and named  (201)
  • Then the leafs are discovered (103,104)

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[DC] Datacenter Interconnects (DCI, OTV)

Distributed Data center Goals

  • Ensure business continuity
  • Distributed applications
  • Seamless workload mobility
  • Maximize compute resources

Challenges in traditional Layer 2 VPN:

  • Flooding Behavior
    • Unknown unicast for mac propagation
    • Unicast Flooding reaches all sites
  • Pseudo-wire Maintenance
    • Full mesh of Pseudo-wire is complex
    • Head-End replication is a common problem
  • Multi-Homing
    • Requires additional protocols and extends STP
    • Malfunctions impact multipe sites

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[DC] Nexus features config / commands

VDC Configuration

  • Show license usage
  • Show vdc
  • Show vdc membership
  • vdc DCC01
  • allocate resource command
  • limit-resource command
  • show run vdc
  • switchto vdc DCC01

FEX Configuration

  • Enable feature FEX
  • configure fex 100
  • interface e1/25
  • switchport mode fex-fabric
  • fex associate 100
  • show fex

VPC Configuration

  • feature vpc
  • vpc domain 100
  • peer-keepalive destination 10.10.10.2 source 10.10.10.1 vrf management
  • sh vpc
  • int po10
    • vpc peer-link
  • int e 1/25
    • channel-group 10 mode active
  • int po10
    • vpc 10

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