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Design

 

Explanation of Procedure

In the design stage, you use progressively larger building blocks to construct your network. You start by defining the devices, then the racks that hold these devices, and finally the templates that describe how these racks are connected together. The template definition is very flexible. A template represents a standalone part in your data center such as a row of racks, a pod, or the entire data center network. In this use case, the template represents your entire data center network.

A template is not specific to a site. It does not contain site-specific details such as IP addresses or other resource pools, nor does it contain any hardware-specific information. The idea is that you can use this same template to create blueprints for all your data center locations regardless of what IP addresses and physical equipment you use at the different locations.

Define the Logical Devices

Create the logical devices that represent the leaf and spine switches and servers. Logical devices are abstractions of physical devices. In effect, by creating logical devices, you’re specifying the minimum set of requirements for your hardware. At a later stage when you select the actual devices for your fabric, AOS will only allow you to select the physical switches and servers that meet these requirements.

With this approach, your data center design is not predicated on the deployment of any specific physical device. This reduces device dependency, facilitates equipment inventory management, and promotes design reuse. For example, if a particular device fails in your network, you don’t have to replace the failed device with the exact same model. You can replace it with a different model as long as the new model meets the specified requirements. All you have to do is tweak your blueprint to use that model. Your network design remains unchanged.

AOS ships with a predefined set of logical devices that you can use in many situations. In this use case, you’ll create your own logical devices for the leaf and spine switches, but you’ll use a predefined server (AOS-1x10-1).

Note

You’re creating logical device types and not logical device instances. In other words, if your data center has one type of leaf switch deployed across numerous racks, then you’re creating a single logical device representing that type of leaf switch. You’re not creating each instance of that leaf switch yet. You create instances when you define the rack and template.

  1. Select Design>Logical Devices to bring up the Logical Devices page.
  2. Create the logical device representing the leaf switch. In this use case, the leaf device has 2 x 10 Gbps ports connecting to servers, and 2 x 40 Gbps ports connecting to spine devices.
    1. Click Create Logical Device. The Create Logical Device window appears.
    2. Specify a meaningful Name for this logical device (for example, AOS-2x10+2x40).
    3. Configure the 2 x 10 Gbps ports on this device to connect to the servers.
      • PANEL #1 shows a 24-port pictogram. Drag the corner of the pictogram to form 2 ports. By default, the ports are set to 10 Gbps, which is what you want.

      • Specify that these ports connect to L2 servers by selecting L2 Server in the Connected To section.

      • Click Create Port Group.

    4. Configure the 2 x 40 Gbps ports on this device to connect to the spine devices.
      • Click Add Panel to add PANEL #2.

      • In PANEL #2, drag the corner of the 24-port pictogram to form 2 ports.

      • Use the drop-down list to set the Speed to 40 Gbps.

      • Specify that these ports connect to spine devices by selecting Spine in the Connected To section.

      • Click Create Port Group.

    5. Click Create.
  3. Create the logical device representing the spine switch. The spine device has 2 x 40 Gbps ports connecting to leaf devices.
    1. Click Create Logical Device. The Create Logical Device window appears.
    2. Specify a meaningful Name for this logical device (for example, AOS-2x40).
    3. Configure the 2 x 40 Gbps ports on this device to connect to the leaf devices.
      • In PANEL #1, drag the corner of the 24-port pictogram to form 2 ports.

      • Use the drop-down list to set the Speed to 40 Gbps.

      • Specify that these ports connect to leaf devices by selecting Leaf in the Connected To section.

      • Click Create Port Group.

    4. Click Create.
Note

At this stage, there is no correlation between the port numbers shown in the pictograms and the port numbers on the actual physical devices. All you’ve specified so far is that the leaf device has two 10 Gbps ports connecting to servers and two 40 Gbps ports connecting to spine devices, and that the spine device has two 40 Gbps ports connecting to the leaf devices.

Define Interface Maps

An interface map associates a physical device with a logical device and includes the mapping of ports from one to the other. In this part of the design process, you’re pairing the physical devices you want to deploy in your fabric with the logical devices in your design. You’re not actually selecting your physical devices in this step. You’re just creating a library of pairings that you’ll pick from later on.

If you have different candidates for the actual device hardware (for example, different QFX Series switch models that you want to use for your leaf devices), then you’ll create interface maps that pair each candidate with the logical device in your design. Later, when you build your blueprint, you’ll select the QFX Series switch model you want to deploy and then AOS will pick the corresponding interface map.

AOS ships with a predefined set of interface maps for the predefined set of logical devices. In many situations, you should be able to pick from this predefined list instead of creating your own. In this use case, however, since you’ve created your own logical devices, you’ll need to create your own interface maps for those devices. You’ll create one interface map for the spine device and one interface map for the leaf device.

  1. Select Design>Interface Maps to bring up the Interface Maps page.
  2. Create the interface map for the leaf device. The interface map you create in this step maps the physical leaf switch you want to use in your fabric (QFX5110-48S) to the logical device representing the leaf switch in your design (AOS-2x10+2x40).
    1. Click Create Interface Map. The Create Interface Map window appears.
    2. Specify a meaningful Name for this interface map (for example, Juniper_QFX5110-48S____AOS-2x10+2x40). This name clearly indicates the association between the physical device you want to use and the logical device in your design.
    3. Use the Logical device drop-down list to select the logical leaf device you created earlier (AOS-2x10+2x40).
    4. Use the Device profile drop-down list to select the model of the actual physical leaf switch (Juniper_QFX5110-48S). AOS only allows you to select device profiles that meet the logical device requirements. For example, if your logical device has two 40 Gbps ports, AOS only allows you to select device profiles that have at least two 40 Gbps ports.
    5. Specify which ports connect to the servers.

      In the 10 Gbps row in the Map interfaces table, click Select interfaces. A port pictogram representing the QFX5110-48S appears.

      Recall from Figure 1 that you’re using xe-0/0/0 and xe-0/0/1 to connect to the servers. Select port 1 and port 2 in the pictogram.

      Note

      AOS begins indexing interfaces at 1 while the QFX Series switches begin their numbering at 0. That’s why port 1 and port 2 map to xe-0/0/0 and xe-0/0/1 respectively.

    6. Specify which ports connect to the spine devices.

      In the 40 Gbps row in the Map interfaces table, click Select interfaces. A port pictogram representing the QFX5110-48S appears.

      Recall from Figure 1 that you’re using xe-0/0/48 and xe-0/0/50 to connect to the spine devices. Select port 49 and port 51, representing xe-0/0/48 and xe-0/0/50 respectively.

    7. Click Create.
  3. Create the interface map for the spine device. The interface map you are creating in this step maps the physical spine switch you want to use in your fabric (QFX10002-36Q) to the logical device representing the spine switch in your design (AOS-2x40).
    1. Click Create Interface Map. The Create Interface Map window appears.
    2. Specify a meaningful Name for this interface map (for example, Juniper_QFX10002-36Q____AOS-2x40).
    3. Use the Logical device drop-down list to select the logical leaf device you created earlier (AOS-2x40).
    4. Use the Device profile drop-down list to select the model of the actual physical leaf switch (Juniper_QFX10002-36Q).
    5. Specify which ports connect to the leaf devices.

      In the 40 Gbps row in the Map interfaces table, click Select interfaces. A port pictogram representing the QFX10002-36Q appears.

      Recall from Figure 1 that you’re using et-0/0/34 and et-0/0/35 to connect to the leaf devices. Select port 35 and port 36, representing et-0/0/34 and et-0/0/35 respectively.

    6. Click Create.

Define Racks

You’ve defined the first set of building blocks for your data center design, namely the logical devices that represent your hardware. You’re now ready to define the next building block, which is the rack that houses these logical devices.

A rack represents a physical rack in the data center. It consists of one or more Top-of-Rack (ToR) switches and a bank of servers.

AOS ships with a set of predefined racks that cover many common deployments, but these are too elaborate for this use case. In this use case, you’ll create a simple rack consisting of one leaf device and two servers.

Note

You’re creating rack types and not rack instances. In other words, if your data center has one type of rack deployed, then you’re creating a single rack type. You’re not creating each instance of that rack yet. You create instances when you define the template.

  1. Select Design>Rack Types to bring up the Rack Types page.
  2. Create the rack you’ll use in your design.

    1. Click Create Rack Type. The Create Rack Type window appears.
    2. Specify a meaningful name for the rack (for example, L2 1L2S).
    3. Specify a description for the rack (for example, Layer 2, one leaf switch and two servers).
    4. Set the Connectivity Type to L2, which means that the leaf switch connects to the servers using VLANs or VXLANs. This is the typical setting when connecting to bare metal servers.
  3. Configure the leaf device.

    The Configuration section contains 3 tabs: Leafs, Access Switches, and Servers.

    1. Select the Leafs tab.
    2. Fill in the required fields (Table 9).

      Table 9: Leaf Switch Configuration for the Rack

      Parameter

      Description

      Setting in this Use Case

      Name

      The name of this leaf switch.

      This is the name you want to give to the leaf switch in the design. This is not the hostname of any physical switch in your fabric. In the build stage, you will assign the actual physical switch to represent this leaf switch.

      1L2S-Leaf

      Leaf Logical Device

      The logical device that you want to use as the leaf switch.

      Based on this selection, AOS limits the selectable values in the remaining fields to what this logical device supports.

      AOS-2x10+2x40

      Links per spine

      The number of links connecting this leaf switch to any single spine switch.

      1

      Link speed

      The speed of the link connecting this leaf switch to any single spine switch.

      40 Gbps

  4. Configure the servers.

    1. In the Configuration section, select the Servers tab.
    2. Click Add new server group.
    3. Fill in the required fields (Table 10).

      Table 10: Server Configuration for the Rack

      Parameter

      Description

      Setting in this Use Case

      Name

      The name of the servers.

      This is the name you want to give to the servers in the design. This is not the hostname of any physical server.

      1L2S-Server

      Server count

      The number of servers in this rack.

      2

      Logical Device

      The logical device that you want to use as the server.

      Based on this selection, AOS limits the selectable values in the remaining fields to what this logical device supports.

      AOS-1x10-1

      Link (click Add link)

      Name

      The name of the link.

      1L2S-Leaf-to-Server

      Switch

      The leaf switch that this server connects to.

      If you’ve added only one leaf switch to this rack as in this use case, then AOS pre-populates this field with the name of that leaf switch.

      1L2S-Leaf

      Physical link count per leaf

      The number of links connecting this server to the leaf switch.

      1

      Link speed

      The speed of the link between this server and the leaf switch.

      10 Gbps

      Note: As you enter information, AOS draws a preview of the rack based on the information you enter. This allows you to better visualize the rack you’re creating.

    4. Click Create.

Define Templates

You’ve now created your logical devices and the racks that hold these logical devices. You’re now ready to define the next building block, which is the template that describes how the racks are connected together.

A template can represent a row or a pod in your data center. In this use case, the template represents the entire data center, which consists of two racks.

  1. Select Design>Templates to bring up the Templates page.
  2. Click Create Template. The Create Template window appears.
  3. Fill in the required fields (Table 11) and click Create.

    Table 11: Create Template

    Parameter

    Description

    Setting in this Use Case

    Common Parameters>Name

    The name you want to call this template.

    L2 Pod 2x2

    Common Parameters>Type

    RACK BASED for creating a set of racks (for a 3-stage Clos).

    POD BASED for creating a set of pods (for a 5-stage Clos).

    RACK BASED

    Policies>Overlay Control Protocol

    Static VXLAN for static tunnels.

    MP-EBGP EVPN for dynamic VXLAN tunnels.

    MP-EBGP EVPN

    Structure>Rack Types

    Select the rack type and the number of instances of that rack type from the drop-down lists. This use case consists of two instances of the same rack type.

    If your design has multiple different rack types, then simply click Add racks to add them.

    L2 1L2S

    2 instances

    Structure>Spines>Spine Logical Device

    Select the logical device for the spine from the drop-down list. The drop-down list shows all logical spine devices. If you select a logical spine device that is incompatible with your design, AOS will display an error when you try to create the template.

    AOS-2x40

    Structure>Spines>Count

    The number of spine switches.

    2

    Note: As you enter information, AOS draws a preview of the design based on the information you enter. This allows you to better visualize the template you’re creating. Click Expand Nodes and/or Show Links to show more detail as desired. See Figure 6.

     
    Figure 6: Template Preview
    Template Preview

    AOS automatically appends an instance number to the names of the devices as follows:

    • spines - AOS automatically names the spine device as spine and appends an instance value to represent the instances. The format is spine<instance> (for example, spine1).

    • racks - AOS appends a rack instance value to the rack type you specified. The format is <rack type> <instance> (for example, l2 1l2s 1).

    • leafs - AOS appends a leaf instance value to the name of the leaf device in this rack type. The format is <leaf name>_<instance> (for example, 1L2S-Leaf_1). The instance value represents the instance of the leaf device within the rack.

    • servers - AOS appends a server instance value to the name of the server in this rack type. The format is <server name>_<instance> (for example, 1L2S-Server_1). The instance value represents the instance of the server within the rack.

Your design is now complete! You’ve created the logical devices, the racks that hold these logical devices, and finally the template that describes how these racks are connected together. You’re now ready to enter the build phase.