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Configure Campus Fabric Core-Distribution

Juniper Networks campus fabrics provide a single, standards-based EVPN-VXLAN solution that you can deploy on any campus. The campus fabric core-distribution solution extends the EVPN fabric to connect VLANs across multiple buildings. This network architecture includes the core and distribution layers that integrate with the access switching layer through the standard LACP.

For more background information about campus fabric core-distribution architectures, see the following documents:

To configure campus fabric core-distribution:

  1. Click Organization > Campus Fabric.
  2. If you want to create the campus fabric for a site, select the site from the drop-down list beside the page header. If you want to create the campus fabric for the entire organization, select Entire Org from the drop-down list.

    You can use an organization-level campus fabric topology to build a campus-wide architecture with multiple buildings. Otherwise, build a site-specific campus fabric with a single set of core, distribution, and access switches.

  3. Click whichever option is relevant. Click the:
    • Configure Campus Fabric button (displayed if the site doesn't have a campus fabric configuration associated with it).

    • Create Campus Fabric button (displayed if the site already has at least one campus fabric configuration associated with it).

    The Topology tab is displayed.
  4. Select the topology type Campus Fabric Core-Distribution.
  5. Configure the topology name and other settings on the Topology tab, as described below:
    Note:

    We recommend that you use the default settings on this screen unless they conflict with any networks attached to the campus fabric. The point-to-point links between each layer utilize /31 addressing to conserve addresses.

    1. In the CONFIGURATION section, enter the following:
      • Topology Name—Enter a name for the topology.

      • Topology Sub-type—Choose one of the following options:

        • CRB—In this model, the Layer 3 (L3) VXLAN gateway function is configured only on the core devices. This is accomplished by defining integrated routing and bridging (IRB) interfaces on the core devices to provide L3 routing services. This option uses virtual gateway addressing for all devices participating in the L3 subnet. Enabling this option configures core switches with a shared IP address for each L3 subnet. This address is shared between both the core switches and is used as the default gateway address for all devices within the VLAN. In addition, Mist assigns each core device with a unique IP address.

          • Virtual Gateway v4 MAC Address—Available only if you have selected CRB. If you enable it, Mist provides a unique MAC address to each L3 IRB interface (per network).

        • ERB—In this model, the L2 and L3 VXLAN gateway functions are configured on the distribution devices. In this case the IRB interfaces are defined on the distribution devices to provide L3 routing services. This option uses anycast addressing for all devices participating in the L3 subnet. In this case, the distribution switches are configured with the same IP address for each L3 subnet.

    2. (If you choose not to use the default settings) In the TOPOLOGY SETTINGS section, enter the following:
      • BGP Local AS—Represents the starting point of private BGP AS numbers that Mist allocates to each device automatically. You can use any private BGP AS number range that suits your deployment. Mist provisions the routing policy to ensure that the AS numbers are never advertised outside the fabric.

      • Subnet— The range of IP addresses that Mist uses for point-to-point links between devices. You can use a range that suits your deployment. Mist breaks this subnet into /31 subnet addressing per link. You can modify this number to suit the specific deployment scale. For example, a /24 network would provide up to 128 point-to-point /31 subnets.

      • Auto Router ID Subnet—Mist uses this subnet to automatically assign a router ID to each device in the fabric (including access devices irrespective of whether they are configured with EVPN or not). Router IDs are loopback interfaces (lo0.0) used for overlay peering between devices. For new topologies, this field auto-populates a default subnet value (172.16.254.0/23), which you can modify. When you edit an existing topology, this field doesn’t populate any default value. The router ID is used as an identifier when deploying routing protocols such as BGP.

        You can overwrite the automatically assigned router ID by manually configuring a loopback interface in the Router ID field on the Routing tile on the switch configuration page (Switches > Switch Name). However, if you modify the campus fabric configuration afterwards, Mist performs the automatic assignment of the router ID again, replacing the manually configured loopback interface.

      • Loopback per-VRF subnet—Mist uses this subnet to automatically configure loopback interfaces (lo0.x) per the virtual routing and forwarding (VRF) instance that is used for services such as DHCP relay. For new topologies, this field auto-populates a default subnet value (172.16.192.0/24), which you can modify. This field supports a /19 or smaller subnet (for example, /24). When you edit an existing topology, this field doesn’t populate any default value.

  6. Click Continue to go to the Nodes tab, where you can select devices that form part of the campus fabric deployment.
  7. Add switches to the Core, Distribution, and Access layer sections.

    To add switches:

    1. Click Select Switches in the section to which you want to add switches.
    2. Choose the switches that you want to add to the campus fabric.
    3. Click Select.

    We recommend that you validate the presence of each device in the switch inventory before creating the campus fabric.

    By default, Mist configures the core switches to function as border nodes that run the service block functionality. In a campus fabric topology, border nodes interconnect external devices such as firewalls, routers, or critical devices. External services or devices (for example, DHCP and RADIUS servers) connect to the campus fabric through border nodes. If you want to offload this task from the core switches and use dedicated switches as border nodes, clear the Use Core as border checkbox on the upper left of the page. You can then add up to two switches as dedicated border nodes.

    Also, Mist provides pods for improved scalability. Your access and distribution devices are grouped into pods. A pod could represent a building. For example, you can create a pod for each of the buildings in your site and create connections between the access and the distribution devices in that pod. You do not have to connect the same set of access devices to the distribution devices across multiple buildings. You can create multiple pods by clicking +Add Nodes.

  8. After selecting the switches, click Continue to go to the Network Settings tab, where you can configure the networks.
  9. Configure the network settings, as described below:
    1. On the NETWORKS tile, add networks or VLANs to the configuration. You can either create a new network or import the network from the switch template defined on the Organization > Switch templates page.

      To add a new VLAN, click Create New Network and configure the VLANs. The settings include a name, VLAN ID, and a subnet.

      To import VLANs from the template:

      1. Click Add Existing Network.

      2. Select a switch template from the Template drop-down list to view the VLANs available in that template.

      3. Select the required VLAN from the displayed list, and click the ✓ mark.

      VLANs are mapped to Virtual Network Identifiers (VNIs). You can optionally map the VLANs to VRF instances to logically separate the traffic.

    2. Review the settings on the OTHER IP CONFIGURATION tile, which populates the information automatically after you specify the networks in the NETWORKS section.

      Mist provides automatic IP addressing of IRBs for each of the VLANs. Then, the port profile associates the VLAN with the specified ports.

    3. Optionally, configure VRF instances on the VRF tile. By default, Mist places all VLANs in the default VRF. The VRF option allows you to group common VLANs into the same VRF or separate VRFs depending on traffic isolation requirements. All VLANs within each VRF have full connectivity with each other and with other external networking resources. A common use case is the isolation of guest wireless traffic from most enterprise domains, except Internet connectivity. By default, a campus fabric provides complete isolation between VRFs, forcing inter-VRF communications to traverse a firewall. If you require inter-VRF communication, you need to include extra routes to the VRF. The extra route could be a default route that instructs the campus fabric to use an external router. It could also be a firewall for further security inspection or routing capabilities.

      To create a VRF:

      1. Click Add VRF Instance and specify the settings. The settings include a name for the VRF and the networks to be associated with the VRF.

      2. To add extra routes, click the Add Extra Routes link on the New VRF Instance page and specify the route.

    4. On the DISTRIBUTION / ACCESS PORT CONFIGURATION tile, complete the port configuration for ESI-LAG between the collapsed core and access switches. The settings include a name and other port configuration elements. By default, this configuration includes the networks added on the NETWORKS tile on the same page. If you want to remove or modify the settings, click Show Advanced and configure the settings. Use the tips on the screen to configure the port profile settings.
  10. Click Continue to go to the Ports tab, where you can configure the ports and create a connection between the core, distribution, and access layer switches.
  11. Configure the switch ports in the core layer as described below:
    1. Select a switch in the Core section to open the switch port panel.
    2. From the port panel of the core switch, select a port that you want to configure.
    3. Specify a port type (for example, ge or xe).
    4. Choose the distribution switch on which the link should terminate. You need to configure all the ports that need to be part of the campus fabric.

    To configure switch ports in the distribution layer:

    1. Select a switch in the Distribution section to open the switch port panel.
    2. From the port panel of the switch, select a port that you want to configure.
    3. Specify a port type (for example, ge or xe).
    4. Select:
      • Link to Core to connect the port to a core switch.

      • Link to Access to connect the port to an access switch.

    5. Select the core or access switch (based on the selection in the previous step) on which the link should terminate. You need to configure all the ports that need to be part of the campus fabric.
    To configure the switch ports in the access layer:
    1. Select a switch in the Access section to open the switch port panel.
    2. From the port panel of the switch, select a port that you want to configure.
    3. Specify a port type (for example, ge or xe).
      In case the access layer uses a Virtual Chassis (VC), you can configure ports on the Primary and Backup tabs.

    For the access switches, select only those interfaces that should be used to interconnect with the distribution switch. The system bundles all interfaces into a single Ethernet bundle through the AE index option. You can specify an AE index value for the access devices.

    If you want to view the configuration and status information of a specific port, hover over the numbered box representing that port in the port panel UI.

  12. Click Continue to go to the Confirmation tab.
  13. Click each switch icon to view and verify the configuration.
  14. After verifying the configuration, click Apply Changes > Confirm.
    This step saves the campus fabric configuration to the Mist cloud and applies it to the switches. If the switches are offline, the configuration will be applied to them when they come online next time. A switch might take up to 10 minutes to complete the configuration.
  15. Click Close Campus Fabric Configuration.

    After Mist builds the campus fabric, or while it is building the fabric, you can download the connection table. The connection table represents the physical layout of the campus fabric. You can use this table to validate all switch interconnects for the devices participating in the physical campus fabric build. Click Connection Table to download it (.csv format).

  16. Verify the campus fabric configuration. To verify, follow the steps listed in the Verification section of Campus Fabric Core Distribution CRB (JVD) and Campus Fabric Core-Distribution ERB (JVD).

For a demo, watch the following video:

Video: Deployment of Campus Fabric Core-Distribution