Configuring an IP Address and OSPF on the Backbone VLAN

  1. Configure an IP address and enable IP forwarding (routing) on the backbone protected VLAN.
  2. OSPF is configured and because an OSPF broadcast network is used, configure the designated router and backup designated router for each VLAN.

    Since it is not performing L2 blocking, configure the EAPS transit core switch as the DR by using a higher OSPF priority value. The EAPS master core switch is configured as the BDR. The aggregation transit switches need not perform DR/BDR duties for the backbone VLAN, so their OSPF priority is configured at 0 to force ODR behavior.

    Core-Switch#1 OSPF configuration:

    * CORE-SWITCH#1.12 # configure vlan backbone ipaddress 192.168.1.1/24
    * CORE-SWITCH#1.13 # enable ipforwarding vlan backbone
    * CORE-SWITCH#1.14 # configure ospf routerid 192.168.1.1
    * CORE-SWITCH#1.15 # configure ospf add vlan backbone area 0.0.0.0
    * CORE-SWITCH#1.16 # configure ospf vlan backbone priority 110
    * CORE-SWITCH#1.17 # enable ospf

    Core-Switch#2 OSPF configuration:

    * CORE-SWITCH#2.12 # configure vlan backbone ipaddress 192.168.1.2/24
    * CORE-SWITCH#2.13 # enable ipforwarding vlan backbone
    * CORE-SWITCH#2.14 # configure ospf routerid 192.168.1.2
    * CORE-SWITCH#2.15 # configure ospf add vlan backbone area 0.0.0.0
    * CORE-SWITCH#2.16 # configure ospf vlan backbone priority 100
    * CORE-SWITCH#2.17 # enable ospf

    Agg-Switch#1 OSPF configuration:

    * AGG-SWITCH#1.11 # configure vlan backbone ipaddress 192.168.1.3/24
    * AGG-SWITCH#1.12 # enable ipforwarding vlan backbone
    * AGG-SWITCH#1.13 # configure ospf add vlan backbone area 0.0.0.0
    * AGG-SWITCH#1.14 # configure ospf vlan backbone priority 0

    Agg-Switch#2 OSPF configuration:

    * AGG-SWITCH#2.11 # configure vlan backbone ipaddress 192.168.1.4/24
    * AGG-SWITCH#2.12 # enable ipforwarding vlan backbone
    * AGG-SWITCH#2.13 # configure ospf add vlan backbone area 0.0.0.0
    * AGG-SWITCH#2.14 # configure ospf vlan backbone priority 0