ArubaOS-CX, OSPFv2 Configuration

OSPF configuration is simple on Aruba, with a few simple differences between OS-CX and Cisco’s approach. Once both configured though, the two vendors equipment works very well, just as expected.

For clarity, to confirm the current OSPF state we can check to see if it is running. I’ve checked both the Default VRF and the FWTEST VRF whose configuration is explained here.

ArubaOS-CX# sh ip ospf
OSPF Process is not running on VRF default.
ArubaOS-CX# sh ip ospf vrf FWTEST
OSPF Process is not running on VRF FWTEST.

Initially in this example we will configure OSPFv2 to run in the FWTEST VRF, whilst leaving the Default VRF as it is. To start the process, we need to define OSPF

ArubaOS-CX# conf t
ArubaOS-CX(config)# router ospf 
  <1-63>  Specify the OSPF Process ID 
ArubaOS-CX(config)# router ospf 39 
  vrf   VRF Instance. 
ArubaOS-CX(config)# router ospf 39 vrf FWTEST
ArubaOS-CX(config-ospf-39)# router ospf 39 vrf FWTEST

Much like the Cisco CLI, you can use the ? to show command help as appropriate. Here for example, we can see that Aruba use 6-bits to store the process ID. The process ID is only locally significant and good practise would be to use different process ID’s for each VRF. In testing though ArubaOS-CX does appear to allow you to use the same number for default and another VRF. I was surprised that it didn’t seem to break anything, but going forward I will use separate IDs. Here I chose 39 and specified which VRF it applied to.

We then go on to specify a router-id and other operating behaviours we need.

ArubaOS-CX(config-ospf-39)# router-id
ArubaOS-CX(config-ospf-39)# reference-bandwidth 40000
ArubaOS-CX(config-ospf-39)# passive-interface default
ArubaOS-CX(config-ospf-39)# redistribute connected
ArubaOS-CX(config-ospf-39)# area

At this stage, we do not have any ospf interfaces attached to the vhf FWTEST.

ArubaOS-CX# sh ip ospf vrf FWTEST
Routing Process 39 with ID : VRF FWTEST

OSPFv2 Protocol is enabled
Graceful-restart is configured
Restart Interval: 120, State: inactive
Last Graceful Restart Exit Status: none
SPF: Start Time: 200ms, Hold Time: 1000ms, Max Wait Time: 5000ms
Maximum Paths to Destination: 4
Number of external LSAs 0, checksum sum 0
Number of areas is 1, 1 normal, 0 stub, 0 NSSA
Number of active areas is 0, 0 normal, 0 stub, 0 NSSA
BFD is disabled
Reference Bandwidth: 40000 Mbps
Area ( (Inactive)
  Interfaces in this Area: 0 Active Interfaces: 0 
  Passive Interfaces: 0 Loopback Interfaces: 0 
  SPF calculation has run 1 times
  Area ranges: 
  Number of LSAs: 0, checksum sum 0 

ArubaOS-CX# sh ip ospf interface vrf FWTEST
OSPF Interface is not attached to VRF FWTEST.

So next we need to attach at least one interface, the area were are attaching to is already defined above, if it isn’t defined you will get an error.

ArubaOS-CX# conf t
ArubaOS-CX(config)# interface vlan999 
           config-if-vlan)# ip ospf 39 area                         
ArubaOS-CX(config-if-vlan)# no ip ospf passive              

For a basic configuration that the config that’s required. We are not running VRF-lite, with a Cisco 4500 as a neighbour. We can see from our routing table all is well.

ArubaOS-CX# sh ip ro vrf FWTEST

Displaying ipv4 routes selected for forwarding

'[x/y]' denotes [distance/metric], vrf FWTEST 
        via,  [110/114],  ospf, vrf FWTEST 
        via  vlan998,  [0/0],  connected, vrf FWTEST 
        via  loopback99,  [0/0],  connected, vrf FWTEST 
        via  vlan999,  [0/0],  connected, vrf FWTEST 
        via,  [110/64],  ospf, vrf FWTEST 
        via,  [110/44],  ospf, vrf FWTEST 
        via,  [110/54],  ospf, vrf FWTEST 
        via,  [110/84],  ospf, vrf FWTEST 
        via  vlan999,  [0/0],  local, vrf FWTEST 
        via  loopback99,  [0/0],  local, vrf FWTEST 
        via  vlan998,  [0/0],  local


As you would expect for a standards based protocol, it just works !

Finally just for reference, this was all done on an 6300 running AribaOS-CX FL.10.04.0030