Aruba CX - OSPF - Basics

Category: Networking

Skills: OSPF, Routing,

Equipment: Aruba CX Virtual Switches, Virtual PC's, Eve-Ng

Objective

Learn the basics of OSPF routing
Configure OSPF on 4 seperate Layer 3 switches

Topology

Devices

4 x Aruba CX Switches (Virutal)
4 x Virtual PCs

Steps

Setup your lab enviroment based on the topology above
Turn on all nodes
- If using EVEng (Click “More Actions” on the side and “Start all nodes”
You will need to confiugre each switch
- Hostname
- Interface IP
- Enable interfsces
Configure OSPF Routing
Test Pinging different PCs
Explorer useful commands

Configure Switches Hostname & Interface IP Addresses

sw1

switch(config)# hostname sw1

sw1(config)# int 1/1/1
sw1(config-if)# ip address 192.168.1.1/24

sw1(config-if)# int 1/1/2
sw1(config-if)# ip address 10.0.12.1/30

sw1(config-if)# int 1/1/3
sw1(config-if)# ip address 10.0.14.1/30

sw1(config-if)# int 1/1/1-1/1/3
sw1(config-if-<1/1/1-1/1/3>)# no shutdown

sw2

switch(config)# hostname sw2

sw2(config)# int 1/1/1
sw2(config-if)# ip address 192.168.2.1/24

sw2(config-if)# int 1/1/2
sw2(config-if)# ip address 10.0.12.2/30

sw2(config-if)# int 1/1/3
sw2(config-if)# ip address 10.0.23.1/30

sw2(config-if)# int 1/1/1-1/1/3
sw2(config-if-<1/1/1-1/1/3>)# no shutdown

sw3

switch(config)# hostname sw3

sw3(config)# int 1/1/1
sw3(config-if)# ip address 192.168.3.1/24

sw3(config-if)# int 1/1/2
sw3(config-if)# ip address 10.0.43.2/30

sw3(config-if)# int 1/1/3
sw3(config-if)# ip address 10.0.23.2/30

sw3(config-if)# int 1/1/1-1/1/3
sw3(config-if-<1/1/1-1/1/3>)# no shutdown

sw4

switch(config)# hostname sw3

sw4(config)# int 1/1/1
sw4(config-if)# ip address 192.168.4.1/24

sw4(config-if)# int 1/1/2
sw4(config-if)# ip address 10.0.43.1/30

sw4(config-if)# int 1/1/3
sw4(config-if)# ip address 10.0.14.2/30

sw4(config-if)# int 1/1/1-1/1/3
sw4(config-if-<1/1/1-1/1/3>)# no shutdown

Configure Virtual PCs Hostname & Interface IP Addresses

vpc1

VPCS> set pcname vpc1

vpc1> ip 192.168.1.2/24 192.168.1.1
         IP ADDRESS     DEFAULT GATEWAY

vpc2

VPCS> set pcname vpc2

vpc2> ip 192.168.2.2/24 192.168.2.1
         IP ADDRESS     DEFAULT GATEWAY

vpc3

VPCS> set pcname vpc3

vpc3> ip 192.168.3.2/24 192.168.3.1
         IP ADDRESS     DEFAULT GATEWAY

vpc4

VPCS> set pcname vpc4

vpc4> ip 192.168.4.2/24 192.168.4.1
         IP ADDRESS     DEFAULT GATEWAY

Configure OSPF

We will set the OSPF proccess id as 1
We will set the Router-ID to the following (this can be anything it is not an IP address)
- sw1 = 1.1.1.1
- sw2 = 2.2.2.2
- sw3 = 3.3.3.3
- sw4 = 4.4.4.4
we will setup area 0 (This is the backbone)

sw1

sw1(config-ospf-1)# router ospf 1
sw1(config-ospf-1)# router-id 1.1.1.1

sw1(config-ospf-1)# int 1/1/1-1/1/3
sw1(config-if-<1/1/1-1/1/3>)# ip ospf 1 area 0
OSPF Area is not configured.
Do you want to create (y/n)? y

sw2

sw2(config)# router ospf 1
sw2(config-ospf-1)# router-id 2.2.2.2

sw2(config-ospf-1)# int 1/1/1-1/1/3
sw2(config-if-<1/1/1-1/1/3>)# ip ospf 1 area 0
OSPF Area is not configured.
Do you want to create (y/n)? y

sw3

sw3(config)# router ospf 1
sw3(config-ospf-1)# router-id 3.3.3.3

sw3(config-ospf-1)# int 1/1/1-1/1/3
sw3(config-if-<1/1/1-1/1/3>)# ip ospf 1 area 0
OSPF Area is not configured.
Do you want to create (y/n)? y

sw4

sw4(config)# router ospf 1
sw4(config-ospf-1)# router-id 4.4.4.4

sw4(config-ospf-1)# int 1/1/1-1/1/3
sw4(config-if-<1/1/1-1/1/3>)# ip ospf 1 area 0
OSPF Area is not configured.
Do you want to create (y/n)? y

Activities

From vp1 ping vpc3 (192.168.3.2)
- Was it sucessful?
use the command sh ip route You should see several routes
- Routes with orgin/Type is OSPF routes

Anoher good command is sh ip ospf neighbors

Here you will see DR and BDR
- DR = Designated Router
  - Acts as the hub for LSAs on that network
  - Chosen by highest priority (default is 1, 0-255)
- BDR = Backup Designated Router
  - Takes over if the DR goes down

Common Commands for OSPF

router ospf <process id>
router-id <0.0.0.0>
ip ospf <process id> area <area number - Usually 0>
sh ip routed
sh ip ospf neighbors
sh ip ospf interface
sh interface brief Less common for ospf

Common issues

Wrong subnet mask at one end
Duplicate IP on a segment
Wrong netowrk at one end of a segment