# Lab Topology

In this topology, there are four routers connected in a square shape. Each router has two loopback interfaces.

The 2001:db8:0:aa00::/56 network is available for you to allocate as you see fit.

## Lab Files

See general lab information to get started.

# Challenge – Scenario

No config has been pre-applied to this lab (other than hostnames).

You need to:

• Configure /127 links between each of the routers
• Configure two loopback interfaces on each router, with /64 networks
• Configure OSPFv3 on the four routers
• Make the loopback interfaces passive

## Challenge – Solution

Let’s start by allocating these networks to the routers:

• R1/R2 – 2001:db8:0:aa00::0 /127
• R2/R3 – 2001:db8:0:aa00::2 /127
• R3/R4 – 2001:db8:0:aa00::4 /127
• R4/R1 – 2001:db8:0:aa00::6 /127
```R1(config)#int gi0/0
R1(config-if)#no shut

R1(config)#int gi0/1
R1(config-if)#no shut
```
```R2(config)#int gi0/0
R2(config-if)#no shut

R2(config)#int gi0/1
R2(config-if)#no shut```
```R3(config)#int gi0/0
R3(config-if)#no shut

R3(config)#int gi0/1
R3(config-if)#no shut```
```R4(config)#int gi0/0
R4(config-if)#no shut

R4(config)#int gi0/1
R4(config-if)#no shut```

### Loopback Interfaces

We should now allocate /64’s for each loopback interface:

• R1, lo1 – 2001:db8:0:aa11:: /64
• R1, lo2 – 2001:db8:0:aa12:: /64
• R2, lo1 – 2001:db8:0:aa21:: /64
• R2, lo2 – 2001:db8:0:aa22:: /64
• R3, lo1 – 2001:db8:0:aa31:: /64
• R3, lo2 – 2001:db8:0:aa32:: /64
• R4, lo1 – 2001:db8:0:aa41:: /64
• R4, lo2 – 2001:db8:0:aa42:: /64
```R1(config)#int lo1

R1(config)#int lo2
```R2(config)#int lo1

R2(config)#int lo2
```R3(config)#int lo1

R3(config)#int lo2
```R4(config)#int lo1

R4(config)#int lo2

### OSPFv3

To configure OSPFv3, we start by enabling the process. This is the same on all routers. While we’re doing that, we can also set the reference bandwidth, as well as enabling passive interfaces by default (with gi0/0 and gi0/1 as non-passive).

```R1(config)#ipv6 unicast-routing
R1(config)#router ospfv3 10
R1(config-router)#auto-cost reference-bandwidth 1000000
R1(config-router)#passive-interface default
R1(config-router)#no passive-interface gi0/0
R1(config-router)#no passive-interface gi0/1
```

We should also set a router-ID as a matter of best practice:

```R1(config-router)#router-id 1.1.1.1

R2(config-router)#router-id 2.2.2.2

R3(config-router)#router-id 3.3.3.3

R4(config-router)#router-id 4.4.4.4```

Now to enable OSPF on interfaces. This can be repeated on all routers:

```R1(config)#int gi0/0
R1(config-if)#ipv6 ospf 10 area 0
% OSPFv3-10-IPv6:  Reference bandwidth is changed.
Please ensure reference bandwidth is consistent across all routers.

R1(config)#int gi0/1
R1(config-if)#ipv6 ospf 10 area 0

R1(config)#int lo1
R1(config-if)#ipv6 ospf 10 area 0

R1(config)#int lo2
R1(config-if)#ipv6 ospf 10 area 0```

One way to confirm this is working is to look at neighbours:

```R1#show ospf neighbor

OSPFv3 10 address-family ipv6 (router-id 1.1.1.1)

Neighbor ID     Pri   State           Dead Time   Interface ID    Interface
4.4.4.4           1   FULL/BDR        00:00:33    3               GigabitEthernet0/1
2.2.2.2           1   FULL/BDR        00:00:39    2               GigabitEthernet0/0```

The other way is to look at the routing table, and confirm all routes are there:

```R1#show ipv6 route
IPv6 Routing Table - default - 16 entries

C   2001:DB8:0:AA00::/127 [0/0]
via GigabitEthernet0/0, directly connected
L   2001:DB8:0:AA00::1/128 [0/0]
O   2001:DB8:0:AA00::2/127 [110/2000]
via FE80::5054:FF:FE03:687E, GigabitEthernet0/0
O   2001:DB8:0:AA00::4/127 [110/2000]
via FE80::5054:FF:FE02:6B4C, GigabitEthernet0/1
C   2001:DB8:0:AA00::6/127 [0/0]
via GigabitEthernet0/1, directly connected
L   2001:DB8:0:AA00::7/128 [0/0]
C   2001:DB8:0:AA11::/64 [0/0]
via Loopback1, directly connected
L   2001:DB8:0:AA11::1/128 [0/0]
C   2001:DB8:0:AA12::/64 [0/0]
via Loopback2, directly connected
L   2001:DB8:0:AA12::1/128 [0/0]
O   2001:DB8:0:AA21::1/128 [110/1000]
via FE80::5054:FF:FE03:687E, GigabitEthernet0/0
O   2001:DB8:0:AA22::1/128 [110/1000]
via FE80::5054:FF:FE03:687E, GigabitEthernet0/0
O   2001:DB8:0:AA31::1/128 [110/2000]
via FE80::5054:FF:FE03:687E, GigabitEthernet0/0
via FE80::5054:FF:FE02:6B4C, GigabitEthernet0/1
O   2001:DB8:0:AA32::1/128 [110/2000]
via FE80::5054:FF:FE03:687E, GigabitEthernet0/0
via FE80::5054:FF:FE02:6B4C, GigabitEthernet0/1
O   2001:DB8:0:AA41::1/128 [110/1000]
via FE80::5054:FF:FE02:6B4C, GigabitEthernet0/1
L   FF00::/8 [0/0]