CCIE Security Practice Labs

Section 2.0: Routing Configuration

2.1. OSPF

1. Configure OSPF as shown in Figure 5-3.

2. Configure simple authentication for all areas.

3. Tricky question for Area 3. The problem is you cannot configure Area 2 as a virtual link area.

4. The workaround is to configure a GRE tunnel between R3 and R5 and advertise it in Area 0. This way, you are extending Area 0 to R3, and Area 3 converges without configuring a virtual link.

5. This solution is very common when you have to address discontiguous Area 0s and you want to merge them:

   								! <snip from R5> interface Tunnel1 ip address 10.1.1.1 255.255.255.0 ip ospf authentication-key cisco tunnel source Serial1/1 tunnel destination 81.18.1.21 ! interface Serial1/0 ip address 173.5.1.129 255.255.255.128 encapsulation frame-relay ...