Design Reference

The routers in example 2 use the following configuration:
• S1 has an OSPF router ID of 1.1.1.1, and the OSPF port uses an IP address of 192.168.10.1.
• S2 has an OSPF router ID of 1.1.1.2, and two OSPF ports use IP addresses of 192.168.10.2
and 192.168.20.1.
• S3 has an OSPF router ID of 1.1.1.3, and the OSPF port uses an IP address of 192.168.20.2.
The general method to configure OSPF on each routing switch is:
1. Enable OSPF globally.
2. Insert IP addresses, subnet masks, and VLAN IDs for the OSPF ports on S1 and S3, and for
the two OSPF ports on S2. The two ports on S2 enable routing and establish the IP
addresses related to the two networks.
3. Enable OSPF for each OSPF port allocated with an IP address.
After you configure all three switches for OSPF, they elect a designated router and a backup
designated router for each subnet and exchange hello packets to synchronize their link-state
databases.
The following figure shows an example where OSPF operates on two subnets in two OSPF areas.
S2 becomes the area border router for both networks.
Figure 24: Example 3: OSPF on two subnets in two areas
The routers in scenario 3 use the following configuration:
• S1 has an OSPF router ID of 1.1.1.1. The OSPF port uses an IP address of 192.168.10.1,
which is in OSPF area 1.
• S2 has an OSPF router ID of 1.1.1.2. One port uses an IP address of 192.168.10.2, which is in
OSPF area 1. The second OSPF port on S2 uses an IP address of 192.168.20.1, which is in
OSPF area 2.
• S3 has an OSPF router ID of 1.1.1.3. The OSPF port uses an IP address of 192.168.20.2,
which is in OSPF area 2.
The general method to configure OSPF for this three-switch network is:
1. On all three switches, enable OSPF globally.
Layer 3 network design
64 Network Design Reference for Avaya VSP 4000 Series December 2014
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