FREE CCNP LAB

In this Free CCNP GNS3 Lab we are going to use GNS3 to create simple BGP network consisting of four Cisco routers and a single switch to demonstrate how we can use BGP’s weight attribute to influence routing out of an autonomous system (AS).

The BGP Weight attribute is a Cisco Proprietary attribute that influences a router how to reach a certain prefix. The difference between Local Preference and Weight is that the former is propagated within an AS and the latter is router locally significant. Weight can be used if there is one router connected to two or more AS’s or just to just one with two or more eBGP peers.

Learning Objectives:

• Configure basic BGP routing.
• Understand Cisco’s weight attribute.
• Configure prefix-list.
• Configure route-map.
• Apply route-map to BGP neighbor.

Lab Tasks:

Basic Configuration:

1. Configure IP addresses and subnet mask on Loopback interfaces of all routers as shown in the network diagram.
2. Configure IP addresses and subnet mask on Fastethernet interfaces of all routers as shown in the network diagram.
3. Configure IP addresses and subnet mask on Serial interfaces of all routers as shown in the network diagram.
4. Insure that all Fastethernet and serial interfaces are not administrative down.

OSPF Configuration:

1. Enable the OSPF routing protocol as process 100 on R3 and R4.
2. Configure Loopback interfaces of R3 and R4 to be passive.
3. Configure network 3.3.3.3/32 to be part of the OSPF routing protocol in OSPF area 0 on R3.
4. Configure network 10.200.34.0/30 to be part of the OSPF routing protocol in OSPF area 0 on R3.
5. Configure network 192.168.3.0/24 to be part of the OSPF routing protocol in OSPF area 0 on R3.
6. Configure network 4.4.4.4/32 to be part of the OSPF routing protocol in OSPF area 0 on R4.
7. Configure network 10.200.34.0/30 to be part of the OSPF routing protocol in OSPF area 0 on R4.
8. Configure network 192.168.4.0/24 to be part of the OSPF routing protocol in OSPF area 0 on R4.
9. Configure Loopback interfaces Lo1 of R3 and R4 as OSPF point-to-point networks.
10. Verify OSPF configuration.

BGP Configuration:

1. Enable BGP routing protocol on R1 as autonomous system 65101.
2. Configure R2 and R3 as BGP neighbors.
3. Advertise the 172.16.1.0 network.
4. Enable BGP routing protocol on R2 as autonomous system 65102.
5. Configure R1 and R4 as BGP neighbors.
6. Enable BGP routing protocol on R3 as autonomous system 65134.
7. Configure R1 and R4 as BGP neighbors.
8. Configure Loopback interface Lo0 as the BGP update source.
9. Configure the next hop as self.
10. Advertise the 192.168.3.0 network.
11. Enable BGP routing protocol on R4 as autonomous system 65134.
12. Configure R2 and R3 as BGP neighbors.
13. Configure Loopback interface Lo0 as the BGP update source.
14. Configure the next hop as self.
15. Advertise the 192.168.4.0 network.
16. Verify BGP configuration.

Configure BGP Weight Attribute:

Display the BGP IP route for R1, and R4.

R1#sh ip route bgp

B 192.168.4.0/24 [20/0] via 10.200.13.2, 00:53:43

B 192.168.3.0/24 [20/0] via 10.200.13.2, 00:54:43

R4#sh ip route bgp

172.16.0.0/24 is subnetted, 1 subnets

B 172.16.1.0 [200/0] via 3.3.3.3, 00:39:18

Let’s assume that we want to route traffic for 192.168.4.0/24, and 172.16.1.0/24 through AS 65102 (R2). The easiest (but not always best) way to do this is by using BGP’s weight attribute.

1. On R1 create a prefix-list named NET-4 to permit network 192.168.4.0/24
2. On R1 create a route-map named RM-WEIGHT to set the weight of all traffic matching our prefix-list to 100.
3. Apply the route-map to the 65102 neighbor.
4. On 41 create a prefix-list named NET-172 to permit network 172.16.1.0/24
5. On R4 create a route-map named RM-WEIGHT to set the weight of all traffic matching our prefix-list to 100.
6. Apply the route-map to the 65102 neighbor.
7. Use the clear ip bgp command to reset the BGP process so that our change will take effect.
8. Verify the changes made to the BGP routing process.

R1#sh ip route bgp

B 192.168.4.0/24 [20/0] via 10.200.12.2, 00:04:25

B 192.168.3.0/24 [20/0] via 10.200.13.2, 00:04:46

R4#sh ip route bgp

172.16.0.0/24 is subnetted, 1 subnets

B 172.16.1.0 [20/0] via 10.200.24.1, 00:08:02

This concludes this Free CCNP GNS3 lab.

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  BGP-Weight (148.8 KiB, 2,249 hits)