In this Free CCNP Lab we will use the previous GNS3 configured BGP lab and will expand on it by creating a summary address for the 172.16.0.0 network using the Cisco IOS command aggregate-address. The aggregate-address ip-address mask [summary-only] [as-set] router configuration command is used to create an aggregate or summary, entry in the BGP table to network that already exist within the BGP tables. This is different from the requirements for advertising summaries with the BGP network command where the network must exist in the IP routing tables.
In this lab we will be using the summary-only keyword which will advertise only the summary address and the path indicates only the AS that is summarized.
Learning Objectives:
- Summary address.
- Aggregate-address.
- Summary-only keyword.
Tasks:
- Display the existing routing table on R1.
R1#sh ip route
Codes: C – connected, S – static, I – IGRP, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2, E – EGP
i – IS-IS, L1 – IS-IS level-1, L2 – IS-IS level-2, ia – IS-IS inter area
* – candidate default, U – per-user static route, o – ODR
P – periodic downloaded static route
Gateway of last resort is not set
172.16.0.0/16 is variably subnetted, 5 subnets, 2 masks
B 172.16.0.0/24 [200/0] via 192.168.100.2, 00:02:30
B 172.16.1.0/24 [200/0] via 192.168.100.2, 00:02:30
B 172.16.2.0/24 [200/0] via 192.168.100.2, 00:02:30
B 172.16.3.0/24 [200/0] via 192.168.100.2, 00:02:30
B 172.16.100.0/30 [200/0] via 192.168.100.2, 00:02:34
C 192.168.0.0/24 is directly connected, Loopback0
C 192.168.1.0/24 is directly connected, Loopback1
C 192.168.2.0/24 is directly connected, Loopback2
192.168.100.0/30 is subnetted, 1 subnets
C 192.168.100.0 is directly connected, FastEthernet0/0
C 192.168.3.0/24 is directly connected, Loopback3
Note that there are 5 entries in the routing tables to the 172.16.0.0/16 network.
- Display the BGP tables on R1.
R1#sh ip bgp
BGP table version is 11, local router ID is 192.168.3.1
Status codes: s suppressed, d damped, h history, * valid, > best, i – internal
Origin codes: i – IGP, e – EGP, ? – incomplete
Network Next Hop Metric LocPrf Weight Path
*>i172.16.0.0/24 192.168.100.2 100 0 65200 i
*>i172.16.1.0/24 192.168.100.2 100 0 65200 i
*>i172.16.2.0/24 192.168.100.2 100 0 65200 i
*>i172.16.3.0/24 192.168.100.2 100 0 65200 i
*>i172.16.100.0/30 192.168.100.2 0 100 0 65200 i
*> 192.168.0.0 0.0.0.0 0 32768 i
*> 192.168.1.0 0.0.0.0 0 32768 i
*> 192.168.2.0 0.0.0.0 0 32768 i
*> 192.168.3.0 0.0.0.0 0 32768 i
*>i192.168.100.0/30 192.168.100.2 0 100 0 i
Note that there are 5 entries in the BGP tables for the 172.16.0.0/16 network
- Advertise only the summary address for the 172.16.0.0 network.
- Display the routing tables on R1.
R1#sh ip route
Codes: C – connected, S – static, I – IGRP, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2, E – EGP
i – IS-IS, L1 – IS-IS level-1, L2 – IS-IS level-2, ia – IS-IS inter area
* – candidate default, U – per-user static route, o – ODR
P – periodic downloaded static route
Gateway of last resort is not set
B 172.16.0.0/16 [200/0] via 192.168.100.2, 00:05:44
C 192.168.0.0/24 is directly connected, Loopback0
C 192.168.1.0/24 is directly connected, Loopback1
C 192.168.2.0/24 is directly connected, Loopback2
192.168.100.0/30 is subnetted, 1 subnets
C 192.168.100.0 is directly connected, FastEthernet0/0
C 192.168.3.0/24 is directly connected, Loopback3
- Display the BGP tables on R1.
R1#sh ip bgp
BGP table version is 17, local router ID is 192.168.3.1
Status codes: s suppressed, d damped, h history, * valid, > best, i – internal
Origin codes: i – IGP, e – EGP, ? – incomplete
Network Next Hop Metric LocPrf Weight Path
*>i172.16.0.0 192.168.100.2 100 0 65200 i
*> 192.168.0.0 0.0.0.0 0 32768 i
*> 192.168.1.0 0.0.0.0 0 32768 i
*> 192.168.2.0 0.0.0.0 0 32768 i
*> 192.168.3.0 0.0.0.0 0 32768 i
*>i192.168.100.0/30 192.168.100.2 0 100 0 i
Note that now the 172.16.0.0/16 network has been summarized into a single advertised address.
From R1 ping the 172.16.0.1, 172.16.1.1, 172.16.2.1, and 172.16.3.1 address and insure they can be reached.
This concludes this free CCNP BGP summary address GNS3 lab.
Download this lab now to see more:
BGP-Summary-Address (159.6 KiB, 1,838 hits)
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