Task 5 FYI, the question is truncated.... 1. r2 should aggregate all the networks in 3.1.0.0 address space........... 2. Aggregation should be configured such that R1 in AS 100 is the only AS that receives the aggregate route, R3 and future peer neighbors should NOT receive the aggregate route. 1. r2 should aggregate all the networks in 3.1.0.0 address space........... r2 router bgp 200 aggregate-address 3.1.0.0 255.255.240.0 summary-only as-set Verification: R1(config-if)#do sho ip bgp BGP table version is 3, local router ID is 10.1.12.1 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 2.2.2.0/24 10.1.12.2 0 0 200 i *> 3.1.11.0/24 0.0.0.0 0 32768 i R1(config-if)#do sho ip bgp nei 10.1.12.2 route <---------------- this command shows me the routes I reeived and ACCEPTED. BGP table version is 3, local router ID is 10.1.12.1 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 2.2.2.0/24 10.1.12.2 0 0 200 i R2(config-router)#do sho ip bgp BGP table version is 87, local router ID is 2.2.3.2 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 2.2.2.0/24 0.0.0.0 0 32768 i s> 3.1.0.0/24 10.1.23.3 0 0 300 i *> 3.1.0.0/20 0.0.0.0 100 32768 {300,100} i s> 3.1.1.0/24 10.1.23.3 0 0 300 i s> 3.1.2.0/24 10.1.23.3 0 0 300 i s> 3.1.3.0/24 10.1.23.3 0 0 300 i s> 3.1.4.0/24 10.1.23.3 0 0 300 i s> 3.1.5.0/24 10.1.23.3 0 0 300 i s> 3.1.6.0/24 10.1.23.3 0 0 300 i s> 3.1.7.0/24 10.1.23.3 0 0 300 i s> 3.1.8.0/24 10.1.23.3 0 0 300 i s> 3.1.9.0/24 10.1.23.3 0 0 300 i s> 3.1.10.0/24 10.1.23.3 0 0 300 i s> 3.1.11.0/24 10.1.12.1 0 0 100 i s> 3.1.12.0/24 10.1.23.3 0 0 300 i s> 3.1.13.0/24 10.1.23.3 0 0 300 i s> 3.1.14.0/24 10.1.23.3 0 0 300 i Network Next Hop Metric LocPrf Weight Path s> 3.1.15.0/24 10.1.23.3 0 0 300 i R2(config-router)#do sho ip bgp nei 10.1.12.1 adver <------------ this shows me what I am advertising to my peer. BGP table version is 87, local router ID is 2.2.3.2 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 2.2.2.0/24 0.0.0.0 0 32768 i *> 3.1.0.0/20 0.0.0.0 100 32768 {300,100} i <-------------- {300,100} you see that because I added the as-set command Total number of prefixes 2 R2(config-router)#do sho ip bgp nei 10.1.23.3 adver <------------ this shows me what I am advertising to my peer. BGP table version is 87, local router ID is 2.2.3.2 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 2.2.2.0/24 0.0.0.0 0 32768 i *> 3.1.0.0/20 0.0.0.0 100 32768 {300,100} i <-------------- {300,100} you see that because I added the as-set command R3(config-router)#do sho ip bgp BGP table version is 17, local router ID is 3.1.15.3 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 2.2.2.0/24 10.1.23.2 0 0 200 i *> 3.1.0.0/24 0.0.0.0 0 32768 i *> 3.1.1.0/24 0.0.0.0 0 32768 i *> 3.1.2.0/24 0.0.0.0 0 32768 i *> 3.1.3.0/24 0.0.0.0 0 32768 i *> 3.1.4.0/24 0.0.0.0 0 32768 i *> 3.1.5.0/24 0.0.0.0 0 32768 i *> 3.1.6.0/24 0.0.0.0 0 32768 i *> 3.1.7.0/24 0.0.0.0 0 32768 i *> 3.1.8.0/24 0.0.0.0 0 32768 i *> 3.1.9.0/24 0.0.0.0 0 32768 i *> 3.1.10.0/24 0.0.0.0 0 32768 i *> 3.1.12.0/24 0.0.0.0 0 32768 i *> 3.1.13.0/24 0.0.0.0 0 32768 i *> 3.1.14.0/24 0.0.0.0 0 32768 i *> 3.1.15.0/24 0.0.0.0 0 32768 i R3(config-router)#do sho ip bgp nei 10.1.23.2 route <---------------- this command shows me the routes I received and ACCEPTED. BGP table version is 17, local router ID is 3.1.15.3 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 2.2.2.0/24 10.1.23.2 0 0 200 i So looking at this R2 is advertising the aggregated route to R1 and R3 but they are not installing in the BGP table. 2. Aggregation should be configured such that R1 in AS 100 is the only AS that receives the aggregate route, R3 and future peer neighbors should NOT receive the aggregate route. solution r2 ip as-path access-list 1 per ^300$ <------------ So with the as-path list /route-map we are telling the aggregate-address in what AS the routes originated. We do not have to worry about the aggregate route being advertised to AS 300 because it will dropped anyway due to loop avoidance because AS 300 will see that it came from AS 300. route-map TST 10 match as-path 1 router bgp 200 aggregate-address 3.1.0.0 255.255.240.0 summary-only as-set advertise-map TST Using the advertise-map keyword selects specific routes that will be used to build different components of the aggregate route, such as AS_SET or community. This form of the aggregate-address command is useful when the components of an aggregate are in separate autonomous systems and you want to create an aggregate with AS_SET, and advertise it back to some of the same autonomous systems. You must remember to omit the specific autonomous system numbers from the AS_SET to prevent the aggregate from being dropped by the BGP loop detection mechanism at the receiving router. IP access lists and autonomous system path access lists match clauses are supported. R1(config-if)#do sho ip bgp BGP table version is 6, local router ID is 10.1.12.1 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 2.2.2.0/24 10.1.12.2 0 0 200 i *> 3.1.0.0/20 10.1.12.2 0 0 200 300 i *> 3.1.11.0/24 0.0.0.0 0 32768 i