If you configured this correctly as shown in Example 6-36, you have scored 6 points. The EBGP configuration on R6 is a simple task. Again, you will need the basic BGP concepts to accomplish this. Example 6-36. R6 EBGP ConfigurationR6#show run | b router bgp router bgp 100 no synchronization neighbor 170.100.10.254 remote-as 300 no auto-summary ! ! R6# sh ip bgp BGP table version is 21, local router ID is 160.10.6.6 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 *> 198.18.1.0 170.100.10.254 0 0 300 i *> 198.18.2.0 170.100.10.254 0 0 300 i *> 198.18.3.0 170.100.10.254 0 0 300 i *> 198.18.4.0 170.100.10.254 0 0 300 i *> 198.18.5.0 170.100.10.254 0 0 300 i *> 198.18.6.0 170.100.10.254 0 0 300 i *> 198.18.7.0 170.100.10.254 0 0 300 i *> 198.18.8.0 170.100.10.254 0 0 300 i *> 198.18.9.0 170.100.10.254 0 0 300 i *> 198.18.10.0 170.100.10.254 0 0 300 i *> 200.20.1.0 170.100.10.254 0 0 300 i *> 200.20.2.0 170.100.10.254 0 0 300 i *> 200.20.3.0 170.100.10.254 0 0 300 i *> 200.20.4.0 170.100.10.254 0 0 300 i *> 200.20.5.0 170.100.10.254 0 0 300 i *> 200.20.6.0 170.100.10.254 0 0 300 i *> 200.20.7.0 170.100.10.254 0 0 300 i *> 200.20.8.0 170.100.10.254 0 0 300 i Network Next Hop Metric LocPrf Weight Path *> 200.20.9.0 170.100.10.254 0 0 300 i *> 200.20.10.0 170.100.10.254 0 0 300 i R6#
If you configured this correctly as shown in Example 6-37, you have scored 3 points. You can choose either Confederations or Router-Reflectors to accomplish this task. Example 6-37 shows a solution using Router-Reflectors. Example 6-37. R2, R3, and R6 IBGP ConfigurationR2#show run | b router bgp router bgp 100 no synchronization bgp log-neighbor-changes neighbor 160.10.3.3 remote-as 100 neighbor 160.10.3.3 update-source Loopback0 no auto-summary ! R2#show ip bgp sum BGP router identifier 160.10.2.2, local AS number 100 BGP table version is 21, main routing table version 21 20 network entries using 2020 bytes of memory 20 path entries using 960 bytes of memory 1 BGP path attribute entries using 60 bytes of memory 1 BGP rrinfo entries using 24 bytes of memory 1 BGP AS-PATH entries using 24 bytes of memory 0 BGP route-map cache entries using 0 bytes of memory 0 BGP filter-list cache entries using 0 bytes of memory BGP using 3088 total bytes of memory BGP activity 20/0 prefixes, 20/0 paths, scan interval 60 secs Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 160.10.3.3 4 100 30 29 21 0 0 00:12:14 20 R2# ! R2#sh ip bgp BGP table version is 21, local router ID is 160.10.2.2 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 *>i198.18.1.0 160.10.6.6 0 100 0 300 i *>i198.18.2.0 160.10.6.6 0 100 0 300 i *>i198.18.3.0 160.10.6.6 0 100 0 300 i *>i198.18.4.0 160.10.6.6 0 100 0 300 i *>i198.18.5.0 160.10.6.6 0 100 0 300 i *>i198.18.6.0 160.10.6.6 0 100 0 300 i *>i198.18.7.0 160.10.6.6 0 100 0 300 i *>i198.18.8.0 160.10.6.6 0 100 0 300 i *>i198.18.9.0 160.10.6.6 0 100 0 300 i *>i198.18.10.0 160.10.6.6 0 100 0 300 i *>i200.20.1.0 160.10.6.6 0 100 0 300 i *>i200.20.2.0 160.10.6.6 0 100 0 300 i *>i200.20.3.0 160.10.6.6 0 100 0 300 i *>i200.20.4.0 160.10.6.6 0 100 0 300 i *>i200.20.5.0 160.10.6.6 0 100 0 300 i *>i200.20.6.0 160.10.6.6 0 100 0 300 i *>i200.20.7.0 160.10.6.6 0 100 0 300 i Network Next Hop Metric LocPrf Weight Path *>i200.20.8.0 160.10.6.6 0 100 0 300 i *>i200.20.9.0 160.10.6.6 0 100 0 300 i *>i200.20.10.0 160.10.6.6 0 100 0 300 i R2# ! ________________________________________________________________ R3#show run | b router bgp router bgp 100 no synchronization bgp log-neighbor-changes neighbor 160.10.2.2 remote-as 100 neighbor 160.10.2.2 update-source Loopback0 neighbor 160.10.2.2 route-reflector-client neighbor 160.10.6.6 remote-as 100 neighbor 160.10.6.6 update-source Loopback0 neighbor 160.10.6.6 route-reflector-client ! ! R3#show ip bgp sum BGP router identifier 160.10.3.3, local AS number 100 BGP table version is 21, main routing table version 21 20 network entries using 1940 bytes of memory 20 path entries using 720 bytes of memory 1 BGP path attribute entries using 60 bytes of memory 1 BGP AS-PATH entries using 24 bytes of memory 0 BGP route-map cache entries using 0 bytes of memory 0 BGP filter-list cache entries using 0 bytes of memory BGP using 2744 total bytes of memory BGP activity 40/20 prefixes, 40/20 paths, scan interval 60 secs Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 160.10.2.2 4 100 31 32 21 0 0 00:14:54 0 160.10.6.6 4 100 33 30 21 0 0 00:13:55 20 R3# ! R3#sh ip bgp BGP table version is 21, local router ID is 160.10.3.3 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 *>i198.18.1.0 160.10.6.6 0 100 0 300 i *>i198.18.2.0 160.10.6.6 0 100 0 300 i *>i198.18.3.0 160.10.6.6 0 100 0 300 i *>i198.18.4.0 160.10.6.6 0 100 0 300 i *>i198.18.5.0 160.10.6.6 0 100 0 300 i *>i198.18.6.0 160.10.6.6 0 100 0 300 i *>i198.18.7.0 160.10.6.6 0 100 0 300 i *>i198.18.8.0 160.10.6.6 0 100 0 300 i *>i198.18.9.0 160.10.6.6 0 100 0 300 i *>i198.18.10.0 160.10.6.6 0 100 0 300 i *>i200.20.1.0 160.10.6.6 0 100 0 300 i *>i200.20.2.0 160.10.6.6 0 100 0 300 i *>i200.20.3.0 160.10.6.6 0 100 0 300 i *>i200.20.4.0 160.10.6.6 0 100 0 300 i *>i200.20.5.0 160.10.6.6 0 100 0 300 i *>i200.20.6.0 160.10.6.6 0 100 0 300 i *>i200.20.7.0 160.10.6.6 0 100 0 300 i *>i200.20.8.0 160.10.6.6 0 100 0 300 i Network Next Hop Metric LocPrf Weight Path *>i200.20.9.0 160.10.6.6 0 100 0 300 i *>i200.20.10.0 160.10.6.6 0 100 0 300 i R3# ! ________________________________________________________________ R6#show run | b router bgp router bgp 100 no synchronization bgp log-neighbor-changes neighbor 160.10.3.3 remote-as 100 neighbor 160.10.3.3 update-source Loopback0 neighbor 160.10.3.3 next-hop-self neighbor 170.100.10.254 remote-as 300 ! R6#show ip bgp sum BGP router identifier 160.10.6.6, local AS number 100 BGP table version is 21, main routing table version 21 20 network entries using 1940 bytes of memory 20 path entries using 720 bytes of memory 1 BGP path attribute entries using 60 bytes of memory 1 BGP AS-PATH entries using 24 bytes of memory 0 BGP route-map cache entries using 0 bytes of memory 0 BGP filter-list cache entries using 0 bytes of memory BGP using 2744 total bytes of memory BGP activity 20/0 prefixes, 20/0 paths, scan interval 60 secs Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 160.10.3.3 4 100 33 36 21 0 0 00:16:01 0 170.100.10.254 4 300 38 37 21 0 0 00:33:36 20 R6#
R2 is peering with R3 using AS100 (IBGP) and you cannot change it. To make an EBGP peering between R2 and R4 using AS24 you can configure it using "Confederations," which was a restriction to use or the "local-as," which is a BGP feature. If you configured this correctly as shown in Example 6-38, you have scored 3 points. Example 6-38. R2 and R4 Output Configuration417R2#sh run | begin router bgp router bgp 100 no synchronization bgp log-neighbor-changes neighbor 160.10.3.3 remote-as 100 neighbor 160.10.3.3 update-source Loopback0 neighbor 160.10.38.4 remote-as 42 neighbor 160.10.38.4 local-as 24 no auto-summaryR4#sh run | b router bgp router bgp 42 bgp log-neighbor-changes neighbor 160.10.38.2 remote-as 24 ! ________________________________________________________________ R4#sh ip bgp sum BGP router identifier 160.10.4.4, local AS number 42 BGP table version is 21, main routing table version 21 20 network entries using 1940 bytes of memory 20 path entries using 720 bytes of memory 1 BGP path attribute entries using 60 bytes of memory 1 BGP AS-PATH entries using 24 bytes of memory 0 BGP route-map cache entries using 0 bytes of memory 0 BGP filter-list cache entries using 0 bytes of memory BGP using 2744 total bytes of memory BGP activity 20/0 prefixes, 20/0 paths, scan interval 60 secs Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 160.10.38.2 4 24 32 31 21 0 0 00:27:24 20 R4# R4#show ip bgp BGP table version is 21, local router ID is 160.10.4.4 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 *> 198.18.1.0 160.10.38.2 0 24 100 300 i *> 198.18.2.0 160.10.38.2 0 24 100 300 i *> 198.18.3.0 160.10.38.2 0 24 100 300 i *> 198.18.4.0 160.10.38.2 0 24 100 300 i *> 198.18.5.0 160.10.38.2 0 24 100 300 i *> 198.18.6.0 160.10.38.2 0 24 100 300 i *> 198.18.7.0 160.10.38.2 0 24 100 300 i *> 198.18.8.0 160.10.38.2 0 24 100 300 i *> 198.18.9.0 160.10.38.2 0 24 100 300 i *> 198.18.10.0 160.10.38.2 0 24 100 300 i *> 200.20.1.0 160.10.38.2 0 24 100 300 i *> 200.20.2.0 160.10.38.2 0 24 100 300 i *> 200.20.3.0 160.10.38.2 0 24 100 300 i *> 200.20.4.0 160.10.38.2 0 24 100 300 i *> 200.20.5.0 160.10.38.2 0 24 100 300 i *> 200.20.6.0 160.10.38.2 0 24 100 300 i *> 200.20.7.0 160.10.38.2 0 24 100 300 i *> 200.20.8.0 160.10.38.2 0 24 100 300 i Network Next Hop Metric LocPrf Weight Path *> 200.20.9.0 160.10.38.2 0 24 100 300 i *> 200.20.10.0 160.10.38.2 0 24 100 300 i R4# |