Section 3: BGP (12 Points) | CCIE Routing and Switching Practice Labs

Configure EBGP between R6 and BB3. R6 will belong to AS 100 and the BB3 router AS is 300. R6 will receive updates for networks 200.20.X.0 and 198.18.X.0, where X is any number.

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 Configuration

 R6#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#

Configure IBGP between R2, R3, and R6. Use AS 100. R2 should not peer directly with R6. R2 and R3 should be able to see all BGP BB3 routes in their BGP routing tables.

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 Configuration

 R2#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#

Configure an EBGP peering between R2 to AS 24 and R4 to AS 42. R4 should have all BB3 backbone routes within its BGP routing table. Do not change the R2 affiliation with AS 100 as accomplished in the preceding task and do not use a Confederation to accomplish this.

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 Configuration417

 R2#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#