Section 3: BGP (12 Points)


  • Configure EBGP between R6 and BB3. R6 will be 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 5-28, 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 5-28 shows the BGP configuration on R6. The no synchronization command that you might see referred to a lot of times makes routes not synchronized between BGP and IGP protocols. This way, the IGP will carry fewer routes and allow BGP to converge quickly.

Example 5-28. R6 EBGP Configuration
 R6#show run | b router bgp router bgp 100  no synchronization  neighbor 170.100.10.254 remote-as 300 ! ! R6#show ip bgp BGP table version is 141, local router ID is 170.100.10.1 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 *> 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 *> 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 direct to R6. R2 and R3 should be able to see all BGP BB3 routes in their routing tables. Refer to Figure 5-11. Use the loopbacks to make up your peers.

If you configured this correctly as shown in Example 5-29, you have scored 3 points.

You can choose either Confederations or Router-Reflectors to accomplish this task. The solution demonstrated here shows a solution using Router-Reflectors.

Example 5-29. 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 ! R2 peer only with R3 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! ! 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 R6# 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# R6# ! 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 R2 such that all BGP routes learned from R3 will have weight 40000.

If you configured this correctly as shown in Example 5-30, you have scored 3 points.

This can be accomplished configuring the neighbor weight command or you can also use a route map.

Example 5-30. R2 Weight Configuration
 R2# 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  neighbor 160.10.3.3 weight 40000  no auto-summary! ! 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  40000 300 i *>i198.18.2.0       160.10.6.6               0    100  40000 300 i *>i198.18.3.0       160.10.6.6               0    100  40000 300 i *>i198.18.4.0       160.10.6.6               0    100  40000 300 i *>i198.18.5.0       160.10.6.6               0    100  40000 300 i *>i198.18.6.0       160.10.6.6               0    100  40000 300 i *>i198.18.7.0       160.10.6.6               0    100  40000 300 i *>i198.18.8.0       160.10.6.6               0    100  40000 300 i *>i198.18.9.0       160.10.6.6               0    100  40000 300 i *>i198.18.10.0      160.10.6.6               0    100  40000 300 i *>i200.20.1.0       160.10.6.6               0    100  40000 300 i *>i200.20.2.0       160.10.6.6               0    100  40000 300 i *>i200.20.3.0       160.10.6.6               0    100  40000 300 i *>i200.20.4.0       160.10.6.6               0    100  40000 300 i *>i200.20.5.0       160.10.6.6               0    100  40000 300 i *>i200.20.6.0       160.10.6.6               0    100  40000 300 i *>i200.20.7.0       160.10.6.6               0    100  40000 300 i    Network          Next Hop            Metric LocPrf Weight Path *>i200.20.8.0       160.10.6.6               0    100  40000 300 i *>i200.20.9.0       160.10.6.6               0    100  40000 300 i *>i200.20.10.0      160.10.6.6               0    100  40000 300 i R2# 




CCIE Routing and Switching Practice Labs
CCIE Routing and Switching Practice Labs
ISBN: 1587051478
EAN: 2147483647
Year: 2006
Pages: 268

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