Section 3: BGP (12 Points)
If you configured this correctly as shown in Example 4-28, 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, as shown in Example 4-28. You will also see on R4 BGP routing table that R4 is receiving all BGP routes from Backbone 3. Example 4-28. 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#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#
If you configured this correctly as shown in Example 4-29, you have scored 3 points. You will need to make a fully meshed BGP configuration and make sure R2 and R4 routing tables will be populated with BGP BB3 routes and show the routers as ">" best via R6 Loopback0. As the question requires, make sure to use the loopback interface address to make up your peers. Disabling the synchronization and the next-hop-self statements are keys to making this happen. Example 4-29. R2, R4, and R6 IBGP ConfigurationR2#show run | b router bgp router bgp 100 no synchronization bgp log-neighbor-changes neighbor 160.10.4.4 remote-as 100 neighbor 160.10.4.4 update-source Loopback0 neighbor 160.10.6.6 remote-as 100 neighbor 160.10.6.6 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 1, main routing table version 1 20 network entries and 20 paths using 2740 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 activity 20/80 prefixes, 20/0 paths, scan interval 60 secs Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 160.10.4.4 4 100 103 103 1 0 0 01:39:29 0 160.10.6.6 4 100 105 104 1 0 0 01:40:38 20 R2# ! R2#show 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# ! ________________________________________________________________ R4#show run | b router bgp router bgp 100 bgp log-neighbor-changes neighbor 160.10.2.2 remote-as 100 neighbor 160.10.2.2 update-source Loopback0 neighbor 160.10.6.6 remote-as 100 neighbor 160.10.6.6 update-source Loopback0 ! ! R4#show ip bgp sum BGP router identifier 160.10.4.4, local AS number 100 BGP table version is 1, main routing table version 1 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 160.10.2.2 4 100 104 104 1 0 0 01:40:02 0 160.10.6.6 4 100 105 104 1 0 0 01:40:10 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 *>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 R4# ! ________________________________________________________________ R6#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 next-hop-self neighbor 160.10.4.4 remote-as 100 neighbor 160.10.4.4 update-source Loopback0 neighbor 160.10.4.4 next-hop-self neighbor 170.100.10.254 remote-as 300 ! ! R6#show ip bgp sum BGP router identifier 170.100.10.1, local AS number 100 BGP table version is 141, main routing table version 141 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 80/60 prefixes, 80/60 paths, scan interval 60 secs Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 160.10.2.2 4 100 105 106 141 0 0 01:41:37 0 160.10.4.4 4 100 104 105 141 0 0 01:40:36 0 170.100.10.254 4 300 19073 19069 141 0 0 1w2d 20 R6# ! R6#show 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# ! *> 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 4-30, you have scored 3 points. It is interesting to observe here that the use of the neighbor maximum-prefix command is simple, but you must pay attention to accomplish the requirement to generate a warning when 75 percent is reached, because you do not actually need to configure any threshold. NOTE Seventy-five percent is the default to generate a warning. Verify and study the commands and features noting defaults to avoid you falling into a trap of overconfiguration. Example 4-30. R2 maximum-prefix CommandR2# R2#show run | b router bgp router bgp 100 no synchronization bgp log-neighbor-changes neighbor 160.10.4.4 remote-as 100 neighbor 160.10.4.4 update-source Loopback0 neighbor 160.10.6.6 remote-as 100 neighbor 160.10.6.6 update-source Loopback0 neighbor 160.10.6.6 maximum-prefix 100 no auto-summary ! ! R2#sh ip bgp neighbors 160.10.6.6 BGP neighbor is 160.10.6.6, remote AS 100, internal link BGP version 4, remote router ID 170.100.10.1 BGP state = Established, up for 21:30:03 Last read 00:00:06, hold time is 180, keepalive interval is 60 seconds Neighbor capabilities: Route refresh: advertised and received(old & new) Address family IPv4 Unicast: advertised and received Received 1295 messages, 0 notifications, 0 in queue Sent 1294 messages, 0 notifications, 0 in queue Default minimum time between advertisement runs is 5 seconds For address family: IPv4 Unicast BGP table version 1, neighbor version 1 Index 2, Offset 0, Mask 0x4 Route refresh request: received 0, sent 0 20 accepted prefixes consume 800 bytes Prefix advertised 0, suppressed 0, withdrawn 0, maximum limit 100 Threshold for warning message 75% Connections established 1; dropped 0 Last reset never Connection state is ESTAB, I/O status: 1, unread input bytes: 0 Local host: 160.10.2.2, Local port: 11001 Foreign host: 160.10.6.6, Foreign port: 179 Total option bytes= 4, padded length=4 Basic security: Class: unclassified Auth: genser Enqueued packets for retransmit: 0, input: 0 mis-ordered: 0 (0 bytes) Event Timers (current time is 0x5C88C52C): Timer Starts Wakeups Next Retrans 1296 1 0x0 TimeWait 0 0 0x0 AckHold 1293 1115 0x0 SendWnd 0 0 0x0 KeepAlive 0 0 0x0 GiveUp 0 0 0x0 PmtuAger 0 0 0x0 DeadWait 0 0 0x0 iss: 1084218813 snduna: 1084243426 sndnxt: 1084243426 sndwnd: 16251 irs: 2068401015 rcvnxt: 2068425763 rcvwnd: 16118 delrcvwnd: 266 SRTT: 300 ms, RTTO: 303 ms, RTV: 3 ms, KRTT: 0 ms minRTT: 4 ms, maxRTT: 300 ms, ACK hold: 200 ms Flags: higher precedence, nagle Datagrams (max data segment is 532 bytes): Rcvd: 2566 (out of order: 0), with data: 1293, total data bytes: 24747 Sent: 2458 (retransmit: 1, fastretransmit: 0), with data: 1294, total data bytes: 24612 R2# |
CCIE Routing and Switching Practice Labs
ISBN: 1587051478
EAN: 2147483647
EAN: 2147483647
Year: 2006
Pages: 268
Pages: 268
Authors: Martin J. Duggan, Maurilio P. Gorito