Below shows the routing table and EIGRP topology table on RT1:
RT1#sh ip route Gateway of last resort is not set 172.16.0.0/24 is subnetted, 1 subnets D 172.16.1.0 [90/2172416] via 10.10.10.2, 00:00:03, Serial0/0 10.0.0.0/30 is subnetted, 3 subnets D 10.10.10.8 [90/2681856] via 10.10.10.2, 00:00:05, Serial0/0 [90/2681856] via 10.10.10.6, 00:00:05, Serial0/1 C 10.10.10.0 is directly connected, Serial0/0 C 10.10.10.4 is directly connected, Serial0/1 RT1# RT1#sh ip eigrp topology IP-EIGRP Topology Table for AS(100)/ID(10.10.10.5) Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply, r - reply Status, s - sia Status P 10.10.10.8/30, 2 successors, FD is 2681856 via 10.10.10.6 (2681856/2169856), Serial0/1 via 10.10.10.2 (2681856/2169856), Serial0/0 P 10.10.10.0/30, 1 successors, FD is 2169856 via Connected, Serial0/0 P 10.10.10.4/30, 1 successors, FD is 2169856 via Connected, Serial0/1 P 172.16.1.0/24, 1 successors, FD is 2172416 via 10.10.10.2 (2172416/28160), Serial0/0 RT1# RT1#sh ip eigrp topology all-links IP-EIGRP Topology Table for AS(100)/ID(10.10.10.5) Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply, r - reply Status, s - sia Status P 10.10.10.8/30, 2 successors, FD is 2681856, serno 6 via 10.10.10.6 (2681856/2169856), Serial0/1 via 10.10.10.2 (2681856/2169856), Serial0/0 P 10.10.10.0/30, 1 successors, FD is 2169856, serno 3 via Connected, Serial0/0 P 10.10.10.4/30, 1 successors, FD is 2169856, serno 2 via Connected, Serial0/1 P 172.16.1.0/24, 1 successors, FD is 2172416, serno 4 via 10.10.10.2 (2172416/28160), Serial0/0 via 10.10.10.6 (2684416/2172416), Serial0/1 RT1# RT1#sh ip eigrp topo 172.16.1.0/24 IP-EIGRP (AS 100): Topology entry for 172.16.1.0/24 State is Passive, Query origin flag is 1, 1 Successor(s), FD is 2172416 Routing Descriptor Blocks: 10.10.10.2 (Serial0/0), from 10.10.10.2, Send flag is 0x0 Composite metric is (2172416/28160), Route is Internal Vector metric: Minimum bandwidth is 1544 Kbit Total delay is 20100 microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 1 10.10.10.6 (Serial0/1), from 10.10.10.6, Send flag is 0x0 Composite metric is (2684416/2172416), Route is Internal Vector metric: Minimum bandwidth is 1544 Kbit Total delay is 40100 microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 2 RT1#debug ip eigrp IP-EIGRP Route Events debugging is on RT1#debug ip routing IP routing debugging is on RT1#debug eigrp fsm EIGRP FSM Events/Actions debugging is on RT1#Note: The advertised distance from RT3 (10.10.10.6) to reach 172.16.1.0/24 is 2172416, which is same and not less than RT1’s feasible distance. Therefore it is not considered as a FS.
Below shows the EIGRP topology table on RT3 and modifying the delay value of S0/1.
RT3#sh ip eigrp topo IP-EIGRP Topology Table for AS(100)/ID(10.10.10.10) Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply, r - reply Status, s - sia Status P 10.10.10.8/30, 1 successors, FD is 2169856 via Connected, Serial0/1 P 10.10.10.0/30, 2 successors, FD is 2681856 via 10.10.10.9 (2681856/2169856), Serial0/1 via 10.10.10.5 (2681856/2169856), Serial0/0 P 10.10.10.4/30, 1 successors, FD is 2169856 via Connected, Serial0/0 P 172.16.1.0/24, 1 successors, FD is 2172416 via 10.10.10.9 (2172416/28160), Serial0/1 RT3# RT3#sh int s0/1 | in DLY MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, RT3#conf t Enter configuration commands, one per line. End with CNTL/Z. RT3(config)#int s0/1 RT3(config-if)#delay 1999 RT3(config-if)#do sh int s0/1 | in DLY MTU 1500 bytes, BW 1544 Kbit, DLY 19990 usec, RT3(config-if)#
Below shows the EIGRP convergence on RT1 upon changing the delay on RT3 S0/1:
RT1#
00:03:25: IP-EIGRP(Default-IP-Routing-Table:100): Processing incoming UPDATE packet
00:03:25: IP-EIGRP(Default-IP-Routing-Table:100): Int 10.10.10.8/30 M 2681600 - 1657856 1023744 SM 2169600 - 1657856 511744
00:03:25: DUAL: rcvupdate: 10.10.10.8/30 via 10.10.10.6 metric 2681600/2169600
00:03:25: DUAL: Find FS for dest 10.10.10.8/30. FD is 2681856, RD is 2681856
00:03:25: DUAL: 10.10.10.6 metric 2681600/2169600
00:03:25: DUAL: 10.10.10.2 metric 2681856/2169856 found Dmin is 2681600
00:03:25: RT: metric change to 10.10.10.8 via 10.10.10.6, eigrp metric [90/2681856]
new metric [90/2681600]
00:03:25: RT: del 10.10.10.8/30 via 10.10.10.2, eigrp metric [90/2681856]
00:03:25: RT: NET-RED 10.10.10.8/30
00:03:25: RT: NET-RED 10.10.10.8/30
00:03:25: DUAL: RT installed 10.10.10.8/30 via 10.10.10.6
00:03:25: IP-EIGRP(Default-IP-Routing-Table:100): 10.10.10.8/30 routing table not updated thru 10.10.10.2
00:03:25: DUAL: Send update about 10.10.10.8/30. Reason: metric chg
00:03:25: DUAL: Send update about 10.10.10.8/30. Reason: lost if
00:03:25: IP-EIGRP(Default-IP-Routing-Table:100): 10.10.10.8/30 - do advertise out Serial0/0
00:03:25: IP-EIGRP(Default-IP-Routing-Table:100): Int 10.10.10.8/30 metric 2681600 - 1657856 1023744
00:03:25: IP-EIGRP(Default-IP-Routing-Table:100): Int 10.10.10.8/30 metric 2681600 - 1657856 1023744
00:03:35: IP-EIGRP(Default-IP-Routing-Table:100): Processing incoming UPDATE packet
00:03:35: IP-EIGRP(Default-IP-Routing-Table:100): Int 10.10.10.0/30 M 3193600 - 1657856 1535744 SM 2681600 - 1657856 1023744
00:03:35: DUAL: dest(10.10.10.0/30) not active
00:03:35: DUAL: rcvupdate: 10.10.10.0/30 via 10.10.10.6 metric 3193600/2681600
00:03:35: DUAL: Find FS for dest 10.10.10.0/30. FD is 2169856, RD is 2169856
00:03:35: DUAL: 0.0.0.0 metric 2169856/0
00:03:35: DUAL: 10.10.10.6 metric 3193600/2681600 found Dmin is 2169856
00:03:35: IP-EIGRP(Default-IP-Routing-Table:100): 10.10.10.0/30 routing table not updated thru 10.10.10.6
00:03:35: IP-EIGRP(Default-IP-Routing-Table:100): Int 172.16.1.0/24 M 2684160 - 1657856 1026304 SM 2172160 - 1657856 514304
00:03:35: DUAL: rcvupdate: 172.16.1.0/24 via 10.10.10.6 metric 2684160/2172160
00:03:35: DUAL: Find FS for dest 172.16.1.0/24. FD is 2172416, RD is 2172416
00:03:35: DUAL: 10.10.10.2 metric 2172416/28160
00:03:35: DUAL: 10.10.10.6 metric 2684160/2172160 found Dmin is 2172416
00:03:35: DUAL: RT installed 172.16.1.0/24 via 10.10.10.2
00:03:35: IP-EIGRP(Default-IP-Routing-Table:100): 172.16.1.0/24 routing table not updated thru 10.10.10.6
RT1#
RT1#sh ip eigrp topo
IP-EIGRP Topology Table for AS(100)/ID(10.10.10.5)
Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
r - reply Status, s - sia Status
P 10.10.10.8/30, 1 successors, FD is 2681600
via 10.10.10.6 (2681600/2169600), Serial0/1
via 10.10.10.2 (2681856/2169856), Serial0/0
P 10.10.10.0/30, 1 successors, FD is 2169856
via Connected, Serial0/0
P 10.10.10.4/30, 1 successors, FD is 2169856
via Connected, Serial0/1
P 172.16.1.0/24, 1 successors, FD is 2172416
via 10.10.10.2 (2172416/28160), Serial0/0
via 10.10.10.6 (2684160/2172160), Serial0/1
RT1#
The path to 172.16.1.0/24 from RT1 to RT2 via RT3 has become a feasible successor (backup) as the advertise distance from RT3, 2172160 is less than RT1’s feasible distance, 2172416.
Below simulates a network connectivity problem by applying an access list to prevent RT2 EIGRP Hello packets from reaching to RT1 S0/0.
RT1#conf t Enter configuration commands, one per line. End with CNTL/Z. RT1(config)#access-list 101 deny eigrp any host 224.0.0.10 RT1(config)#int s0/0 RT1(config-if)#ip access-group 101 in RT1(config-if)#^Z RT1# RT1#sh ip eigrp neighbors IP-EIGRP neighbors for process 100 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num 1 10.10.10.6 Se0/1 10 00:02:17 347 2082 0 10 0 10.10.10.2 Se0/0 5 00:02:32 486 2916 0 6 RT1#
Below shows the output messages of the debug ip eigrp, debug ip routing, and debug eigrp fsm privileged command on RT1 for EIGRP convergence upon the connectivity problem. The EIGRP Query-Reply process did not occur as there is a FS to the network.
RT1# 00:03:09: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 10.10.10.2 (Seria l0/0) is down: holding time expired 00:03:09: DUAL: linkdown: start - 10.10.10.2 via Serial0/0 00:03:09: DUAL: Destination 10.10.10.8/30 00:03:09: DUAL: Removing dest 10.10.10.8/30, nexthop 10.10.10.2 00:03:09: DUAL: Destination 10.10.10.0/30 00:03:09: DUAL: Destination 10.10.10.4/30 00:03:09: DUAL: Destination 172.16.1.0/24 00:03:09: DUAL: Find FS for dest 172.16.1.0/24. FD is 2172416, RD is 2172416 00:03:09: DUAL: 10.10.10.2 metric 4294967295/4294967295 00:03:09: DUAL: 10.10.10.6 metric 2684160/2172160 found Dmin is 2684160 00:03:09: RT: delete route to 172.16.1.0 via 10.10.10.2, eigrp metric [90/2172416] 00:03:09: RT: no routes to 172.16.1.0 00:03:09: RT: NET-RED 172.16.1.0/24 00:03:09: RT: delete subnet route to 172.16.1.0/24 00:03:09: RT: NET-RED 172.16.1.0/24 00:03:09: RT: delete network route to 172.16.0.0 00:03:09: RT: NET-RED 172.16.0.0/16 00:03:09: DUAL: Removing dest 172.16.1.0/24, nexthop 10.10.10.2 00:03:09: RT: add 172.16.1.0/24 via 10.10.10.6, eigrp metric [90/2684160] 00:03:09: RT: NET-RED 172.16.1.0/24 00:03:09: DUAL: RT installed 172.16.1.0/24 via 10.10.10.6 00:03:09: DUAL: Send update about 172.16.1.0/24. Reason: metric chg 00:03:09: DUAL: Send update about 172.16.1.0/24. Reason: new if 00:03:09: DUAL: linkdown: finish 00:03:09: IP-EIGRP(Default-IP-Routing-Table:100): Int 172.16.1.0/24 metric 2684160 - 1657856 1026304 RT1# RT1#sh ip eigrp topo IP-EIGRP Topology Table for AS(100)/ID(10.10.10.5) Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply, r - reply Status, s - sia Status P 10.10.10.8/30, 1 successors, FD is 2681600 via 10.10.10.6 (2681600/2169600), Serial0/1 P 10.10.10.0/30, 1 successors, FD is 2169856 via Connected, Serial0/0 P 10.10.10.4/30, 1 successors, FD is 2169856 via Connected, Serial0/1 P 172.16.1.0/24, 1 successors, FD is 2172416 via 10.10.10.6 (2684160/2172160), Serial0/1 RT1# RT1#sh ip route Gateway of last resort is not set 172.16.0.0/24 is subnetted, 1 subnets D 172.16.1.0 [90/2684160] via 10.10.10.6, 00:00:20, Serial0/1 10.0.0.0/30 is subnetted, 3 subnets D 10.10.10.8 [90/2681600] via 10.10.10.6, 00:01:30, Serial0/1 C 10.10.10.0 is directly connected, Serial0/0 C 10.10.10.4 is directly connected, Serial0/1 RT1#
No comments:
Post a Comment