Refer to the diagram:
To reach 10.1.1.1 R3 has to get to 10.0.0.1 as shown in traceroute:
R3#traceroute 10.1.1.1
Type escape sequence to abort.
Tracing the route to 10.1.1.1
1 10.0.0.1 0 msec 0 msec *
R3#
R3#ping 10.1.1.1 repeat 100000
I will shut down R1’s fa0/0 and see if the there were any lost.
Tserver#3
[Resuming connection 3 to 2651-3 … ]
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!……
*Mar 1 14:26:01.195: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 10.0.0.1 (FastEthernet0/0) is down: holding time expired
*Mar 1 14:26:01.195: IP-EIGRP(Default-IP-Routing-Table:100): route installed for 10.0.1.0 ()
*Mar 1 14:26:01.211: IP-EIGRP(Default-IP-Routing-Table:100): 10.1.1.0/24 – do advertise out FastEthernet0/0
*Mar 1 14:26:01.211: IP-EIGRP(Default-IP-Routing-Table:100): Int 10.1.1.0/24 metric 4294967295 – 25600 4294967295
*Mar 1 14:26:01.211: IP-EIGRP(Default-IP-Routing-Table:100): Processing incoming UPDATE packet
*Mar 1 14:26:01.215: IP-EIGRP(Default-IP-Routing-Table:100): Int 10.1.1.0/24 M 5642496 – 4999936 642560 SM 5639936 – 4999936 640000
*Mar 1 14:26:01.227: IP-EIGRP(Default-IP-Routing-Table:100): Processing incoming REPLY packet
*Mar 1 14:26:01.227: IP-EIGRP(Default-IP-Routing-Table:100): Int 10.1.1.0/24 M 5642496 – 4999936 642560 SM 5639936 – 4999936 640000
*Mar 1 14:26:01.231: IP-EIGRP(Default-IP-Routing-Table:100): route installed for 10.1.1.0 ().!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Actually I do not feel it is very fast… I could see 6 loses… From the debug ip eigrp 100, the feasible successor 10.0.1.0/24 route (serial link) is put into the routing table immediately when the successor route 10.0.0.1 was down.
R3#traceroute 10.1.1.1
Type escape sequence to abort.
Tracing the route to 10.1.1.1
1 10.0.0.2 0 msec 0 msec 4 msec
2 10.0.1.1 4 msec 4 msec *
R3#
R1#sh ip eigrp neighbors
IP-EIGRP neighbors for process 100
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
0 10.0.1.2 Se0/0 13 00:33:25 140 840 0 35
R1#sh ip eigrp topology
IP-EIGRP Topology Table for AS(100)/ID(10.1.1.1)
Codes: P – Passive, A – Active, U – Update, Q – Query, R – Reply,
r – reply Status, s – sia Status
P 10.0.0.0/24, 1 successors, FD is 5514496
via 10.0.1.2 (5514496/28160), Serial0/0
P 10.1.1.0/24, 1 successors, FD is 128256
via Connected, Loopback1
P 10.0.1.0/24, 1 successors, FD is 5511936
via Connected, Serial0/0
P 172.30.100.0/30, 1 successors, FD is 5642496
via 10.0.1.2 (5642496/156160), Serial0/0
R1#
R1(config-if)#int fa0/0
R1(config-if)#no shut
R1(config-if)#
*Mar 2 11:11:07.916: %LINK-3-UPDOWN: Interface FastEthernet0/0, changed state to up
R1(config-if)#
*Mar 2 11:11:10.517: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up
*Mar 2 11:11:10.537: IP-EIGRP(Default-IP-Routing-Table:100): 10.0.0.0/24 – do advertise out Serial0/0
*Mar 2 11:11:10.537: IP-EIGRP(Default-IP-Routing-Table:100): Int 10.0.0.0/24 metric 4294967295 – 4999936 4294967295
*Mar 2 11:11:10.565: IP-EIGRP(Default-IP-Routing-Table:100): Processing incoming REPLY packet
*Mar 2 11:11:10.565: IP-EIGRP(Default-IP-Routing-Table:100): Int 10.0.0.0/24 M 5514496 – 4999936 514560 SM 28160 – 25600 2560
*Mar 2 11:11:10.565: IP-EIGRP(Default-IP-Routing-Table:100): 10.0.0.0/24 routing table not updated thru 10.0.1.2
*Mar 2 11:11:10.581: IP-EIGRP(Default-IP-Routing-Table:100): 10.0.0.0/24 – do advertise out Serial0/0
R1(config-if)#
*Mar 2 11:11:10.581: IP-EIGRP(Default-IP-Routing-Table:100): Int 10.0.0.0/24 metric 28160 – 25600 2560
R1(config-if)#
cyruslab 