en conf t int f0/0 ip addr 172.16.2.1 255.255.255.0 no shut int f0/1 ip addr 172.16.1.1 255.255.255.0 no shut end
en conf t int f0/0 ip addr 172.16.2.2 255.255.255.0 no shut int f0/1 ip addr 172.16.1.2 255.255.255.0 no shut end
Using R3 as IRDP Host.
en conf t int f0/0 ip addr 172.16.1.100 255.255.255.0 no shut end
sudo ip route add 172.16.0.0/16 via 172.16.2.2
R1#sh ip ro Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP + - replicated route, % - next hop override Gateway of last resort is not set 172.16.0.0/16 is variably subnetted, 4 subnets, 2 masks C 172.16.1.0/24 is directly connected, FastEthernet0/1 L 172.16.1.1/32 is directly connected, FastEthernet0/1 C 172.16.2.0/24 is directly connected, FastEthernet0/0 L 172.16.2.1/32 is directly connected, FastEthernet0/0
R2#sh ip ro Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP + - replicated route, % - next hop override Gateway of last resort is not set 172.16.0.0/16 is variably subnetted, 4 subnets, 2 masks C 172.16.1.0/24 is directly connected, FastEthernet0/1 L 172.16.1.2/32 is directly connected, FastEthernet0/1 C 172.16.2.0/24 is directly connected, FastEthernet0/0 L 172.16.2.2/32 is directly connected, FastEthernet0/0
R3#sh ip ro Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP + - replicated route, % - next hop override Gateway of last resort is not set 172.16.0.0/16 is variably subnetted, 2 subnets, 2 masks C 172.16.1.0/24 is directly connected, FastEthernet0/0 L 172.16.1.100/32 is directly connected, FastEthernet0/0
R1#conf t Enter configuration commands, one per line. End with CNTL/Z. R1(config)#int f0/1 R1(config-if)#ip irdp R1(config-if)#ip irdp maxadvertinterval 6 R1(config-if)#ip irdp minadvertinterval 3 R1(config-if)#ip irdp holdtime 18 R1(config-if)#ip irdp preference 100 R1(config-if)#end R1# *Mar 4 10:05:09.651: %SYS-5-CONFIG_I: Configured from console by console
R2#conf t Enter configuration commands, one per line. End with CNTL/Z. R2(config)#int f0/1 R2(config-if)#ip irdp R2(config-if)#ip irdp maxadvertinterval 6 R2(config-if)#ip irdp minadvertinterval 3 R2(config-if)#ip irdp holdtime 18 R2(config-if)#ip irdp preference 18 R2(config-if)#end R2# *Mar 4 11:15:21.235: %SYS-5-CONFIG_I: Configured from console by console
This timing, last resort gateway not set.
R3#sh ip ro Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP + - replicated route, % - next hop override Gateway of last resort is not set 172.16.0.0/16 is variably subnetted, 2 subnets, 2 masks C 172.16.1.0/24 is directly connected, FastEthernet0/0 L 172.16.1.100/32 is directly connected, FastEthernet0/0
Now configure IRDP client. This scene, using R3.
R3#conf t Enter configuration commands, one per line. End with CNTL/Z. R3(config)#no ip routing R3(config)#ip gdp ? eigrp Discover routers transmitting EIGRP router updates irdp Discover routers transmitting IRDP router updates rip Discover routers transmitting RIP router updates R3(config)#ip gdp irdp R3(config)#^Z R3# *Mar 4 11:18:28.999: %SYS-5-CONFIG_I: Configured from console by console
R1#sh ip irdp FastEthernet0/0 has router discovery disabled FastEthernet0/1 has router discovery enabled Advertisements will occur between every 3 and 6 seconds. Advertisements are sent with broadcasts. Advertisements are valid for 18 seconds. Default preference will be 100. Serial0/0/0 has router discovery disabled R1#sh ip ro Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP + - replicated route, % - next hop override Gateway of last resort is not set 172.16.0.0/16 is variably subnetted, 4 subnets, 2 masks C 172.16.1.0/24 is directly connected, FastEthernet0/1 L 172.16.1.1/32 is directly connected, FastEthernet0/1 C 172.16.2.0/24 is directly connected, FastEthernet0/0 L 172.16.2.1/32 is directly connected, FastEthernet0/0
R2#sh ip irdp FastEthernet0/0 has router discovery disabled FastEthernet0/1 has router discovery enabled Advertisements will occur between every 3 and 6 seconds. Advertisements are sent with broadcasts. Advertisements are valid for 18 seconds. Default preference will be 18. Serial0/0/0 has router discovery disabled R2#sh ip ro Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP + - replicated route, % - next hop override Gateway of last resort is not set 172.16.0.0/16 is variably subnetted, 4 subnets, 2 masks C 172.16.1.0/24 is directly connected, FastEthernet0/1 L 172.16.1.2/32 is directly connected, FastEthernet0/1 C 172.16.2.0/24 is directly connected, FastEthernet0/0 L 172.16.2.2/32 is directly connected, FastEthernet0/0
R3#ping 172.16.2.250 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 172.16.2.250, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/202/1000 ms R3#tracerou 172.16.2.250 R3#tracerou 172.16.2.250 ? numeric display numeric address port specify port number probe specify number of probes per hop source specify source address or name timeout specify time out ttl specify minimum and maximum ttl <cr> R3#tracerou 172.16.2.250 numer R3#tracerou 172.16.2.250 numeric Type escape sequence to abort. Tracing the route to 172.16.2.250 VRF info: (vrf in name/id, vrf out name/id) 1 172.16.1.1 0 msec 4 msec 0 msec 2 172.16.2.250 0 msec 4 msec 0 msec
then, shutdown R1 f0/1
R1#conf t Enter configuration commands, one per line. End with CNTL/Z. R1(config)#int f0/1 R1(config-if)#shut R1(config-if)#^Z R1# *Mar 4 10:13:01.207: %SYS-5-CONFIG_I: Configured from console by console R1# *Mar 4 10:13:02.411: %LINK-5-CHANGED: Interface FastEthernet0/1, changed state to administratively down *Mar 4 10:13:03.411: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down
R3#sh ip ro Gateway Using Interval Priority Interface 172.16.1.2 IRDP 4 18 FastEthernet0/0 Default gateway is 172.16.1.2 Host Gateway Last Use Total Uses Interface ICMP redirect cache is empty R3#ping 172.16.2.250 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 172.16.2.250, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/200/1000 ms R3#tracerou 172.16.2.250 numeric Type escape sequence to abort. Tracing the route to 172.16.2.250 VRF info: (vrf in name/id, vrf out name/id) 1 172.16.1.2 4 msec 0 msec 4 msec 2 172.16.2.250 0 msec 0 msec 4 msec
then no shut R1 f0/1
R1#conf t Enter configuration commands, one per line. End with CNTL/Z. R1(config)#int f0/1 R1(config-if)#no shut R1(config-if)# *Mar 4 10:14:57.655: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up *Mar 4 10:14:58.655: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up
failback not occured.
R3#sh ip ro Gateway Using Interval Priority Interface 172.16.1.2 IRDP 4 18 FastEthernet0/0 172.16.1.1 IRDP 7 100 FastEthernet0/0 Default gateway is 172.16.1.2 Host Gateway Last Use Total Uses Interface ICMP redirect cache is empty R3#traceroute 172.16.2.250 numeric Type escape sequence to abort. Tracing the route to 172.16.2.250 VRF info: (vrf in name/id, vrf out name/id) 1 172.16.1.2 0 msec 0 msec 4 msec 2 172.16.2.250 0 msec 0 msec 4 msec R3#ping 172.16.2.250 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 172.16.2.250, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms
then shut down all interfaces.
R1#conf t Enter configuration commands, one per line. End with CNTL/Z. R1(config)#int f0/1 R1(config-if)#shut R1(config-if)# *Mar 4 10:17:03.719: %LINK-5-CHANGED: Interface FastEthernet0/1, changed state to administratively down *Mar 4 10:17:04.719: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down
R2#conf t Enter configuration commands, one per line. End with CNTL/Z. R2(config)#int f0/1 R2(config-if)#shut R2(config-if)# *Mar 4 11:27:15.311: %LINK-5-CHANGED: Interface FastEthernet0/1, changed state to administratively down *Mar 4 11:27:16.311: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down
R3#sh ip ro Gateway Using Interval Priority Interface Default gateway is not set Host Gateway Last Use Total Uses Interface ICMP redirect cache is empty R3#ping 172.16.2.250 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 172.16.2.250, timeout is 2 seconds: ..... Success rate is 0 percent (0/5) R3#traceroute 172.16.2.250 numeric Type escape sequence to abort. Tracing the route to 172.16.2.250 VRF info: (vrf in name/id, vrf out name/id) 1 * * * 2 * * * 3 * * * 4 * *
lost ip connectivity.
no shut!!
R1#conf t Enter configuration commands, one per line. End with CNTL/Z. R1(config)# *Mar 4 10:18:47.711: %SYS-5-CONFIG_I: Configured from console by console R1(config)#int f0/1 R1(config-if)#no shut R1(config-if)# *Mar 4 10:18:59.167: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up *Mar 4 10:19:00.167: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up
R2#conf t Enter configuration commands, one per line. End with CNTL/Z. R2(config)#int f0/1 R2(config-if)#no shut R2(config-if)# *Mar 4 11:29:10.751: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up *Mar 4 11:29:11.751: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up
R1(config-if)#do sh ip irdp FastEthernet0/0 has router discovery disabled FastEthernet0/1 has router discovery enabled Advertisements will occur between every 3 and 6 seconds. Advertisements are sent with broadcasts. Advertisements are valid for 18 seconds. Default preference will be 100. Serial0/0/0 has router discovery disabled
R2(config-if)#do sh ip irdp FastEthernet0/0 has router discovery disabled FastEthernet0/1 has router discovery enabled Advertisements will occur between every 3 and 6 seconds. Advertisements are sent with broadcasts. Advertisements are valid for 18 seconds. Default preference will be 18. Serial0/0/0 has router discovery disabled
R3#sh ip ro Gateway Using Interval Priority Interface 172.16.1.1 IRDP 6 100 FastEthernet0/0 172.16.1.2 IRDP 6 18 FastEthernet0/0 Default gateway is 172.16.1.1 Host Gateway Last Use Total Uses Interface ICMP redirect cache is empty R3#ping 172.16.2.250 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 172.16.2.250, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms R3#traceroute 172.16.2.250 numeric Type escape sequence to abort. Tracing the route to 172.16.2.250 VRF info: (vrf in name/id, vrf out name/id) 1 * 172.16.1.1 0 msec 0 msec 2 172.16.2.250 4 msec 0 msec 0 msec
OK.