I recently configured a Cisco Nexus 5672UP multilayer switch and a Cisco ASR1002-X router for our MPLS core upgrade. We're running OSPF on our core network and configurations made more sense after performing numerous labs on this routing protocol.
This is me patching and configuring these devices at our core data center.
This is my OSPF lab network topology, configuration and troubleshooting during my CCNP ROUTE study.
R1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#router ospf 1
R1(config-router)#network 10.1.12.0 0.0.0.255 area 0
R1(config-router)#network 10.1.1.0 0.0.0.255 area 0
R1(config-router)#exit
R1(config)#interface loopback1
R1(config-if)#ip ospf network ?
broadcast Specify OSPF broadcast multi-access network
non-broadcast Specify OSPF NBMA network
point-to-multipoint Specify OSPF point-to-multipoint network
point-to-point Specify OSPF point-to-point network
R1(config-if)#ip ospf network point-to-point
R2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#router ospf 1
R2(config-router)#network 10.1.12.0 0.0.0.255 area 0
*Dec 13 15:01:48.131: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.1.1 on Serial0/0/0 from LOADING to FULL, Loading Done
R2(config-router)#network 10.1.2.0 0.0.0.255 area 0
R2(config-router)#exit
R2(config)#interface loopback2
R2(config-if)#ip ospf network point-to-point
R1#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
10.1.2.1 0 FULL/ - 00:00:32 10.1.12.2 Serial0/0/0
R2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
10.1.1.1 0 FULL/ - 00:00:35 10.1.12.1 Serial0/0/0
R1#show ip route
Codes: 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
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 3 subnets
C 10.1.12.0 is directly connected, Serial0/0/0
O 10.1.2.0 [110/65] via 10.1.12.2, 00:01:27, Serial0/0/0
C 10.1.1.0 is directly connected, Loopback1
R2#show ip route
Codes: 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
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 4 subnets
C 10.1.12.0 is directly connected, Serial0/0/0
C 10.1.2.0 is directly connected, Loopback2
O 10.1.1.0 [110/65] via 10.1.12.1, 00:01:41, Serial0/0/0
C 10.1.23.0 is directly connected, Serial0/0/1
R2(config)#interface serial0/0/1
R2(config-if)#ip ospf ?
<1-65535> Process ID
authentication Enable authentication
authentication-key Authentication password (key)
cost Interface cost
database-filter Filter OSPF LSA during synchronization and flooding
dead-interval Interval after which a neighbor is declared dead
demand-circuit OSPF demand circuit
flood-reduction OSPF Flood Reduction
hello-interval Time between HELLO packets
lls Link-local Signaling (LLS) support
message-digest-key Message digest authentication password (key)
mtu-ignore Ignores the MTU in DBD packets
network Network type
prefix-suppression OSPF prefix suppression
priority Router priority
resync-timeout Interval after which adjacency is reset if oob-resync is
not started
retransmit-interval Time between retransmitting lost link state
advertisements
transmit-delay Link state transmit delay
R2(config-if)#ip ospf 1 ?
area Set the OSPF area ID
R2(config-if)#ip ospf 1 area ?
<0-4294967295> OSPF area ID as a decimal value
A.B.C.D OSPF area ID in IP address format
R2(config-if)#ip ospf 1 area 23 // ANOTHER WAY OF CONFIGURING OSPF IN INTERFACE CONFIG MODE
R3(config)#interface s0/0/1
R3(config-if)#ip ospf 1 area 23
R3(config-if)#
*Dec 13 15:42:47.679: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.2.1 on Serial0/0/1 from LOADING to FULL, Loading Done
R3(config-if)#interface lo3
R3(config-if)#ip ospf 1 area 23
R3(config-if)#ip ospf network point-to-point
R2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
10.1.1.1 0 FULL/ - 00:00:30 10.1.12.1 Serial0/0/0
172.20.200.1 0 FULL/ - 00:00:36 10.1.23.3 Serial0/0/1
R1#show ip route
Codes: 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
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 5 subnets
C 10.1.12.0 is directly connected, Serial0/0/0
O IA 10.1.3.0 [110/129] via 10.1.12.2, 00:00:51, Serial0/0/0
O 10.1.2.0 [110/65] via 10.1.12.2, 00:04:44, Serial0/0/0
C 10.1.1.0 is directly connected, Loopback1
O IA 10.1.23.0 [110/128] via 10.1.12.2, 00:01:50, Serial0/0/0
R2#show ip route // NO INTER AREA ROUTE SINCE IT'S ABR
Codes: 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
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 5 subnets
C 10.1.12.0 is directly connected, Serial0/0/0
O 10.1.3.0 [110/65] via 10.1.23.3, 00:01:33, Serial0/0/1
C 10.1.2.0 is directly connected, Loopback2
O 10.1.1.0 [110/65] via 10.1.12.1, 00:02:38, Serial0/0/0
C 10.1.23.0 is directly connected, Serial0/0/1
R1#tclsh
R1(tcl)#foreach address {
+>(tcl)#10.1.1.1
+>(tcl)#10.1.2.1
+>(tcl)#10.1.3.1
+>(tcl)#10.1.12.1
+>(tcl)#10.1.12.2
+>(tcl)#10.1.23.2
+>(tcl)#10.1.23.3
+>(tcl)#172.20.200.1
+>(tcl)#} {
+>(tcl)#ping $address }
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.2.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/32 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.3.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/56/56 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.12.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/56/56 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.12.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/28 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.23.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/32 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.23.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/56/56 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.20.200.1, timeout is 2 seconds:
..... // NOT YET ADVERTISED IN OSPF
Success rate is 0 percent (0/5)
R2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#router ospf 1
R2(config-router)#area ?
<0-4294967295> OSPF area ID as a decimal value
A.B.C.D OSPF area ID in IP address format
R2(config-router)#area 23 ?
authentication Enable authentication
default-cost Set the summary default-cost of a NSSA/stub area
filter-list Filter networks between OSPF areas
nssa Specify a NSSA area
range Summarize routes matching address/mask (border routers only)
sham-link Define a sham link and its parameters
stub Specify a stub area
virtual-link Define a virtual link and its parameters
R2(config-router)#area 23 stub
R2(config-router)#
*Dec 13 15:10:02.747: %OSPF-5-ADJCHG: Process 1, Nbr 172.20.200.1 on Serial0/0/1 from FULL to DOWN, Neighbor Down: Adjacency forced to reset
R3#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#router ospf 1
R3(config-router)#area 23 stub
R3(config-router)#
*Dec 13 15:47:25.059: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.2.1 on Serial0/0/1 from FULL to DOWN, Neighbor Down: Adjacency forced to reset
R3(config-router)#
*Dec 13 15:47:31.323: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.2.1 on Serial0/0/1 from LOADING to FULL, Loading Done
R2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
10.1.1.1 0 FULL/ - 00:00:32 10.1.12.1 Serial0/0/0
172.20.200.1 0 FULL/ - 00:00:36 10.1.23.3 Serial0/0/1
R3#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
10.1.2.1 0 FULL/ - 00:00:36 10.1.23.2 Serial0/0/1
R3#show ip route
Codes: 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
Gateway of last resort is 10.1.23.2 to network 0.0.0.0
172.20.0.0/24 is subnetted, 1 subnets
C 172.20.200.0 is directly connected, Loopback20
10.0.0.0/24 is subnetted, 5 subnets
O IA 10.1.12.0 [110/128] via 10.1.23.2, 00:01:16, Serial0/0/1
C 10.1.3.0 is directly connected, Loopback3
O IA 10.1.2.0 [110/65] via 10.1.23.2, 00:01:16, Serial0/0/1
O IA 10.1.1.0 [110/129] via 10.1.23.2, 00:01:16, Serial0/0/1
C 10.1.23.0 is directly connected, Serial0/0/1
O*IA 0.0.0.0/0 [110/65] via 10.1.23.2, 00:01:16, Serial0/0/1 // STUB AREA ONLY RECEIVES A DEFAULT AND IA ROUTES
R2#show ip ospf
Routing Process "ospf 1" with ID 10.1.2.1
Start time: 00:07:26.160, Time elapsed: 00:11:51.372
Supports only single TOS(TOS0) routes
Supports opaque LSA
Supports Link-local Signaling (LLS)
Supports area transit capability
It is an area border router
Router is not originating router-LSAs with maximum metric
Initial SPF schedule delay 5000 msecs
Minimum hold time between two consecutive SPFs 10000 msecs
Maximum wait time between two consecutive SPFs 10000 msecs
Incremental-SPF disabled
Minimum LSA interval 5 secs
Minimum LSA arrival 1000 msecs
LSA group pacing timer 240 secs
Interface flood pacing timer 33 msecs
Retransmission pacing timer 66 msecs
Number of external LSA 0. Checksum Sum 0x000000
Number of opaque AS LSA 0. Checksum Sum 0x000000
Number of DCbitless external and opaque AS LSA 0
Number of DoNotAge external and opaque AS LSA 0
Number of areas in this router is 2. 1 normal 1 stub 0 nssa
Number of areas transit capable is 0
External flood list length 0
IETF NSF helper support enabled
Cisco NSF helper support enabled
Area BACKBONE(0)
Number of interfaces in this area is 2 (1 loopback)
Area has no authentication
SPF algorithm last executed 00:03:21.984 ago
SPF algorithm executed 6 times
Area ranges are
Number of LSA 4. Checksum Sum 0x01A65B
Number of opaque link LSA 0. Checksum Sum 0x000000
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
Area 23
Number of interfaces in this area is 1
It is a stub area
generates stub default route with cost 1
Area has no authentication
SPF algorithm last executed 00:02:50.368 ago
SPF algorithm executed 8 times
Area ranges are
Number of LSA 6. Checksum Sum 0x026C6C
Number of opaque link LSA 0. Checksum Sum 0x000000
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
R3#show ip route
Codes: 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
Gateway of last resort is 10.1.23.2 to network 0.0.0.0
172.20.0.0/24 is subnetted, 1 subnets
C 172.20.200.0 is directly connected, Loopback20
10.0.0.0/24 is subnetted, 5 subnets
O IA 10.1.12.0 [110/128] via 10.1.23.2, 00:04:23, Serial0/0/1
C 10.1.3.0 is directly connected, Loopback3
O IA 10.1.2.0 [110/65] via 10.1.23.2, 00:04:23, Serial0/0/1
O IA 10.1.1.0 [110/129] via 10.1.23.2, 00:04:23, Serial0/0/1
C 10.1.23.0 is directly connected, Serial0/0/1
O*IA 0.0.0.0/0 [110/65] via 10.1.23.2, 00:04:23, Serial0/0/1
R2#show ip ospf database
OSPF Router with ID (10.1.2.1) (Process ID 1)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
10.1.1.1 10.1.1.1 826 0x80000004 0x0056D6 3
10.1.2.1 10.1.2.1 617 0x80000004 0x0055D3 3
Summary Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
10.1.3.0 10.1.2.1 299 0x80000001 0x00EFEF
10.1.23.0 10.1.2.1 612 0x80000001 0x0009C3
Router Link States (Area 23)
Link ID ADV Router Age Seq# Checksum Link count
10.1.2.1 10.1.2.1 303 0x80000004 0x00298C 2
172.20.200.1 172.20.200.1 304 0x80000005 0x00B563 3
Summary Net Link States (Area 23)
Link ID ADV Router Age Seq# Checksum
0.0.0.0 10.1.2.1 330 0x80000001 0x003BF4
10.1.1.0 10.1.2.1 332 0x80000002 0x0022C0
10.1.2.0 10.1.2.1 332 0x80000003 0x00928E
10.1.12.0 10.1.2.1 332 0x80000003 0x009C3B
R2(config)#router ospf 1
R2(config-router)#area 23 stub ?
no-ext-capability Do not send domain specific capabilities into stub area
no-summary Do not send summary LSA into stub area
<cr>
R2(config-router)#area 23 stub no-summary // TO CONFIGURE TOTALLY STUBBY AREA
R3#show ip route
Codes: 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
Gateway of last resort is 10.1.23.2 to network 0.0.0.0
172.20.0.0/24 is subnetted, 1 subnets
C 172.20.200.0 is directly connected, Loopback20
10.0.0.0/24 is subnetted, 2 subnets
C 10.1.3.0 is directly connected, Loopback3
C 10.1.23.0 is directly connected, Serial0/0/1
O*IA 0.0.0.0/0 [110/65] via 10.1.23.2, 00:00:21, Serial0/0/1
R3#show ip ospf database
OSPF Router with ID (172.20.200.1) (Process ID 1)
Router Link States (Area 23)
Link ID ADV Router Age Seq# Checksum Link count
10.1.2.1 10.1.2.1 423 0x80000004 0x00298C 2
172.20.200.1 172.20.200.1 422 0x80000005 0x00B563 3
Summary Net Link States (Area 23)
Link ID ADV Router Age Seq# Checksum
0.0.0.0 10.1.2.1 72 0x80000002 0x0039F5
R2(config)#router ospf 1
R2(config-router)#no area 23 stub
*Dec 13 15:19:18.779: %OSPF-5-ADJCHG: Process 1, Nbr 172.20.200.1 on Serial0/0/1 from FULL to DOWN, Neighbor Down: Adjacency forced to reset
R2(config-router)#area 23 nssa // CONVERTS TYPE 7 TO TYPE 5 LSA
*Dec 13 15:19:28.779: %OSPF-5-ADJCHG: Process 1, Nbr 172.20.200.1 on Serial0/0/1 from DOWN to DOWN, Neighbor Down: Adjacency forced to reset
R3#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#router ospf 1
R3(config-router)#no area 23 stub
R3(config-router)#area 23 ?
authentication Enable authentication
default-cost Set the summary default-cost of a NSSA/stub area
filter-list Filter networks between OSPF areas
nssa Specify a NSSA area
range Summarize routes matching address/mask (border routers only)
sham-link Define a sham link and its parameters
stub Specify a stub area
virtual-link Define a virtual link and its parameters
R3(config-router)#area 23 nssa
R3(config-router)#
*Dec 13 15:57:21.139: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.2.1 on Serial0/0/1 from LOADING to FULL, Loading Done
R3(config-router)#redistribute ?
bgp Border Gateway Protocol (BGP)
connected Connected
eigrp Enhanced Interior Gateway Routing Protocol (EIGRP)
isis ISO IS-IS
iso-igrp IGRP for OSI networks
maximum-prefix Maximum number of prefixes redistributed to protocol
metric Metric for redistributed routes
metric-type OSPF/IS-IS exterior metric type for redistributed routes
mobile Mobile routes
odr On Demand stub Routes
ospf Open Shortest Path First (OSPF)
rip Routing Information Protocol (RIP)
route-map Route map reference
static Static routes
subnets Consider subnets for redistribution into OSPF
tag Set tag for routes redistributed into OSPF
<cr>
R3(config-router)#redistribute connected ?
metric Metric for redistributed routes
metric-type OSPF/IS-IS exterior metric type for redistributed routes
route-map Route map reference
subnets Consider subnets for redistribution into OSPF
tag Set tag for routes redistributed into OSPF
<cr>
R3(config-router)#redistribute connected subnets // TO ADVERTISE EXTERNAL AND EXACT SUBNET INTO NSSA AREA INCLUDING LOOPBACK 20
R2#show ip ospf
Routing Process "ospf 1" with ID 10.1.2.1
Start time: 00:07:26.160, Time elapsed: 00:23:04.308
Supports only single TOS(TOS0) routes
Supports opaque LSA
Supports Link-local Signaling (LLS)
Supports area transit capability
It is an area border and autonomous system boundary router
Redistributing External Routes from,
Router is not originating router-LSAs with maximum metric
Initial SPF schedule delay 5000 msecs
Minimum hold time between two consecutive SPFs 10000 msecs
Maximum wait time between two consecutive SPFs 10000 msecs
Incremental-SPF disabled
Minimum LSA interval 5 secs
Minimum LSA arrival 1000 msecs
LSA group pacing timer 240 secs
Interface flood pacing timer 33 msecs
Retransmission pacing timer 66 msecs
Number of external LSA 1. Checksum Sum 0x00CA2F
Number of opaque AS LSA 0. Checksum Sum 0x000000
Number of DCbitless external and opaque AS LSA 0
Number of DoNotAge external and opaque AS LSA 0
Number of areas in this router is 2. 1 normal 0 stub 1 nssa
Number of areas transit capable is 0
External flood list length 0
IETF NSF helper support enabled
Cisco NSF helper support enabled
Area BACKBONE(0)
Number of interfaces in this area is 2 (1 loopback)
Area has no authentication
SPF algorithm last executed 00:05:04.072 ago
SPF algorithm executed 10 times
Area ranges are
Number of LSA 4. Checksum Sum 0x01AA54
Number of opaque link LSA 0. Checksum Sum 0x000000
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
Area 23
Number of interfaces in this area is 1
It is a NSSA area
Perform type-7/type-5 LSA translation
Area has no authentication
SPF algorithm last executed 00:03:56.008 ago
SPF algorithm executed 15 times
Area ranges are
Number of LSA 6. Checksum Sum 0x025299
Number of opaque link LSA 0. Checksum Sum 0x000000
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
R2#show ip route
Codes: 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
Gateway of last resort is not set
172.20.0.0/24 is subnetted, 1 subnets
O N2 172.20.200.0 [110/20] via 10.1.23.3, 00:04:31, Serial0/0/1
10.0.0.0/24 is subnetted, 5 subnets
C 10.1.12.0 is directly connected, Serial0/0/0
O 10.1.3.0 [110/65] via 10.1.23.3, 00:04:49, Serial0/0/1
C 10.1.2.0 is directly connected, Loopback2
O 10.1.1.0 [110/65] via 10.1.12.1, 00:05:44, Serial0/0/0
C 10.1.23.0 is directly connected, Serial0/0/1
R1#show ip route
Codes: 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
Gateway of last resort is not set
172.20.0.0/24 is subnetted, 1 subnets
O E2 172.20.200.0 [110/20] via 10.1.12.2, 00:05:12, Serial0/0/0 // TRANSLATED EXTERNAL ROUTE
10.0.0.0/24 is subnetted, 5 subnets
C 10.1.12.0 is directly connected, Serial0/0/0
O IA 10.1.3.0 [110/129] via 10.1.12.2, 00:05:31, Serial0/0/0
O 10.1.2.0 [110/65] via 10.1.12.2, 00:23:26, Serial0/0/0
C 10.1.1.0 is directly connected, Loopback1
O IA 10.1.23.0 [110/128] via 10.1.12.2, 00:20:33, Serial0/0/0
R3#show ip route
Codes: 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
Gateway of last resort is not set
172.20.0.0/24 is subnetted, 1 subnets
C 172.20.200.0 is directly connected, Loopback20
10.0.0.0/24 is subnetted, 5 subnets
O IA 10.1.12.0 [110/128] via 10.1.23.2, 00:06:23, Serial0/0/1
C 10.1.3.0 is directly connected, Loopback3
O IA 10.1.2.0 [110/65] via 10.1.23.2, 00:06:23, Serial0/0/1
O IA 10.1.1.0 [110/129] via 10.1.23.2, 00:06:23, Serial0/0/1
C 10.1.23.0 is directly connected, Serial0/0/1
R2(config)#router ospf 1
R2(config-router)#area 23 nssa ?
default-information-originate Originate Type 7 default into NSSA area
no-ext-capability Do not send domain specific capabilities into
NSSA
no-redistribution No redistribution into this NSSA area
no-summary Do not send summary LSA into NSSA
translate Translate LSA
<cr>
R2(config-router)#area 23 nssa no-summary // TOTALLY STUBBY NSSA
R3#show ip route
Codes: 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
Gateway of last resort is 10.1.23.2 to network 0.0.0.0
172.20.0.0/24 is subnetted, 1 subnets
C 172.20.200.0 is directly connected, Loopback20
10.0.0.0/24 is subnetted, 2 subnets
C 10.1.3.0 is directly connected, Loopback3
C 10.1.23.0 is directly connected, Serial0/0/1
O*IA 0.0.0.0/0 [110/65] via 10.1.23.2, 00:00:47, Serial0/0/1
R2#show ip ospf database
OSPF Router with ID (10.1.2.1) (Process ID 1)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
10.1.1.1 10.1.1.1 1628 0x80000004 0x0056D6 3
10.1.2.1 10.1.2.1 566 0x80000005 0x0059CC 3
Summary Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
10.1.3.0 10.1.2.1 512 0x80000001 0x00EFEF
10.1.23.0 10.1.2.1 1415 0x80000001 0x0009C3
Router Link States (Area 23)
Link ID ADV Router Age Seq# Checksum Link count
10.1.2.1 10.1.2.1 516 0x80000007 0x00B0F7 2
172.20.200.1 172.20.200.1 500 0x80000008 0x003DCE 3
Summary Net Link States (Area 23)
Link ID ADV Router Age Seq# Checksum
0.0.0.0 10.1.2.1 78 0x80000001 0x00C265
Type-7 AS External Link States (Area 23)
Link ID ADV Router Age Seq# Checksum Tag
172.20.200.0 172.20.200.1 501 0x80000001 0x0076FC 0
Type-5 AS External Link States
Link ID ADV Router Age Seq# Checksum Tag
172.20.200.0 10.1.2.1 495 0x80000001 0x00CA2F 0
R2(config)#interface serial0/0/1
R2(config-if)#ip ospf ?
<1-65535> Process ID
authentication Enable authentication
authentication-key Authentication password (key)
cost Interface cost
database-filter Filter OSPF LSA during synchronization and flooding
dead-interval Interval after which a neighbor is declared dead
demand-circuit OSPF demand circuit
flood-reduction OSPF Flood Reduction
hello-interval Time between HELLO packets
lls Link-local Signaling (LLS) support
message-digest-key Message digest authentication password (key)
mtu-ignore Ignores the MTU in DBD packets
network Network type
prefix-suppression OSPF prefix suppression
priority Router priority
resync-timeout Interval after which adjacency is reset if oob-resync is
not started
retransmit-interval Time between retransmitting lost link state
advertisements
transmit-delay Link state transmit delay
R2(config-if)#ip ospf authentication
R2(config-if)#ip ospf authentication-key ?
<0-7> Encryption type (0 for not yet encrypted, 7 for proprietary)
LINE The OSPF password (key) (maximum 8 characters)
R2(config-if)#ip ospf authentication-key cisco
R3#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#interface serial0/0/1
R3(config-if)#ip ospf authentication
*Dec 13 16:07:45.779: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.2.1 on Serial0/0/1 from FULL to DOWN, Neighbor Down: Dead timer expired
R3(config-if)#ip ospf authentication-key cisco
R3(config-if)#
*Dec 13 16:07:58.435: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.2.1 on Serial0/0/1 from LOADING to FULL, Loading Done
R3#show ip ospf interface s0/0/1
Serial0/0/1 is up, line protocol is up
Internet Address 10.1.23.3/24, Area 23
Process ID 1, Router ID 172.20.200.1, Network Type POINT_TO_POINT, Cost: 64
Enabled by interface config, including secondary ip addresses
Transmit Delay is 1 sec, State POINT_TO_POINT
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Hello due in 00:00:04
Supports Link-local Signaling (LLS)
Cisco NSF helper support enabled
IETF NSF helper support enabled
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 10.1.2.1
Suppress hello for 0 neighbor(s)
Simple password authentication enabled
R1(config)#interface s0/0/0
R1(config-if)#ip ospf authentication ?
message-digest Use message-digest authentication
null Use no authentication
<cr>
R1(config-if)#ip ospf authentication message-digest
R1(config-if)#ip ospf ?
<1-65535> Process ID
authentication Enable authentication
authentication-key Authentication password (key)
cost Interface cost
database-filter Filter OSPF LSA during synchronization and flooding
dead-interval Interval after which a neighbor is declared dead
demand-circuit OSPF demand circuit
flood-reduction OSPF Flood Reduction
hello-interval Time between HELLO packets
lls Link-local Signaling (LLS) support
message-digest-key Message digest authentication password (key)
mtu-ignore Ignores the MTU in DBD packets
network Network type
prefix-suppression OSPF prefix suppression
priority Router priority
resync-timeout Interval after which adjacency is reset if oob-resync is
not started
retransmit-interval Time between retransmitting lost link state
advertisements
transmit-delay Link state transmit delay
R1(config-if)#ip ospf message-digest-key ?
<1-255> Key ID
R1(config-if)#ip ospf message-digest-key 1 ?
md5 Use MD5 algorithm
R1(config-if)#ip ospf message-digest-key 1 md5 ?
<0-7> Encryption type (0 for not yet encrypted, 7 for proprietary)
LINE The OSPF password (key) (maximum 16 characters)
R1(config-if)#ip ospf message-digest-key 1 md5 cisco
R1(config-if)#
*Dec 13 16:51:46.895: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.2.1 on Serial0/0/0 from FULL to DOWN, Neighbor Down: Dead timer expired
R2(config)#interface s0/0/0
R2(config-if)#ip ospf authentication message-digest
R2(config-if)#ip ospf message-digest-key 1 md5 cisco
R2(config-if)#
*Dec 13 15:35:12.019: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.1.1 on Serial0/0/0 from LOADING to FULL, Loading Done
R2#show ip ospf interface s0/0/0
Serial0/0/0 is up, line protocol is up
Internet Address 10.1.12.2/24, Area 0
Process ID 1, Router ID 10.1.2.1, Network Type POINT_TO_POINT, Cost: 64
Transmit Delay is 1 sec, State POINT_TO_POINT
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Hello due in 00:00:03
Supports Link-local Signaling (LLS)
Cisco NSF helper support enabled
IETF NSF helper support enabled
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 10.1.1.1
Suppress hello for 0 neighbor(s)
Message digest authentication enabled
Youngest key id is 1
R1#tclsh
R1(tcl)#foreach address {
+>(tcl)#10.1.1.1
+>(tcl)#10.1.2.1
+>(tcl)#10.1.3.1
+>(tcl)#10.1.12.1
+>(tcl)#10.1.12.2
+>(tcl)#10.1.23.2
+>(tcl)#10.1.23.3
+>(tcl)#172.20.200.1
+>(tcl)#} {
+>(tcl)#ping $address }
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.2.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/28 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.3.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/56/56 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.12.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/56/60 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.12.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/28 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.23.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/32 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.23.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/56/56 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.20.200.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/56/56 ms
This is me patching and configuring these devices at our core data center.
This is my OSPF lab network topology, configuration and troubleshooting during my CCNP ROUTE study.
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#router ospf 1
R1(config-router)#network 10.1.12.0 0.0.0.255 area 0
R1(config-router)#network 10.1.1.0 0.0.0.255 area 0
R1(config-router)#exit
R1(config)#interface loopback1
R1(config-if)#ip ospf network ?
broadcast Specify OSPF broadcast multi-access network
non-broadcast Specify OSPF NBMA network
point-to-multipoint Specify OSPF point-to-multipoint network
point-to-point Specify OSPF point-to-point network
R1(config-if)#ip ospf network point-to-point
R2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#router ospf 1
R2(config-router)#network 10.1.12.0 0.0.0.255 area 0
*Dec 13 15:01:48.131: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.1.1 on Serial0/0/0 from LOADING to FULL, Loading Done
R2(config-router)#network 10.1.2.0 0.0.0.255 area 0
R2(config-router)#exit
R2(config)#interface loopback2
R2(config-if)#ip ospf network point-to-point
R1#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
10.1.2.1 0 FULL/ - 00:00:32 10.1.12.2 Serial0/0/0
R2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
10.1.1.1 0 FULL/ - 00:00:35 10.1.12.1 Serial0/0/0
R1#show ip route
Codes: 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
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 3 subnets
C 10.1.12.0 is directly connected, Serial0/0/0
O 10.1.2.0 [110/65] via 10.1.12.2, 00:01:27, Serial0/0/0
C 10.1.1.0 is directly connected, Loopback1
R2#show ip route
Codes: 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
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 4 subnets
C 10.1.12.0 is directly connected, Serial0/0/0
C 10.1.2.0 is directly connected, Loopback2
O 10.1.1.0 [110/65] via 10.1.12.1, 00:01:41, Serial0/0/0
C 10.1.23.0 is directly connected, Serial0/0/1
R2(config)#interface serial0/0/1
R2(config-if)#ip ospf ?
<1-65535> Process ID
authentication Enable authentication
authentication-key Authentication password (key)
cost Interface cost
database-filter Filter OSPF LSA during synchronization and flooding
dead-interval Interval after which a neighbor is declared dead
demand-circuit OSPF demand circuit
flood-reduction OSPF Flood Reduction
hello-interval Time between HELLO packets
lls Link-local Signaling (LLS) support
message-digest-key Message digest authentication password (key)
mtu-ignore Ignores the MTU in DBD packets
network Network type
prefix-suppression OSPF prefix suppression
priority Router priority
resync-timeout Interval after which adjacency is reset if oob-resync is
not started
retransmit-interval Time between retransmitting lost link state
advertisements
transmit-delay Link state transmit delay
R2(config-if)#ip ospf 1 ?
area Set the OSPF area ID
R2(config-if)#ip ospf 1 area ?
<0-4294967295> OSPF area ID as a decimal value
A.B.C.D OSPF area ID in IP address format
R2(config-if)#ip ospf 1 area 23 // ANOTHER WAY OF CONFIGURING OSPF IN INTERFACE CONFIG MODE
R3(config)#interface s0/0/1
R3(config-if)#ip ospf 1 area 23
R3(config-if)#
*Dec 13 15:42:47.679: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.2.1 on Serial0/0/1 from LOADING to FULL, Loading Done
R3(config-if)#interface lo3
R3(config-if)#ip ospf 1 area 23
R3(config-if)#ip ospf network point-to-point
R2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
10.1.1.1 0 FULL/ - 00:00:30 10.1.12.1 Serial0/0/0
172.20.200.1 0 FULL/ - 00:00:36 10.1.23.3 Serial0/0/1
R1#show ip route
Codes: 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
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 5 subnets
C 10.1.12.0 is directly connected, Serial0/0/0
O IA 10.1.3.0 [110/129] via 10.1.12.2, 00:00:51, Serial0/0/0
O 10.1.2.0 [110/65] via 10.1.12.2, 00:04:44, Serial0/0/0
C 10.1.1.0 is directly connected, Loopback1
O IA 10.1.23.0 [110/128] via 10.1.12.2, 00:01:50, Serial0/0/0
R2#show ip route // NO INTER AREA ROUTE SINCE IT'S ABR
Codes: 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
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 5 subnets
C 10.1.12.0 is directly connected, Serial0/0/0
O 10.1.3.0 [110/65] via 10.1.23.3, 00:01:33, Serial0/0/1
C 10.1.2.0 is directly connected, Loopback2
O 10.1.1.0 [110/65] via 10.1.12.1, 00:02:38, Serial0/0/0
C 10.1.23.0 is directly connected, Serial0/0/1
R1#tclsh
R1(tcl)#foreach address {
+>(tcl)#10.1.1.1
+>(tcl)#10.1.2.1
+>(tcl)#10.1.3.1
+>(tcl)#10.1.12.1
+>(tcl)#10.1.12.2
+>(tcl)#10.1.23.2
+>(tcl)#10.1.23.3
+>(tcl)#172.20.200.1
+>(tcl)#} {
+>(tcl)#ping $address }
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.2.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/32 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.3.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/56/56 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.12.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/56/56 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.12.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/28 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.23.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/32 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.23.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/56/56 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.20.200.1, timeout is 2 seconds:
..... // NOT YET ADVERTISED IN OSPF
Success rate is 0 percent (0/5)
R2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#router ospf 1
R2(config-router)#area ?
<0-4294967295> OSPF area ID as a decimal value
A.B.C.D OSPF area ID in IP address format
R2(config-router)#area 23 ?
authentication Enable authentication
default-cost Set the summary default-cost of a NSSA/stub area
filter-list Filter networks between OSPF areas
nssa Specify a NSSA area
range Summarize routes matching address/mask (border routers only)
sham-link Define a sham link and its parameters
stub Specify a stub area
virtual-link Define a virtual link and its parameters
R2(config-router)#area 23 stub
R2(config-router)#
*Dec 13 15:10:02.747: %OSPF-5-ADJCHG: Process 1, Nbr 172.20.200.1 on Serial0/0/1 from FULL to DOWN, Neighbor Down: Adjacency forced to reset
R3#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#router ospf 1
R3(config-router)#area 23 stub
R3(config-router)#
*Dec 13 15:47:25.059: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.2.1 on Serial0/0/1 from FULL to DOWN, Neighbor Down: Adjacency forced to reset
R3(config-router)#
*Dec 13 15:47:31.323: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.2.1 on Serial0/0/1 from LOADING to FULL, Loading Done
R2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
10.1.1.1 0 FULL/ - 00:00:32 10.1.12.1 Serial0/0/0
172.20.200.1 0 FULL/ - 00:00:36 10.1.23.3 Serial0/0/1
R3#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
10.1.2.1 0 FULL/ - 00:00:36 10.1.23.2 Serial0/0/1
R3#show ip route
Codes: 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
Gateway of last resort is 10.1.23.2 to network 0.0.0.0
172.20.0.0/24 is subnetted, 1 subnets
C 172.20.200.0 is directly connected, Loopback20
10.0.0.0/24 is subnetted, 5 subnets
O IA 10.1.12.0 [110/128] via 10.1.23.2, 00:01:16, Serial0/0/1
C 10.1.3.0 is directly connected, Loopback3
O IA 10.1.2.0 [110/65] via 10.1.23.2, 00:01:16, Serial0/0/1
O IA 10.1.1.0 [110/129] via 10.1.23.2, 00:01:16, Serial0/0/1
C 10.1.23.0 is directly connected, Serial0/0/1
O*IA 0.0.0.0/0 [110/65] via 10.1.23.2, 00:01:16, Serial0/0/1 // STUB AREA ONLY RECEIVES A DEFAULT AND IA ROUTES
R2#show ip ospf
Routing Process "ospf 1" with ID 10.1.2.1
Start time: 00:07:26.160, Time elapsed: 00:11:51.372
Supports only single TOS(TOS0) routes
Supports opaque LSA
Supports Link-local Signaling (LLS)
Supports area transit capability
It is an area border router
Router is not originating router-LSAs with maximum metric
Initial SPF schedule delay 5000 msecs
Minimum hold time between two consecutive SPFs 10000 msecs
Maximum wait time between two consecutive SPFs 10000 msecs
Incremental-SPF disabled
Minimum LSA interval 5 secs
Minimum LSA arrival 1000 msecs
LSA group pacing timer 240 secs
Interface flood pacing timer 33 msecs
Retransmission pacing timer 66 msecs
Number of external LSA 0. Checksum Sum 0x000000
Number of opaque AS LSA 0. Checksum Sum 0x000000
Number of DCbitless external and opaque AS LSA 0
Number of DoNotAge external and opaque AS LSA 0
Number of areas in this router is 2. 1 normal 1 stub 0 nssa
Number of areas transit capable is 0
External flood list length 0
IETF NSF helper support enabled
Cisco NSF helper support enabled
Area BACKBONE(0)
Number of interfaces in this area is 2 (1 loopback)
Area has no authentication
SPF algorithm last executed 00:03:21.984 ago
SPF algorithm executed 6 times
Area ranges are
Number of LSA 4. Checksum Sum 0x01A65B
Number of opaque link LSA 0. Checksum Sum 0x000000
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
Area 23
Number of interfaces in this area is 1
It is a stub area
generates stub default route with cost 1
Area has no authentication
SPF algorithm last executed 00:02:50.368 ago
SPF algorithm executed 8 times
Area ranges are
Number of LSA 6. Checksum Sum 0x026C6C
Number of opaque link LSA 0. Checksum Sum 0x000000
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
R3#show ip route
Codes: 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
Gateway of last resort is 10.1.23.2 to network 0.0.0.0
172.20.0.0/24 is subnetted, 1 subnets
C 172.20.200.0 is directly connected, Loopback20
10.0.0.0/24 is subnetted, 5 subnets
O IA 10.1.12.0 [110/128] via 10.1.23.2, 00:04:23, Serial0/0/1
C 10.1.3.0 is directly connected, Loopback3
O IA 10.1.2.0 [110/65] via 10.1.23.2, 00:04:23, Serial0/0/1
O IA 10.1.1.0 [110/129] via 10.1.23.2, 00:04:23, Serial0/0/1
C 10.1.23.0 is directly connected, Serial0/0/1
O*IA 0.0.0.0/0 [110/65] via 10.1.23.2, 00:04:23, Serial0/0/1
R2#show ip ospf database
OSPF Router with ID (10.1.2.1) (Process ID 1)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
10.1.1.1 10.1.1.1 826 0x80000004 0x0056D6 3
10.1.2.1 10.1.2.1 617 0x80000004 0x0055D3 3
Summary Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
10.1.3.0 10.1.2.1 299 0x80000001 0x00EFEF
10.1.23.0 10.1.2.1 612 0x80000001 0x0009C3
Router Link States (Area 23)
Link ID ADV Router Age Seq# Checksum Link count
10.1.2.1 10.1.2.1 303 0x80000004 0x00298C 2
172.20.200.1 172.20.200.1 304 0x80000005 0x00B563 3
Summary Net Link States (Area 23)
Link ID ADV Router Age Seq# Checksum
0.0.0.0 10.1.2.1 330 0x80000001 0x003BF4
10.1.1.0 10.1.2.1 332 0x80000002 0x0022C0
10.1.2.0 10.1.2.1 332 0x80000003 0x00928E
10.1.12.0 10.1.2.1 332 0x80000003 0x009C3B
R2(config)#router ospf 1
R2(config-router)#area 23 stub ?
no-ext-capability Do not send domain specific capabilities into stub area
no-summary Do not send summary LSA into stub area
<cr>
R2(config-router)#area 23 stub no-summary // TO CONFIGURE TOTALLY STUBBY AREA
R3#show ip route
Codes: 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
Gateway of last resort is 10.1.23.2 to network 0.0.0.0
172.20.0.0/24 is subnetted, 1 subnets
C 172.20.200.0 is directly connected, Loopback20
10.0.0.0/24 is subnetted, 2 subnets
C 10.1.3.0 is directly connected, Loopback3
C 10.1.23.0 is directly connected, Serial0/0/1
O*IA 0.0.0.0/0 [110/65] via 10.1.23.2, 00:00:21, Serial0/0/1
R3#show ip ospf database
OSPF Router with ID (172.20.200.1) (Process ID 1)
Router Link States (Area 23)
Link ID ADV Router Age Seq# Checksum Link count
10.1.2.1 10.1.2.1 423 0x80000004 0x00298C 2
172.20.200.1 172.20.200.1 422 0x80000005 0x00B563 3
Summary Net Link States (Area 23)
Link ID ADV Router Age Seq# Checksum
0.0.0.0 10.1.2.1 72 0x80000002 0x0039F5
R2(config)#router ospf 1
R2(config-router)#no area 23 stub
*Dec 13 15:19:18.779: %OSPF-5-ADJCHG: Process 1, Nbr 172.20.200.1 on Serial0/0/1 from FULL to DOWN, Neighbor Down: Adjacency forced to reset
R2(config-router)#area 23 nssa // CONVERTS TYPE 7 TO TYPE 5 LSA
*Dec 13 15:19:28.779: %OSPF-5-ADJCHG: Process 1, Nbr 172.20.200.1 on Serial0/0/1 from DOWN to DOWN, Neighbor Down: Adjacency forced to reset
R3#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#router ospf 1
R3(config-router)#no area 23 stub
R3(config-router)#area 23 ?
authentication Enable authentication
default-cost Set the summary default-cost of a NSSA/stub area
filter-list Filter networks between OSPF areas
nssa Specify a NSSA area
range Summarize routes matching address/mask (border routers only)
sham-link Define a sham link and its parameters
stub Specify a stub area
virtual-link Define a virtual link and its parameters
R3(config-router)#area 23 nssa
R3(config-router)#
*Dec 13 15:57:21.139: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.2.1 on Serial0/0/1 from LOADING to FULL, Loading Done
R3(config-router)#redistribute ?
bgp Border Gateway Protocol (BGP)
connected Connected
eigrp Enhanced Interior Gateway Routing Protocol (EIGRP)
isis ISO IS-IS
iso-igrp IGRP for OSI networks
maximum-prefix Maximum number of prefixes redistributed to protocol
metric Metric for redistributed routes
metric-type OSPF/IS-IS exterior metric type for redistributed routes
mobile Mobile routes
odr On Demand stub Routes
ospf Open Shortest Path First (OSPF)
rip Routing Information Protocol (RIP)
route-map Route map reference
static Static routes
subnets Consider subnets for redistribution into OSPF
tag Set tag for routes redistributed into OSPF
<cr>
R3(config-router)#redistribute connected ?
metric Metric for redistributed routes
metric-type OSPF/IS-IS exterior metric type for redistributed routes
route-map Route map reference
subnets Consider subnets for redistribution into OSPF
tag Set tag for routes redistributed into OSPF
<cr>
R3(config-router)#redistribute connected subnets // TO ADVERTISE EXTERNAL AND EXACT SUBNET INTO NSSA AREA INCLUDING LOOPBACK 20
R2#show ip ospf
Routing Process "ospf 1" with ID 10.1.2.1
Start time: 00:07:26.160, Time elapsed: 00:23:04.308
Supports only single TOS(TOS0) routes
Supports opaque LSA
Supports Link-local Signaling (LLS)
Supports area transit capability
It is an area border and autonomous system boundary router
Redistributing External Routes from,
Router is not originating router-LSAs with maximum metric
Initial SPF schedule delay 5000 msecs
Minimum hold time between two consecutive SPFs 10000 msecs
Maximum wait time between two consecutive SPFs 10000 msecs
Incremental-SPF disabled
Minimum LSA interval 5 secs
Minimum LSA arrival 1000 msecs
LSA group pacing timer 240 secs
Interface flood pacing timer 33 msecs
Retransmission pacing timer 66 msecs
Number of external LSA 1. Checksum Sum 0x00CA2F
Number of opaque AS LSA 0. Checksum Sum 0x000000
Number of DCbitless external and opaque AS LSA 0
Number of DoNotAge external and opaque AS LSA 0
Number of areas in this router is 2. 1 normal 0 stub 1 nssa
Number of areas transit capable is 0
External flood list length 0
IETF NSF helper support enabled
Cisco NSF helper support enabled
Area BACKBONE(0)
Number of interfaces in this area is 2 (1 loopback)
Area has no authentication
SPF algorithm last executed 00:05:04.072 ago
SPF algorithm executed 10 times
Area ranges are
Number of LSA 4. Checksum Sum 0x01AA54
Number of opaque link LSA 0. Checksum Sum 0x000000
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
Area 23
Number of interfaces in this area is 1
It is a NSSA area
Perform type-7/type-5 LSA translation
Area has no authentication
SPF algorithm last executed 00:03:56.008 ago
SPF algorithm executed 15 times
Area ranges are
Number of LSA 6. Checksum Sum 0x025299
Number of opaque link LSA 0. Checksum Sum 0x000000
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
R2#show ip route
Codes: 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
Gateway of last resort is not set
172.20.0.0/24 is subnetted, 1 subnets
O N2 172.20.200.0 [110/20] via 10.1.23.3, 00:04:31, Serial0/0/1
10.0.0.0/24 is subnetted, 5 subnets
C 10.1.12.0 is directly connected, Serial0/0/0
O 10.1.3.0 [110/65] via 10.1.23.3, 00:04:49, Serial0/0/1
C 10.1.2.0 is directly connected, Loopback2
O 10.1.1.0 [110/65] via 10.1.12.1, 00:05:44, Serial0/0/0
C 10.1.23.0 is directly connected, Serial0/0/1
R1#show ip route
Codes: 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
Gateway of last resort is not set
172.20.0.0/24 is subnetted, 1 subnets
O E2 172.20.200.0 [110/20] via 10.1.12.2, 00:05:12, Serial0/0/0 // TRANSLATED EXTERNAL ROUTE
10.0.0.0/24 is subnetted, 5 subnets
C 10.1.12.0 is directly connected, Serial0/0/0
O IA 10.1.3.0 [110/129] via 10.1.12.2, 00:05:31, Serial0/0/0
O 10.1.2.0 [110/65] via 10.1.12.2, 00:23:26, Serial0/0/0
C 10.1.1.0 is directly connected, Loopback1
O IA 10.1.23.0 [110/128] via 10.1.12.2, 00:20:33, Serial0/0/0
R3#show ip route
Codes: 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
Gateway of last resort is not set
172.20.0.0/24 is subnetted, 1 subnets
C 172.20.200.0 is directly connected, Loopback20
10.0.0.0/24 is subnetted, 5 subnets
O IA 10.1.12.0 [110/128] via 10.1.23.2, 00:06:23, Serial0/0/1
C 10.1.3.0 is directly connected, Loopback3
O IA 10.1.2.0 [110/65] via 10.1.23.2, 00:06:23, Serial0/0/1
O IA 10.1.1.0 [110/129] via 10.1.23.2, 00:06:23, Serial0/0/1
C 10.1.23.0 is directly connected, Serial0/0/1
R2(config)#router ospf 1
R2(config-router)#area 23 nssa ?
default-information-originate Originate Type 7 default into NSSA area
no-ext-capability Do not send domain specific capabilities into
NSSA
no-redistribution No redistribution into this NSSA area
no-summary Do not send summary LSA into NSSA
translate Translate LSA
<cr>
R2(config-router)#area 23 nssa no-summary // TOTALLY STUBBY NSSA
R3#show ip route
Codes: 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
Gateway of last resort is 10.1.23.2 to network 0.0.0.0
172.20.0.0/24 is subnetted, 1 subnets
C 172.20.200.0 is directly connected, Loopback20
10.0.0.0/24 is subnetted, 2 subnets
C 10.1.3.0 is directly connected, Loopback3
C 10.1.23.0 is directly connected, Serial0/0/1
O*IA 0.0.0.0/0 [110/65] via 10.1.23.2, 00:00:47, Serial0/0/1
R2#show ip ospf database
OSPF Router with ID (10.1.2.1) (Process ID 1)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
10.1.1.1 10.1.1.1 1628 0x80000004 0x0056D6 3
10.1.2.1 10.1.2.1 566 0x80000005 0x0059CC 3
Summary Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
10.1.3.0 10.1.2.1 512 0x80000001 0x00EFEF
10.1.23.0 10.1.2.1 1415 0x80000001 0x0009C3
Router Link States (Area 23)
Link ID ADV Router Age Seq# Checksum Link count
10.1.2.1 10.1.2.1 516 0x80000007 0x00B0F7 2
172.20.200.1 172.20.200.1 500 0x80000008 0x003DCE 3
Summary Net Link States (Area 23)
Link ID ADV Router Age Seq# Checksum
0.0.0.0 10.1.2.1 78 0x80000001 0x00C265
Type-7 AS External Link States (Area 23)
Link ID ADV Router Age Seq# Checksum Tag
172.20.200.0 172.20.200.1 501 0x80000001 0x0076FC 0
Type-5 AS External Link States
Link ID ADV Router Age Seq# Checksum Tag
172.20.200.0 10.1.2.1 495 0x80000001 0x00CA2F 0
R2(config)#interface serial0/0/1
R2(config-if)#ip ospf ?
<1-65535> Process ID
authentication Enable authentication
authentication-key Authentication password (key)
cost Interface cost
database-filter Filter OSPF LSA during synchronization and flooding
dead-interval Interval after which a neighbor is declared dead
demand-circuit OSPF demand circuit
flood-reduction OSPF Flood Reduction
hello-interval Time between HELLO packets
lls Link-local Signaling (LLS) support
message-digest-key Message digest authentication password (key)
mtu-ignore Ignores the MTU in DBD packets
network Network type
prefix-suppression OSPF prefix suppression
priority Router priority
resync-timeout Interval after which adjacency is reset if oob-resync is
not started
retransmit-interval Time between retransmitting lost link state
advertisements
transmit-delay Link state transmit delay
R2(config-if)#ip ospf authentication
R2(config-if)#ip ospf authentication-key ?
<0-7> Encryption type (0 for not yet encrypted, 7 for proprietary)
LINE The OSPF password (key) (maximum 8 characters)
R2(config-if)#ip ospf authentication-key cisco
R3#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#interface serial0/0/1
R3(config-if)#ip ospf authentication
*Dec 13 16:07:45.779: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.2.1 on Serial0/0/1 from FULL to DOWN, Neighbor Down: Dead timer expired
R3(config-if)#ip ospf authentication-key cisco
R3(config-if)#
*Dec 13 16:07:58.435: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.2.1 on Serial0/0/1 from LOADING to FULL, Loading Done
R3#show ip ospf interface s0/0/1
Serial0/0/1 is up, line protocol is up
Internet Address 10.1.23.3/24, Area 23
Process ID 1, Router ID 172.20.200.1, Network Type POINT_TO_POINT, Cost: 64
Enabled by interface config, including secondary ip addresses
Transmit Delay is 1 sec, State POINT_TO_POINT
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Hello due in 00:00:04
Supports Link-local Signaling (LLS)
Cisco NSF helper support enabled
IETF NSF helper support enabled
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 10.1.2.1
Suppress hello for 0 neighbor(s)
Simple password authentication enabled
R1(config)#interface s0/0/0
R1(config-if)#ip ospf authentication ?
message-digest Use message-digest authentication
null Use no authentication
<cr>
R1(config-if)#ip ospf authentication message-digest
R1(config-if)#ip ospf ?
<1-65535> Process ID
authentication Enable authentication
authentication-key Authentication password (key)
cost Interface cost
database-filter Filter OSPF LSA during synchronization and flooding
dead-interval Interval after which a neighbor is declared dead
demand-circuit OSPF demand circuit
flood-reduction OSPF Flood Reduction
hello-interval Time between HELLO packets
lls Link-local Signaling (LLS) support
message-digest-key Message digest authentication password (key)
mtu-ignore Ignores the MTU in DBD packets
network Network type
prefix-suppression OSPF prefix suppression
priority Router priority
resync-timeout Interval after which adjacency is reset if oob-resync is
not started
retransmit-interval Time between retransmitting lost link state
advertisements
transmit-delay Link state transmit delay
R1(config-if)#ip ospf message-digest-key ?
<1-255> Key ID
R1(config-if)#ip ospf message-digest-key 1 ?
md5 Use MD5 algorithm
R1(config-if)#ip ospf message-digest-key 1 md5 ?
<0-7> Encryption type (0 for not yet encrypted, 7 for proprietary)
LINE The OSPF password (key) (maximum 16 characters)
R1(config-if)#ip ospf message-digest-key 1 md5 cisco
R1(config-if)#
*Dec 13 16:51:46.895: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.2.1 on Serial0/0/0 from FULL to DOWN, Neighbor Down: Dead timer expired
R2(config)#interface s0/0/0
R2(config-if)#ip ospf authentication message-digest
R2(config-if)#ip ospf message-digest-key 1 md5 cisco
R2(config-if)#
*Dec 13 15:35:12.019: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.1.1 on Serial0/0/0 from LOADING to FULL, Loading Done
R2#show ip ospf interface s0/0/0
Serial0/0/0 is up, line protocol is up
Internet Address 10.1.12.2/24, Area 0
Process ID 1, Router ID 10.1.2.1, Network Type POINT_TO_POINT, Cost: 64
Transmit Delay is 1 sec, State POINT_TO_POINT
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Hello due in 00:00:03
Supports Link-local Signaling (LLS)
Cisco NSF helper support enabled
IETF NSF helper support enabled
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 10.1.1.1
Suppress hello for 0 neighbor(s)
Message digest authentication enabled
Youngest key id is 1
R1#tclsh
R1(tcl)#foreach address {
+>(tcl)#10.1.1.1
+>(tcl)#10.1.2.1
+>(tcl)#10.1.3.1
+>(tcl)#10.1.12.1
+>(tcl)#10.1.12.2
+>(tcl)#10.1.23.2
+>(tcl)#10.1.23.3
+>(tcl)#172.20.200.1
+>(tcl)#} {
+>(tcl)#ping $address }
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.2.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/28 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.3.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/56/56 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.12.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/56/60 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.12.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/28 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.23.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/32 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.23.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/56/56 ms
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.20.200.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/56/56 ms
