OSPF Troubleshooting (v2/v3)

A network engineer is troubleshooting an OSPFv2 adjacency issue between two directly connected routers, R1 and R2, both running IOS-XE. The link is a point-to-point Ethernet link. The engineer issues 'show ip ospf neighbor' on R1 and sees no neighbors. 'show ip ospf interface GigabitEthernet0/0' on R1 shows 'Network Type BROADCAST', but the link is actually a point-to-point link. Both routers have 'ip ospf 1 area 0' configured on the interface. What is the most likely cause of the adjacency not forming?

A network engineer is troubleshooting OSPFv3 on a dual-stack network. Routers R1 and R2 are connected via a serial link. Both routers have OSPFv3 configured for IPv6. The engineer runs 'show ipv6 ospf neighbor' on R1 and sees R2 as FULL/DR. However, R1 cannot ping the IPv6 address of R2's loopback interface. 'show ipv6 route ospf' on R1 does not show any OSPF routes. What is the most likely cause?

A network engineer is troubleshooting OSPFv2 route redistribution. R1 is an ASBR redistributing static routes into OSPF. R2, an internal router, receives the redistributed routes but they appear as O E2 routes. However, R1 also has a directly connected network 10.1.1.0/24 that is not being advertised as an OSPF route. 'show ip ospf database external' on R2 shows the redistributed static routes but not the connected network. What is the most likely cause?

A network engineer is troubleshooting an OSPFv2 adjacency issue between two routers across a Frame Relay network. R1 and R2 are connected via a point-to-point subinterface. The engineer configures 'ip ospf network point-to-point' on both subinterfaces. However, the adjacency does not form. 'show ip ospf interface' on R1 shows the interface is up and OSPF is enabled, but no neighbors are seen. What is the most likely cause?

A network engineer is troubleshooting an OSPFv3 issue where a router R1 is not learning routes from a neighbor R2. The adjacency is FULL, but 'show ipv6 route ospf' on R1 shows only a default route. R2 is an ASBR redistributing connected routes into OSPFv3. 'show ipv6 ospf database external' on R1 shows the external routes, but they are not installed in the routing table. What is the most likely cause?

A network engineer is troubleshooting an OSPFv2 route flapping issue. The router R1 is learning a route to 192.168.1.0/24 via two different paths: one through R2 and one through R3. The route is flapping between the two paths every few seconds. 'show ip ospf interface' shows that both interfaces are stable. What is the most likely cause?

A network engineer is troubleshooting an OSPFv2 adjacency issue between two routers connected via a VLAN trunk. R1 and R2 are in different VLANs but are connected through a Layer 2 switch. The engineer has configured 'ip ospf 1 area 0' on the subinterfaces. The adjacency forms but is stuck in INIT state. What is the most likely cause?

A network engineer is troubleshooting an OSPFv2 issue where a router R1 is not receiving a specific route for 10.0.0.0/8 from a neighbor R2. The adjacency is FULL, and 'show ip ospf database' on R1 shows the LSA for 10.0.0.0/8 as a type 5 LSA. However, the route is not in the routing table. 'show ip route 10.0.0.0' shows no route. What is the most likely cause?

A network engineer is troubleshooting an OSPFv3 adjacency issue between two routers over an IPv6-only link. The engineer configures OSPFv3 on both routers and sees that the adjacency is stuck in EXSTART state. 'debug ipv6 ospf packet' shows that the routers are exchanging DBD packets but not progressing. What is the most likely cause?

A network engineer runs the following command on Router R1: R1# show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.1.1.2 1 FULL/DROTHER 00:00:35 192.168.12.2 GigabitEthernet0/0 10.1.1.3 1 FULL/DR 00:00:32 192.168.13.3 GigabitEthernet0/1 Based on this output, which statement is correct?

A network engineer runs the following command on Router R1: R1# show ip ospf database OSPF Router with ID (10.1.1.1) (Process ID 1) Router Link States (Area 0) Link ID ADV Router Age Seq# Checksum Link count 10.1.1.1 10.1.1.1 120 0x80000002 0x00A1B2 3 10.1.1.2 10.1.1.2 200 0x80000001 0x00B2C3 2 10.1.1.3 10.1.1.3 150 0x80000003 0x00C3D4 4 Net Link States (Area 0) Link ID ADV Router Age Seq# Checksum 192.168.12.2 10.1.1.2 180 0x80000001 0x00D4E5 Based on this output, what can be concluded?

A network engineer runs the following command on Router R1: R1# show ip ospf interface GigabitEthernet0/0 GigabitEthernet0/0 is up, line protocol is up Internet Address 192.168.12.1/24, Area 0 Process ID 1, Router ID 10.1.1.1, Network Type BROADCAST, Cost: 10 Transmit Delay is 1 sec, State BDR, Priority 1 Designated Router (ID) 10.1.1.2, Interface address 192.168.12.2 Backup Designated router (ID) 10.1.1.1, Interface address 192.168.12.1 Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 oob-resync timeout 40 Hello due in 00:00:03 Neighbor Count is 1, Adjacent neighbor count is 1 Adjacent with neighbor 10.1.1.2 (Designated Router) Suppress hello for 0 neighbor(s) Based on this output, which statement is correct?

A network engineer runs the following command on Router R1: R1# show ip route ospf 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 a - application route + - replicated route, % - next hop override Gateway of last resort is not set O 10.2.2.0/24 [110/20] via 192.168.12.2, 00:12:34, GigabitEthernet0/0 O IA 10.3.3.0/24 [110/30] via 192.168.13.3, 00:10:21, GigabitEthernet0/1 Based on this output, what can be determined?

A network engineer runs the following command on Router R1: R1# show ip ospf neighbor 10.1.1.2 Neighbor 10.1.1.2, interface address 192.168.12.2 In the area 0 via interface GigabitEthernet0/0 Neighbor priority is 1, State is FULL, 6 state changes DR is 10.1.1.2, BDR is 10.1.1.1 Options is 0x12 (L L S R) Dead timer due in 00:00:36 Neighbor is up for 00:15:42 Index 1/1/1, retransmission queue length 0, number of retransmission 0 First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0) Last retransmission scan length is 0, time is 0 msec Last retransmission scan time is 0 msec Based on this output, what is the role of Router R1 on this segment?

A network engineer runs the following command on Router R1: R1# show ip ospf database router 10.1.1.2 OSPF Router with ID (10.1.1.1) (Process ID 1) Router Link States (Area 0) LS age: 150 Options: (No TOS-capability, DC) LS Type: Router Links Link State ID: 10.1.1.2 Advertising Router: 10.1.1.2 LS Seq Number: 80000002 Checksum: 0x1234 Length: 48 Number of Links: 2 Link connected to: a Transit Network (Link ID) Designated Router address: 192.168.12.2 (Link Data) Router Interface address: 192.168.12.2 Number of TOS metrics: 0 TOS 0 Metrics: 10 Link connected to: a Stub Network (Link ID) Network/subnet number: 10.2.2.0 (Link Data) Network Mask: 255.255.255.0 Number of TOS metrics: 0 TOS 0 Metrics: 10 Based on this output, which statement is correct?

A network engineer runs the following command on Router R1: R1# show ip ospf virtual-links Virtual Link OSPF_VL0 to router 10.1.1.3 is up Run as demand circuit DoNotAge LSA allowed. Transit area 1, via interface GigabitEthernet0/0, Cost of using 10 Transmit Delay is 1 sec, State POINT_TO_POINT, Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Hello due in 00:00:08 Adjacency State FULL Based on this output, what can be concluded?

A network engineer runs the following command on Router R1: R1# show ip ospf neighbor detail Neighbor 10.1.1.4, interface address 192.168.14.4 In the area 0 via interface GigabitEthernet0/2 Neighbor priority is 1, State is 2WAY, 2 state changes DR is 10.1.1.1, BDR is 10.1.1.4 Options is 0x12 (L L S R) Dead timer due in 00:00:38 Neighbor is up for 00:05:22 Index 1/1/1, retransmission queue length 0, number of retransmission 0 First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0) Last retransmission scan length is 0, time is 0 msec Last retransmission scan time is 0 msec Based on this output, what is the problem?

A network engineer runs the following command on Router R1: R1# show ipv6 ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.1.1.2 1 FULL/BDR 00:00:35 FE80::2 GigabitEthernet0/0 10.1.1.3 1 FULL/DR 00:00:32 FE80::3 GigabitEthernet0/1 Based on this output, which statement is correct regarding OSPFv3?

Examine the following OSPF configuration on router R1: router ospf 1 network 10.0.0.0 0.255.255.255 area 0 network 192.168.1.0 0.0.0.255 area 1 What is the effect of this configuration?

Consider this OSPFv3 configuration on router R2: ipv6 router ospf 10 router-id 2.2.2.2 area 0 authentication ipsec spi 256 md5 1234567890abcdef1234567890abcdef interface GigabitEthernet0/0 ipv6 address 2001:db8:1::1/64 ipv6 ospf 10 area 0 What is the effect of this configuration?

Examine this OSPF configuration snippet on router R3: router ospf 1 network 10.1.1.0 0.0.0.255 area 0 default-information originate always What is the effect of the default-information originate always command?

Consider this OSPF configuration on router R4: router ospf 1 network 192.168.1.0 0.0.0.255 area 0 neighbor 10.0.0.2 What is the effect of the neighbor statement?

Examine this OSPF configuration on router R5: router ospf 1 network 10.0.0.0 0.255.255.255 area 0 passive-interface default no passive-interface GigabitEthernet0/0 What is the effect of the passive-interface default command?

Consider this OSPF configuration on router R6: router ospf 1 network 10.0.0.0 0.255.255.255 area 0 area 0 stub What is the effect of the area 0 stub command?

What is the default OSPF hello interval on a point-to-point serial interface?

Which OSPF LSA type is used to advertise prefixes from other areas into the backbone area?

In OSPFv3, what is the purpose of the link-local address in the neighbor adjacency process?

Which TWO commands would a network engineer use to verify OSPFv2 neighbor state and adjacency issues on a Cisco IOS router? (Choose TWO.)

Which TWO statements about OSPFv3 (OSPF for IPv6) are true when comparing it to OSPFv2? (Choose TWO.)

Which THREE symptoms indicate a potential OSPFv2 neighbor adjacency problem due to a mismatch in configuration? (Choose THREE.)

Which TWO configuration steps are required to enable OSPFv3 on a Cisco IOS router for IPv6 routing? (Choose TWO.)

Which TWO commands can be used to verify OSPFv2 path selection and cost metrics on a Cisco IOS router? (Choose TWO.)

A large enterprise network is experiencing intermittent loss of connectivity to a subnet 10.10.10.0/24 from remote sites. Router R1 has the following relevant configuration: interface GigabitEthernet0/0 ip address 10.1.1.1 255.255.255.252 ip ospf 1 area 0 interface GigabitEthernet0/1 ip address 10.2.2.1 255.255.255.252 ip ospf 1 area 1 router ospf 1 area 1 range 10.10.0.0 255.255.248.0 Router R2 shows: show ip route 10.10.10.0 Routing entry for 10.10.8.0/21 Known via "ospf 1", distance 110, metric 20, type inter-area Last update from 10.1.1.2 on GigabitEthernet0/0, 00:05:32 ago What is the root cause?

A network engineer notices that routes redistributed from EIGRP into OSPF are causing routing loops. Router R1 has the following relevant configuration: router eigrp 100 redistribute ospf 1 metric 10000 100 255 1 1500 router ospf 1 redistribute eigrp 100 subnets metric-type 1 Router R2 shows: show ip route 192.168.1.0 Routing entry for 192.168.1.0/24 Known via "ospf 1", distance 110, metric 20, type E1 Last update from 10.1.1.1, 00:01:30 ago Also, R2 has a default route via R1. What is the root cause?

A router R1 is redistributing BGP routes into OSPF, but some prefixes are missing. Router R1 has the following relevant configuration: router bgp 65000 neighbor 10.1.1.2 remote-as 65001 address-family ipv4 unicast neighbor 10.1.1.2 activate network 172.16.0.0 mask 255.255.255.0 router ospf 1 redistribute bgp 65000 subnets metric 100 Router R2 shows: show ip ospf database external 172.16.0.0 OSPF Router with ID 10.1.1.1 Type-5 AS External Link States LS age: 600 Options: (No TOS-capability, DC) LS Type: AS External Link Link State ID: 172.16.0.0 Advertising Router: 10.1.1.1 LS Seq Number: 80000001 Checksum: 0x1234 Length: 36 Network Mask: /24 Metric Type: 2 (Larger than any valid route) TOS: 0 Metric: 16777215 Forward Address: 0.0.0.0 External Route Tag: 0 What is the root cause?

Two routers R1 and R2 are connected via Ethernet link, but OSPF adjacency is not forming. Router R1 has the following relevant configuration: interface GigabitEthernet0/0 ip address 10.1.1.1 255.255.255.252 ip ospf network point-to-multipoint ip ospf 1 area 0 Router R2 shows: show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.1.1.2 1 FULL/DR 00:00:35 10.1.1.2 GigabitEthernet0/0 But R2's configuration: interface GigabitEthernet0/0 ip address 10.1.1.2 255.255.255.252 ip ospf network broadcast ip ospf 1 area 0 What is the root cause?

An EIGRP network is experiencing stuck-in-active (SIA) routes after a link failure. Router R1 has the following relevant configuration: router eigrp 100 network 10.0.0.0 0.255.255.255 Router R2 shows: show ip eigrp topology 10.1.1.0/24 IP-EIGRP topology entry for 10.1.1.0/24 State: Active, 00:01:30, Reply status 10.2.2.2, 10.3.3.3 What is the root cause?

DMVPN spoke-to-spoke tunnel is not forming between two spokes. Hub router R1 has the following relevant configuration: interface Tunnel0 ip address 10.0.0.1 255.255.255.0 ip nhrp network-id 1 ip nhrp map multicast dynamic ip ospf 1 area 0 tunnel source GigabitEthernet0/0 tunnel mode gre multipoint Spoke R2 shows: show dmvpn Legend: Attrb -> S: Static, D: Dynamic, I: Incomplete Interface: Tunnel0, IPv4 NHRP Details Type:Spoke, NHRP Peers: 1 # Ent Peer NBMA Addr Peer Tunnel Add State UpDn Tm Attrb 1 192.168.1.1 10.0.0.1 UP 00:10:00 D Spoke R3 shows similar, but no spoke-to-spoke tunnel. What is the root cause?

MPLS LDP neighbors are not forming between two directly connected routers. Router R1 has the following relevant configuration: interface GigabitEthernet0/0 ip address 10.1.1.1 255.255.255.252 mpls ip Router R2 shows: show mpls ldp neighbor No LDP neighbors show mpls ldp discovery Local LDP Identifier: 10.1.1.1:0 Discovery Sources: Interfaces: GigabitEthernet0/0 (ldp): xmit/recv LDP: no Hello adjacencies What is the root cause?

Management traffic to a router's loopback interface is being dropped. Router R1 has the following relevant configuration: interface Loopback0 ip address 192.168.1.1 255.255.255.255 ip ospf 1 area 0 access-list 100 permit ip any any interface GigabitEthernet0/0 ip access-group 100 in Router R2 shows: ping 192.168.1.1 source 10.1.1.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 192.168.1.1, timeout is 2 seconds: ..... Success rate is 0 percent (0/5) What is the root cause?

VRF route leaking between two VRFs is causing unexpected reachability to a sensitive subnet. Router R1 has the following relevant configuration: vrf definition BLUE rd 100:1 ! address-family ipv4 route-target export 100:1 route-target import 100:2 vrf definition RED rd 100:2 ! address-family ipv4 route-target export 100:2 route-target import 100:1 interface GigabitEthernet0/0 vrf forwarding BLUE ip address 10.1.1.1 255.255.255.0 interface GigabitEthernet0/1 vrf forwarding RED ip address 10.2.2.1 255.255.255.0 router ospf 1 vrf BLUE network 10.1.1.0 0.0.0.255 area 0 router ospf 2 vrf RED network 10.2.2.0 0.0.0.255 area 0 A ping from a host in BLUE VRF to 10.2.2.2 (RED VRF) succeeds, but it should not. What is the root cause?

A network engineer runs the following command to troubleshoot an OSPF adjacency issue: R1# debug ip ospf adj *Mar 1 00:12:34.567: OSPF-1 ADJ RtrA: Interface GigabitEthernet0/0 going Up *Mar 1 00:12:34.568: OSPF-1 ADJ RtrA: 2 Way Communication to 10.1.1.2 on GigabitEthernet0/0, state 2WAY *Mar 1 00:12:34.570: OSPF-1 ADJ RtrA: NBR 10.1.1.2: Our router ID 1.1.1.1, his router ID 2.2.2.2 *Mar 1 00:12:34.571: OSPF-1 ADJ RtrA: NBR 10.1.1.2: Neighbor is not DR, state 2WAY *Mar 1 00:12:34.572: OSPF-1 ADJ RtrA: NBR 10.1.1.2: DR is 10.1.1.2, BDR is 10.1.1.1 *Mar 1 00:12:34.573: OSPF-1 ADJ RtrA: NBR 10.1.1.2: Build the Start DBD *Mar 1 00:12:34.574: OSPF-1 ADJ RtrA: NBR 10.1.1.2: Master/Slave negotiation done *Mar 1 00:12:34.576: OSPF-1 ADJ RtrA: NBR 10.1.1.2: Exchange done, loading started *Mar 1 00:12:34.578: OSPF-1 ADJ RtrA: NBR 10.1.1.2: Loading done *Mar 1 00:12:34.580: OSPF-1 ADJ RtrA: NBR 10.1.1.2: Full What does this output indicate?

A network engineer runs the following command to troubleshoot OSPF route propagation: R1# show ip ospf database router 2.2.2.2 OSPF Router with ID (1.1.1.1) (Process ID 1) Router Link States (Area 0) LS age: 45 Options: (No TOS-capability, DC) LS Type: Router Links Link State ID: 2.2.2.2 Advertising Router: 2.2.2.2 LS Seq Number: 80000005 Checksum: 0x1234 Length: 48 Number of Links: 2 Link connected to: a Transit Network (Link ID) Designated Router address: 10.1.1.2 (Link Data) Router Interface address: 10.1.1.2 Number of TOS metrics: 0 TOS 0 Metrics: 10 Link connected to: a Stub Network (Link ID) Network/subnet number: 192.168.1.0 (Link Data) Network Mask: 255.255.255.0 Number of TOS metrics: 0 TOS 0 Metrics: 10 What does this output indicate?

A network engineer runs the following command to verify OSPF interface details: R1# show ip ospf interface gigabitethernet0/0 detail GigabitEthernet0/0 is up, line protocol is up Internet Address 10.1.1.1/24, Area 0 Process ID 1, Router ID 1.1.1.1, Network Type BROADCAST, Cost: 10 Transmit Delay is 1 sec, State BDR, Priority 1 Designated Router (ID) 2.2.2.2, Interface address 10.1.1.2 Backup Designated router (ID) 1.1.1.1, Interface address 10.1.1.1 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 Can be protected by per-prefix Loop-Free Fast Reroute Can be used for per-prefix Loop-Free Fast Reroute repair paths Index 1/1, flood queue length 0 Next 0(0)/0(0) Last flood scan length is 1, maximum is 25 Last flood scan time is 0 msec, maximum is 4 msec Neighbor Count is 1, Adjacent neighbor count is 1 Adjacent with neighbor 2.2.2.2 (Designated Router) Suppress hello for 0 neighbor(s) What does this output indicate?

A network engineer runs the following command to troubleshoot OSPF route redistribution: R1# show ip ospf database external 5.5.5.5 OSPF Router with ID (1.1.1.1) (Process ID 1) Type-5 AS External Link States LS age: 120 Options: (No TOS-capability, DC, Upward) LS Type: AS External Link Link State ID: 5.5.5.5 (External Network Number) Advertising Router: 3.3.3.3 LS Seq Number: 80000001 Checksum: 0xABCD Length: 36 Network Mask: /32 Metric Type: 2 (Larger than any link state path) TOS: 0 Metric: 20 Forward Address: 0.0.0.0 External Route Tag: 0 What does this output indicate?

A network engineer runs the following command to troubleshoot OSPFv3 adjacency: R1# debug ipv6 ospf adj *Mar 1 00:15:23.456: OSPFv3-1-IPv6 ADJ Gi0/0: Rcv pkt from 2001:DB8:1::2, src 2001:DB8:1::2, area 0 *Mar 1 00:15:23.457: OSPFv3-1-IPv6 ADJ Gi0/0: Nbr 2.2.2.2: Our address 2001:DB8:1::1, his address 2001:DB8:1::2 *Mar 1 00:15:23.458: OSPFv3-1-IPv6 ADJ Gi0/0: Nbr 2.2.2.2: Neighbor is not DR, state 2WAY *Mar 1 00:15:23.459: OSPFv3-1-IPv6 ADJ Gi0/0: Nbr 2.2.2.2: DR is 2001:DB8:1::2, BDR is 2001:DB8:1::1 *Mar 1 00:15:23.460: OSPFv3-1-IPv6 ADJ Gi0/0: Nbr 2.2.2.2: Build the Start DBD *Mar 1 00:15:23.462: OSPFv3-1-IPv6 ADJ Gi0/0: Nbr 2.2.2.2: Master/Slave negotiation done *Mar 1 00:15:23.464: OSPFv3-1-IPv6 ADJ Gi0/0: Nbr 2.2.2.2: Exchange done, loading started *Mar 1 00:15:23.466: OSPFv3-1-IPv6 ADJ Gi0/0: Nbr 2.2.2.2: Loading done *Mar 1 00:15:23.468: OSPFv3-1-IPv6 ADJ Gi0/0: Nbr 2.2.2.2: Full What does this output indicate?

A network engineer runs the following command to verify OSPFv3 database: R1# show ipv6 ospf database router 2.2.2.2 OSPFv3 Router with ID (1.1.1.1) (Process ID 1) Router Link States (Area 0) LS age: 60 LS Type: Router Links Link State ID: 0.0.0.0 Advertising Router: 2.2.2.2 LS Seq Number: 80000003 Checksum: 0x5678 Length: 40 Number of Links: 1 Link connected to: a Transit Network (Link ID) Interface ID: 2 (Link Data) Neighbor Interface ID: 1 Number of TOS metrics: 0 TOS 0 Metrics: 10 What does this output indicate?

A network engineer runs the following command to troubleshoot OSPF neighbor states: R1# show ip ospf neighbor detail Neighbor 2.2.2.2, interface address 10.1.1.2 In the area 0 via interface GigabitEthernet0/0 Neighbor priority is 1, State is FULL, 6 state changes DR is 10.1.1.2, BDR is 10.1.1.1 Options is 0x42 (LLS, DC) LLS Options is 0x1 (LR) Dead timer due in 00:00:36 Neighbor is up for 00:12:34 Index 1/1/1 Retransmission queue length 0, number of retransmission 1 First 0x0(0)/0x0(0)/0x0(0) Next 0x0(0)/0x0(0)/0x0(0) Last retransmission scan length is 1, maximum is 1 Last retransmission scan time is 0 msec, maximum is 0 msec What does this output indicate?

A network engineer runs the following command to verify OSPF SPF calculations: R1# show ip ospf statistics OSPF Router with ID (1.1.1.1) (Process ID 1) Area 0: SPF algorithm executed 12 times SPF calculation time (in msec): Total: 12, Average: 1.0 Minimum: 0, Maximum: 2 Last SPF due to: LSA change Number of LSA changes: 5 Number of LSA deletions: 2 Number of LSA additions: 3 Number of LSA updates: 0 Area 1: SPF algorithm executed 3 times SPF calculation time (in msec): Total: 3, Average: 1.0 Minimum: 0, Maximum: 1 Last SPF due to: LSA change Number of LSA changes: 2 Number of LSA deletions: 0 Number of LSA additions: 2 Number of LSA updates: 0 What does this output indicate?

A network engineer runs the following command to troubleshoot OSPF route installation: R1# show ip route ospf 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 a - application route + - replicated route, % - next hop override Gateway of last resort is not set O 10.1.1.0/24 [110/10] via 10.1.1.2, 00:12:34, GigabitEthernet0/0 O IA 192.168.1.0/24 [110/20] via 10.1.1.2, 00:10:00, GigabitEthernet0/0 O E2 5.5.5.5/32 [110/20] via 10.1.1.2, 00:05:00, GigabitEthernet0/0 What does this output indicate?

What is the default OSPF hello interval on a Cisco IOS-XE router for a broadcast network type?

Which OSPF packet type is used to send link-state advertisements (LSAs) and is acknowledged by the receiver?

In OSPF, what is the default administrative distance for intra-area routes on a Cisco IOS-XE router?

Which LSA type is used by OSPF to advertise prefixes from other routing protocols (redistribution) and has a default metric of 20?

Which OSPF network type defaults to a hello interval of 30 seconds and a dead interval of 120 seconds on Cisco IOS?

In OSPFv3, which authentication method is supported by default?

What is the default OSPF reference bandwidth used in the metric calculation on Cisco IOS-XE?

Which OSPF LSA type is flooded only within the originating area and is used for loop prevention by describing the topology of the area?

In OSPF, what is the default behavior for auto-summary on Cisco IOS-XE?

Drag and drop the steps to troubleshoot OSPF DR/BDR election on a multi-access segment into the correct order, from first to last.

Drag and drop the steps to troubleshoot OSPF adjacency or connectivity failures into the correct order, from first to last.

Drag and drop the steps to verify and validate OSPF operational state into the correct order, from first to last.

Which TWO statements correctly describe the behavior of OSPFv3 when troubleshooting neighbor adjacency issues on a Cisco IOS-XE router? (Choose TWO.)

An engineer is troubleshooting an OSPFv2 adjacency that remains stuck in EXSTART state. Which TWO actions should the engineer take to resolve the issue? (Choose TWO.)

Which TWO statements about OSPFv2 LSA types and their troubleshooting significance are true? (Choose TWO.)

Which TWO commands can be used to verify OSPFv3 interface parameters and troubleshoot adjacency issues? (Choose TWO.)

Which TWO statements about OSPFv2 authentication troubleshooting are true? (Choose TWO.)

An engineer configures OSPFv2 on two routers with a direct Ethernet link. The routers are stuck in the EXSTART state. Which is the most likely explanation?

An engineer configures OSPFv3 on two routers. Both routers are in the same area, but they fail to form an adjacency. Which is the most likely explanation?

An engineer configures a distribute-list on an OSPF router to filter routes. However, the routes are still being advertised to neighbors. Which is the most likely explanation?

An engineer configures OSPF area range on an ABR to summarize routes. After configuration, some routes are still being advertised as individual LSAs into the backbone. Which is the most likely explanation?

An engineer configures OSPF with authentication on a point-to-point link. The adjacency forms, but routes are not being exchanged. Which is the most likely explanation?

An engineer configures OSPFv3 with multiple areas. On the ABR, routes from area 1 are not being advertised into area 0. Which is the most likely explanation?

An engineer configures OSPFv2 with a virtual link to connect a non-backbone area to area 0. The virtual link is up, but routes from the non-backbone area are not being advertised into area 0. Which is the most likely explanation?

An engineer configures OSPFv3 with a filter-list on an ABR to filter prefixes. After configuration, the routes are still being advertised. Which is the most likely explanation?

An engineer configures OSPFv2 with a route-map to set the metric on redistributed routes. After redistribution, the metric is not being set as expected. Which is the most likely explanation?