The MTU does not match on both interfaces

OSPF is not enabled on one of the routers

The Router ID is the same on both routers

A OSPF Hello has not been received from the neighbor

89

87

85

83

Area Border Router

Autonomous System Boundary Router

Designated Router

All routers within an OSPF area.

The age for newly created link state information is set to 0 for OSPF and 1200 for IS-IS

The age for newly created link state information is set to 1200 for OSPF and 0 for IS-IS

The age is incremented or decremented as it is flooded from router to router and as it is held in the topological database.

The age is incremented or decremented only as it is held in the topological database and not as it is flooded router to router.

The system ID

The loopback address

The sequence number of the hello packet

The device that first initiated communication becomes the DIS

config>filter# default-action XXX

config>filter>ip-filter# default-action XXX

config>filter# default-mode XXX

config>filter>ip-filter# default-mode XXX

The router with the lowest priority is the DR.

The router with the highest priority is the DR.

If priorities are the same, the DR is chosen based on the lowest RID.

If priorities are the same, the DR is chosen based on the highest RID.

1

2

3

4

6

7

Routers R1 and R2 are L2 routers. Routers R3 and R4 are L1/L2 routers

Routers R1, R2, and R4 are L1/L2 routers. Router R3 is an L1 router,

Routers R1, R2, and R3 are L2 routers. Router R4 is an L1 router,

Routers R1 and R2 are L1/L2 routers. Routers R3 and R4 are L1 routers

1

2

3

4

6

7

L1 routers

L2 routers

L1/L2 routers

L1 and L2 routers

Area addresses TLV

Intermediate system neighbors

TLV Authentication information TLV

Intermediate system neighbors

TLV Area addresses

TLV LSP entries TLV

The IP internal reachability information

TLV Area Addresses

TLV Authentication Information TLV

The IP external reachability information

TLV Area addresses

TLV Intermediate system neighbors TLV

Black hole

Default gateway

Gateway path

Proxy ARP

The router sends a copy of the LSP from its database to its neighbor

The router updates its database with the LSP and floods a copy to its other neighbors.

The router updates its database with the LSP, acknowledges the LSP with a PSNP and floods a copy to its other neighbors.

The router updates its database with the LSP and acknowledges it with a PSNP.

To support classful routing protocols.

To allow IP routes to be defined using any number of bits for the network portion of the address.

To allow interdomain routing between an IGP and EGP such as OSPF and BGP.

To simplify the allocation of IP address space by defining a fixed size for the network portion of the address for each of the address classes.

With a Router LSA originated by R1

With a Router LSA originated by R5

With a Router LSA originated by R4

With an Inter-Area Prefix LSA originated by R1

With an Inter-Area Prefix LSA originated by R5

With an Inter-Area Prefix LSA originated by R4

Add the "originate-default-route" option in the NSSA area configuration on router R3

Add the "summaries" option to the NSSA area configuration on router R1

Make a static route on router R1 to 192.168.3.1

Make a default route on router R2

Intra-Area Prefix LSA

Inter-Area Prefix LSA

Inter-Area Router LSA

AS External LSA

Link

Intra-Area Prefix

Inter-Area Prefix

Inter-Area Router

A Type 4 LSA is not generated in a single area AS.

A Type 4 LSA is generated by the ABRs of the area that contains the ASBR.

A Type 4 LSA advertises the external networks connected to the ASBR.

A Type 4 LSA is not flooded in the area that contains the ASBR.

CPM

MDA

Switch Fabric

IOM

Next Header

Traffic Class

Hop Limit

Fragment Offset

Flow Label

1

10

100

1000

Router LSA

AS External LSA

Intra-Area Prefix LSA

Inter-Area Prefix LSA

Network LSA

2001:0da8:::0024:0000:4ab9:03

2001:0da8::0024::4ab9:0300

2001:da8::24::4ab9:300

2001:da8::24:0:4ab9:300

Down

Initializing

2-way

Full

1

2

3

4

6

7

There are three types of LSPs: L1, L2 and L1/L2.

An LSP packet contains the ATT bits and the IS-type bits.

The lower the LSP sequence number, the more current the update.

Separate databases are maintained for L1 „ L2, and L1/L2 LSPs.

The OSPF internal preference

The IS-IS Level 1 internal preference

The IS-IS Level 2 internal preference

The OSPF external preference

The IS-IS Level 2 external preference

The IS-IS Level 1 external preference

Routers broadcast the entire route table to all neighbors.

Information about directly connected links is sent to all neighbors.

An adjacency database is maintained by each router.

The sequence number for an update is incremented as it is flooded from router to router.

The topological database is the same for all routers in a single area.

Broadcast

Non-broadcast multi-access

Point-to-point

Point-to-multipoint

show router ospf area

show router ospf neighbor

show router ospf interface

show router ospf status

Router R3's routing table can only contain one of the routes, which will result in route flapping.

Router R3's routing table will have one entry for 10.1.1.0/24 and one entry for 10.1.2.0/24.

The networks will be represented with one entry of 10.0.0.0/8 in router R3's routing table.

The networks will be represented with one entry of 10.0.0.0/24 in router R3's route table.

They are sent using multicast MAC addresses 0180:0200:0014.

They are sent using multicast MAC addresses 0180:c200:0015.

They are sent using a unicast address.

None of the above.

As soon as the LSP is transmitted.

When an acknowledgment is received in the form of PSNP.

When an older LSP is received.

When a newer or same aged LSP is received.

Only when a newer LSP is received

The router R6 interface is in a multi-access segment. It is neither the DR nor the BDR for the segment. The DR for this segment would be the router with router ID 10.10.10.5.

The router R6 interface is in a multi-access segment. It is neither the DR nor the BDR for the segment; however, this command does not indicate whether 10.10.10.3 or 10.10.10.5 is the DR or BDR.

The router R6 interface is in a multi-access segment. It is the BDR, which is why it is not adjacent to the other routers.

The router R6 interface is in a multi-access segment. It is neither the DR nor the BDR for the segment. The DR for this segment would be the router with router ID 10.10.10.3.

Fast reroute capability

Control traffic prioritization

Route redistribution

Traffic engineering extensions

Cut through forwarding

Each router constructs its own link-state database with updates received from neighbors.

When a router performs an SPF computation, it sends the results to its neighbors.

An SPF computation is done by each router to determine the best path to destination prefixes

The link-state database is identical for all routers in a single area routing domain.

IS-IS supports VLSM and CIDR.

IS-IS uses OSI addressing.

IS-IS supports manual summarization

IS-IS uses periodic Hello messages.

Router R1 to router R7 will follow (R1-R2-R4-R6-R7). Router R7 to R1 will follow (R7-R6-R4-R2-R1)

Router R1 to router R7 will follow (R1-R2-R4-R6-R7). Router R7 to R1 will follow (R7-R6-R5-R3-R1)

Router R1 to router R7 will follow (R1-R3-R5-R6-R7). Router R7 to R1 will follow (R7-R6-R4-R2-R1)

Router R1 to router R7 will follow (R1-R3-R5-R6-R7). Router R7 to R1 will follow (R7-R6-R5-R3-R1)

Router R1 summarizes the prefixes from router R3 as 192.168.0.0/16 and router R2 does not summarize the prefixes.

Router R1 does not summarize the prefixes from routers R3 and R2 summarizes them as 192.168.0.0/16.

Router R1 summarizes the prefixes from router R3 as 192.168.0.0/20 and router R2 does not summarize the prefixes.

Router R1 does not summarize the prefixes from routers R3 and R2 summarizes them as 192.168.0.0/20.

Both routers R1 and R2 summarize the prefixes from R3 as 192.168.0.0/20.

Neither router R1 nor router R2 summarizes the prefixes from router R3.

10.10.10.2

10.10.10.3

10.10.10.4

10.10.10.6

There is no ASBR configured in the network.

The area ID does not have to match.

The value of the E bit in the options field does not have to match.

The value of the Hello interval does not have to match.

The value of the network mask does not have to match.

The area ID, the E bit value, the Hello interval and network mask must all match.

Operationally down interfaces in OSPF

Fully adjacent virtual links

Waiting state broadcast links

Fully adjacent point-to-point links

Loopback Interfaces in OSPF