Chapter_8 part_2

Question 1

authentication for ospf: null?

Answer 1

no authentication used

Question 2

authentication for ospf?: simple

Answer 2

plaint text authentication… older technology. password is sent in the update (ospf) in plain txt.

Question 3

authentication for ospf: MD5 authentication

Answer 3

password is never exchanged between peers, most secure method. password is calculated used md5 algorithms.

Question 4

DBD?

Answer 4

Database Descriptor packet

Question 5

what 2 states should ospf be in for log period of time?

Answer 5

2-way and full state

Question 6

what is 2-way state in ospf?

Answer 6

means the router has sent and received hello packets with its neighbor. stays in this state with all routers except the DR or BDR where it is in a state of Full (when on a broadcast network).

Question 7

what is Full state in ospf?

Answer 7

routers are fully adjacent (routers have converged) with each other. All the router and network LSAs are exchanged and the routers’ databases are fully synchronized. **the router should always be in full state unless the network is a broadcast network and then it is in 2-way state with all neighbor routers except the DR or BDR.

Question 8

default administrative distance 110 is what?

Answer 8

ospf

Question 9

what command do u use to reset the ospf neighbor adjacency without resetting/restarting the router?

Answer 9

clear ip ospf ‘process-id’ process

Question 10

with the following command what is shown?show ip route ospf

Answer 10

displays only the ospf learned routes in the routing table.

Question 11

what does this command display? show ip ospf

Answer 11

process id, router id, ospf earea info. and last time spf algorithm was processed.

Question 12

what command do u use to see the ospf paramaters configured on an interface, ospf process id, areas that the interfaces are in, cost of int., hello and dead intervals?

Answer 12

show ip ospf interface

Question 13

what command is used to: see neighbor router id, neighbor priority, ospf state, dead timer, neighbor int. address.

Answer 13

show ip ospf neighbor

Question 14

the command shows what? show ip protocols

Answer 14

ospf process id, router id, networks the router is advertising, default admin. distance, etc…

Question 15

if the following command is set on an interface what occurs? passive-interface

Answer 15

ospf routing updates are not able to pass between or out that interface. this keeps adjacency tables from forming and can cause ospf neighbor issues. **disable using the np passive-interface command

Question 16

what is MTU?

Answer 16

The MTU size is the largest network layer packet that the router will forward out each interface. if the MTU does not match between interfaces on the same line then an adjacency in ospf will fail.

Question 17

show ipv6 protocols

does what?

Answer 17

OSPFv3 process ID, the router ID, and the interfaces the router is receiving updates from

Question 18

The default priority of multiaccess broadcast interfaces is?

Answer 18

1… therefore another value must break a tie is all the interface priorities are equal. this tie breaker could be: router with highest router id, etc.