some practice question disagreements

prolificprolific Posts: 22Member ■□□□□□□□□□
hello, ive been doing some sample practice questions on various sites that give them for free and i thought some of their answers were wrong, but i need confirmation from some of you :)

1. describe link-state routing protocols.

a. common view of entire topology
b. exchange routing tables with neighbors
c. calculate shortest path
d. event triggered updates
e. periodic updates..

they said the correct answers are b, c, d. I thought the correct ones were a, c, d...My reasoning for this is that link-state protocols have a very good understanding of the entire networking topology. Also i think that they send routing updates not only to their neighbors but to all routers that they can reach

2. would mac addresses be associated with serial interfaces? eg. would a show arp on a router display listings for a mac address to serial interface mapping ?

i believe mac addresses are only associated with ethernet interfaces. am i correct?

3. admin wants to config switch over telnet session from outside the lan. which would be required for this to be possible

a. switch has to have ip/subnet mask/default gateway configured
b. switch has to be connected to router over vlan trunk
c. switch must be reachable through a port connected to its management vlan
d. switch console port must be connected to ethernet LAN
e. switch management vlan must be created and have a membership of at least one switch port.
f. switch must be configured as SMTP server.

they said the answers were A, E... However, i think the answers are A, C.. E to me doesnt make sense because you dont need to create the management vlan because its already created by default[vlan1].. Any opinions on this one?

4. what are benefits of vlans

a. increases # of broadcast domains
b. decreate # of broadcast domains
c. increase # of collision domains
d. decrease # of collision domains

it says only pick one answer. I know that vlans do both a and c .. but if they say just pick 1 answer, which one is more Correct to pick ?

5. how can u connect a pc directly to a router
a. conect pc's etheret port ro routers ethernet port using crossover cable
b. conenct pc's com port 2 routers console port using crossover cable

it says answer is a .. why cant u use a converter that plugs into the computers serial port on one side and attaches to the routers console port on the other side.. isnt that correct as well ?

also ive heard of some people refer to crossover cables as rollover cables.. are these terms interchangable or are there differences between the two.

Thanks :)
There are 10 kinds of people in the world, those that understand binary and those that don't.


  • sikdoggsikdogg Posts: 43Member ■■□□□□□□□□
    On question 1)
    I would agree with B, C, and D. Link-state routers create neighbors relationships with routers that they can reach. Although link-state protocols have topology tables that give them a good understanding of the network topology, they only exchange their tables with neighbors. B is more correct than A.

    Question 2)
    MAC addresses are associated with ALL interfaces.

    Question 3)
    I agree with A and E. Switch ports are not connected to a VLAN. Switch ports can be assigned membership to a VLAN.

    Question 4)
    Correct answer is A. Switches, be default, increase collision domains (each port), but is one large broadcast domain. VLANs allow you to break up the switch into separate broadcast domains.

    Question 5)
    Correct answer is A. A router's relation to a hub/switch is similar to that of a PC, it is an end device. Therefore, connecting a PC directly to a router is just like connecting a PC to a PC. A crossover cable is required.

    A crossover cable is NOT a rollover cable. A crossover cable is one where the transmit and receive pairs are switched (one side is wired 123XX6XX the other end is 361XX2XX). A rollover cable is one where all wire pairs are reverse (One side is wired 12345678, the other end is 87654321).
  • BlindmanBlindman Posts: 3Member ■□□□□□□□□□
    Are you 100% sure that Serial ports have a MAC address. If you
    SHOW INT S0 on a router no MAC address is given
    SHOW INT E0 will display a MAC address.

    I was of the understanding that MAC address belong to Ethernet technology. And that serial connections use different layer 2 addressing
  • RussSRussS Posts: 2,068Member
    As far as I am aware a MAC address is traditionally only found on a NIC or on a network port. However if one looks at something like a print server (maybe an Intel Netport Express which has 2 parallel ports and 1 serial port) you will find that the MAC address can be found by accesssing the serial or parallel ports as well as the ethernet (or token ring) ports. All the same MAC address, but could be construed as those ports having a MAC address.
    FIM website of the year 2007
  • headcaseheadcase Posts: 30Member ■■□□□□□□□□
    RusS I sent you a pm :)
  • WebmasterWebmaster Posts: 10,292Admin Admin
    Profolic, 'free' questions doesn't typically mean they can be copied or reproduced without permission... Please try to rephrase any questions you have in a concept, or question without the exact same multiple choice answer as the 'original' question.

    As for the routing protocols, remember that link-state protocols use multicast to send routing updates to neighbors (neighbors can be virtual, not only directly physical connected), and distance vector routing protocols broadcast their entire routing table out of every interface by default... the results is that distance vector protocols do not send updates directly to their neighbors, but the neighbors are typically the only ones that receives the updates, because a router does not forward broadcasts by default... but in a way they also send updates to their neigbors...
    I would have choosen answer a also as correct, but that is how it should be but not always the case. So like Sikkdog said, b is more correct than a.
  • sikdoggsikdogg Posts: 43Member ■■□□□□□□□□
    My appologies, Blindman is correct. I don't know what I was thinking. Serial interfaces do not have MAC addresses.

    That's what happens when i try to chew gum and walk at the same time.
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