Routing Questions And Answers

1 The job of a router is to _____.

  • assign IP addresses to hosts on the network

    A DHCP server assigns IP addresses to hosts.

  • connect networks with different network IDs .While some routers have many other built-in services, the primary job of a router is to connect networks with different network IDs.

  • allow outside hosts to initiate contact with hosts on the LAN side of a network

  • map IP addresses against MAC addresses

Introducing routers

2 What is the role of port numbers in IP headers?

  • Port numbers identify which interfaces on a router should receive data in and which interfaces should forward data out

  • Port numbers identify the sending and receiving processes between two hosts

    Correct

    Port numbers identify sending and receiving processes in a sender and receiver.

  • Port numbers identify which connectors on a switch that should receive data in and which should forward data out

  • Port numbers identify the path of routers between any two hosts that need to communicate with each other

3.Which statement is true of a NAT router?

  • NAT routers allow public addresses to exist on the LAN side of the router.

  • All hosts on the LAN side of a NAT router are assigned the same IP address as the public address in the router.

  • The NAT function is performed at the ISP facility.

  • NAT routers replace the source IP address with its own IP address.

    Correct

    NAT routers replace the source IP address with its own IP address and then restore the original IP header when a response comes back so that the results can be sent to the originator.

4. Most SOHO routers come with NAT enabled.

  • TRUE

    Correct

    Most SOHO routers come with NAT enabled. It can be disabled and/or enabled in one of the router's administration settings.

5.Port forwarding allows which of the following?

  • Registers a LAN side host with a portable DNS address

  • One host on the LAN side of a NAT router to be assigned with the same public address of the router's WAN interface

  • Public addresses to be assigned to the LAN side of a NAT router

  • Outside access to hosts on the LAN side of a NAT router

    Correct

    Port forwarding enables access to hosts on the LAN side of a NAT router from beyond the WAN interface of the router.

6. A tech has just installed a new SOHO router for a client. Which security task should the tech perform first?

  • Disable the DHCP server.

  • Disable port forwarding.

  • Change the administrator name and password.

    Correct

    The default admin name and password of all makes and models are well known. It is critical to change these right away to prevent the router from being hacked.

  • Enable MAC address cloning.

7. Which feature of a SOHO router is not typically found in an enterprise router?

  • Graphical or textual management interface

  • Two or more router interfaces

  • Each interface in the router must be configured

  • Built-in switch

    Correct

    Very few enterprise routers have a built-in switch.

8. Which statement is not true of static routes?

  • Static routes are entered manually and must be manually changed by a human.

  • Hosts can have static routes.

  • Static routes are entered manually but can be automatically changed by the router.

    Correct

    Static routes must be manually entered by a human and, once entered, cannot be automatically changed by a router. When a router automatically changes a route, this is called dynamic routing and is the opposite of static routing.

  • Routers can have static routes.

9. Which of the following is a not an element of a route metric?

  • Bandwidth

  • MTU

  • Hop distance

    Correct

    The physical distance between to routers is not considered when defining a metric.

  • Cost

10. Which of the following is not a characteristic of the RIP routing protocol?

  • RIP is an interior gateway protocol.

  • RIP supports a maximum hop count of 127 hops.

    Correct

    Router Information Protocol (RIP) supports a maximum hop count of 15 hops, not 127 hops.

  • The primary metric in RIP is hop count.

  • RIP is a distance vector protocol.

11. Which of the following is not a characteristic of the OSPF routing protocol?

  • OSPF routers in an area elect a designated router and a backup designated router.

  • OSPF is a distance vector protocol.
    Open Shortest Path First (OSPF) is not a distance vector protocol, it is a link state protocol.

  • OSPF is a link state protocol.

  • OSPF routers are grouped into areas.

OSPF

12. Which of the following is not a characteristic of the BGP routing protocol?

  • OSPF is the primary routing protocol between Ases. Border Gateway Protocol (BGP) uses OSPF (and other routing protocols) within autonomous systems but not between different ASes.

  • BGP is a hybrid of distance vector and link state routing protocols.

  • The primary job of BGP is to route between Ases.

  • BGP is broken up into divisions called Autonomous Systems (AS).

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