Network Addressing and Basic Troubleshooting Module 4 – 6 Checkpoint Test Online

Hint

The calculation should start with the IPv4 prefix 10.25.0.0/16, a subnet mask of 255.255.255.128 is required to create 512 subnets, each can accommodate at least 100 hosts. The subnet mask 255.255.255.128 is equivalent to the notation of /25. The difference between /16 and /25 is 9 bits. 9 bits will produce 512 subnets. A subnet mask notation /25 allows 7 bits for hosts. 7 bits provides for 126 hosts.

Hint

WAN links needing only 2 useable addresses use a /30 subnet, so 4 additional bits would need to be borrowed.

Hint

5 bits must be left to accommodate 25 network devices. With 5 host bits, up to 30 network devices can be placed on a network with a /27 prefix. 5 bits for hosts will yield 25=32 host addresses, but only 30 addresses are valid to be assigned to devices.

Hint

Prefix lengths of /28 and /29 are the most efficient to create subnets of 16 addresses (to support 10 hosts) and 8 addresses (to support 6 hosts), respectively. Addresses in one subnet must also not overlap into the range of another subnet.

Hint

In order to accommodate 40 devices, 6 host bits are needed. With 6 bits, 64 addresses are possible, but one address is for the subnet number and one address is for a broadcast. This leaves 62 addresses that can be assigned to network devices. The mask associated with leaving 6 host bits for addressing is 255.255.255.192.

Hint

Creating 64 subnets requires six bits. If the subnet mask is moved six bits to the right, the new subnet mask becomes 255.255.255.128.

Hint

Options matched to the correct selection.

Link-Local	Multicast	Global Unicast
FE80:0:56BA:FFEE:A0B4:47FF:FE36:532B	FF02::2	2001:DB8:10::12
FE80::1	FF02::1:FF3A:25C9	2001:DB8:A1:0B:C78::1

Hint

Place the options in the following order:

This network portion of the address is assigned by the provider.	global routing
This part of the address is used by an organization to identify subnets.	subnet ID
This part of the address is the equivalent to the host portion of an IPv4 address.	interface ID

Hint

An IPv6 address comprises 128 bits represented as eight blocks of four hexadecimal digits. The last four blocks of the address represent the interface ID and is controlled by the administrator.

Hint

With SLAAC, the default gateway for IPv6 clients will be the link-local address of the router interface that is attached to the client LAN. The IPv6 addressing is dynamically assigned via the ICMPv6 protocol. SLAAC is a stateless method of acquiring an IPv6 address, a method that requires no servers. When a client is configured to obtain its addressing information automatically via SLAAC, the client sends a router solicitation message to the IPv6 all-routers multicast address FF02::2. The router advertisement messages are sent by routers to provide addressing information to clients.

Hint

When IPv6 is enabled on any interface, that interface will automatically generate an IPv6 link-local address.

Hint

SLAAC uses ICMPv6 messages when dynamically assigning an IPv6 address to a host. DHCPv6 is an alternate method of assigning an IPv6 addresses to a host. ARPv6 does not exist. Neighbor Discovery Protocol (NDP) provides the functionality of ARP for IPv6 networks. UDP is the transport layer protocol used by DHCPv6.

Hint

FF02::1 is the all-nodes multicast group within the scope of the local link. A packet with this destination address is received and processed by all IPv6-enabled interfaces.

Hint

FF02::2 identifies all IPv6 routers that exist on the link or network. FF02::1 is the target for all IPv6 enabled devices on the link or network.​

Hint

ICMPv6 includes four new message types: Router Advertisement, Neighbor Advertisement, Router Solicitation, and Neighbor Solicitation.

Hint

Options matched to the correct selection.

providing address resolution	supporting dynamic address allocation and SLAAC	informing a better next-hop selection
neighbor solicitation	neighbor advertisement	router solicitation

Hint

When an IPv6 host needs to initiate a communications with other hosts on the same network, it sends a neighbor solicitation message to start the address resolution process.

Hint

When an IPv6 need to start an MAC address resolution process, the host sends a neighbor solicitation message via multicast.

Hint

IPv6 Neighbor Discovery protocol, also referred to as ND or NDP, provides address resolution, router discovery, and redirection services for IPv6 using ICMPv6.

Hint

When an IPv6 host sends a neighbor solicitation message to another IPv6 host on the same Ethernet network, the sending host creates an Ethernet frame and add a multicast MAC address in the Destination MAC address field. This multicast MAC address maps the special solicited-node multicast address derived from the destination IPv6 address.

Hint

When performing SLAAC, IPv6 clients receive network configuration information from router advertisement messages that are sent by a local router.

Hint

If the same mask is to be used, then the network with the most hosts must be examined for number of hosts. Because this is 10 hosts, 4 host bits are needed. The /28 or 255.255.255.240 subnet mask would be appropriate to use for these networks.​

Hint

An easy way to identify that an address was probably created by using EUI-64 is the fffe located in the middle of the interface ID.

Hint

When an IPv6 host receives an ICMPv6 neighbor solicitation message for MAC address resolution, the host returns a neighbor advertisement message to provide the MAC address.