Module 6: Network design and the access layer Flashcards
(80 cards)
this includes:
- preamble
- Start Frame Delimiter (SFD)
- destination MAC address
- source MAC address
- type / length
- data
- Frame Check Sequence (FCS)

what 7 components make up the
ethernet frame format
The ethernet standard defines a minimum and maximum frame size of which the preamble and start frame delimiter (SFD) are not included
If the ethernet frame does not lie within the minimum and maximum boundaries then the frame will be discarded
how is the
ethernet frame size determined
and what actions take place if these ae not followed
this is an area of a network that a single ethernet broadcast frame will be flooded to.
Routers do not forward ethernet broadcasts and so this will usually be the boundary of this
what is a
broadcast domain
and what defines the boundarys
in 3 steps describe the steps involved when a host uses the
Address Resolution Protocol (ARP)
- The sending host creates and sends a frame addressed to a broadcast MAC address. Contained in the frame is a message with the IPv4 address of the intended destination host.
- Each host on the network receives the broadcast frame and compares the IPv4 address inside the message with its configured IPv4 address. The host with the matching IPv4 address sends its MAC address back to the original sending host.
- The sending host receives the message and stores the MAC address and IPv4 address information in a table called an ARP table.
this has a:
minimum size of: 64 Bytes
maximum size of: 1518 Bytes
what is the
minimum and maximum size of an ethernet frame
this is a table that contains MAC addresses corresponsing to an IP address
devices such as P.Cs and routers will have one of these stored

what is an
ARP table
it does this by inspecting the source MAC address of the ethernet frame. if it does not exists in its MAC address table then it will add it to the associated port the frame entered the switch
how does a switch learn about new MAC addresses
this layer will:
contain network devices such as:
- switches
- routers
This is the backbone of the network and will provide high speed and redundant connections between the distribution layer devices it is also the last layer of the hierarchical design and any traffic that is bound for the internet will pass through here
describe the
core layer
of the hierarchical layer network design
the values for this are a:
minimum of: 46 Bytes
maximum of: 1500 Bytes
what is the
minumum and maximum size of the data that can be encapsulated within an ethernet frame
this part of the frame tells the receiving Network Interface Card (NIC) that it is about to start receiving the data concerned with the ethernet frame
what is the
Start Frame Delimiter (SFD)
of the ethernet frame
this is an ethernet broadcast message that is sent out by a host when it knows the destination IP address but does not know the destination MAC address of a host
what is an
ARP request
describe the
access layer
of the hierarchical layer network design
this layer will:
contain host devices such as:
- P.Cs
- servers
- access points
- switches
the devices will be separated into networks if any traffic must leave the network then it will travel up to the next layer of the design; the distribution layer
this is an ethernet frame that has a destination address of
FF-FF-FF-FF-FF-FF
That is 48 bits all set to 1
what is an
ethernet broadast message
what is the
Source mac address
of the ethernet frame
this is the MAC address of the sender of the ethernet frame
what is the
minumum and maximum size of the data that can be encapsulated within an ethernet frame
the values for this are a:
minimum of: 46 Bytes
maximum of: 1500 Bytes
what is the
Frame check sequence
of the ethernet frame
this is here for error checking and ensuring that the frame was delivered correctly
if an IP packet must travel to a new network what happens to the ethernet frame
when this situation occurs the IP packet will reach a router at which point it will discard the ethernet frame and create a new ethernet frame with
- the source address as its own mac address
- the destination address as the host MAC address that matches the IP address (if applicable and using its ARP table)
a switch builds this so that hosts can communicate on a dedicated channel, where all of the bandwidth on that channel is reserved for the two hosts
describe the
circuit
that a switch builds
what is an
ARP reply
this is a message sent in response to a ARP request when the host has a matching IP address of the one within the ARP request
how is the
ethernet frame size determined
and what actions take place if these ae not followed
The ethernet standard defines a minimum and maximum frame size of which the preamble and start frame delimiter (SFD) are not included
If the ethernet frame does not lie within the minimum and maximum boundaries then the frame will be discarded
what is the
Destination mac address
of the ethernet frame
this is the MAC address of the Network Interface Card (NIC) receiving the frame
this is the MAC address of the Network Interface Card (NIC) receiving the frame
what is the
Destination mac address
of the ethernet frame
this part of the ethernet frame will give detail of either the type of data inside the data field (I.e IPv4 or IPv6) or it will tell you the length of the data within the data field
what is the
Type / length
of the ethernet frame
a host may need to use this if it was aware of the destination host IP address but did not know there MAC address
why might a host need to use the
IPv4 Address resolution protocol (ARP)



