Module 3: Networking Devices Flashcards
What does a network adapter do?
Also called a network interface card, or NIC, connects a host to the network medium. It is responsible for converting binary data into a format that can be sent on the network medium.
What does a transceiver do?
It’s responsible for converting digital data into digital signals to be sent on the medium. The type of signal the transceiver sends depends on the type of network. A fiber optic NIC sends light signals, a wired NIC sends electronic signals on a wire, and a wireless NIC sends radio signals. To receive signals, the transceiver converts digital signals from the network to digital data for the PC.
What does a modem do?
Converts binary data to analog waves on the sending end (modulation) and then converts the analog waves back to binary data on the receiving end (demodulation).
Network adapters use what layers of the OSI model?
layers 1 and 2.
True or False:
The type of network adapter you choose must match the network architecture you are connecting to.
True.
Describe a GBIC Transceiver module.
A GBIC (gigabit interface converter) is a large transceiver that fits in a port slot and is used for Gigabit media, including copper and fiber optic.
Describe a SFP Transceiver module.
An SFP (small form-factor pluggable) is similar to a GBIC, but is a smaller size. An SFP is sometimes called a mini-GBIC.
Describe a SFP+ Transceiver module.
SFP+ is a newer version of the SFP. SFP+ supports data rates as high as 10 Gbit/s, 8 Gbit/s Fibre Channel, 10-gigabit Ethernet, and the Optical Transport Network standard OTU2.
Describe a XFP Transceiver module.
An XFP transceiver is similar to an SFP in size, but is used for 10-Gigabit networking.
Describe a QSFP Transceiver module.
QSFP (quad, or 4-channel, small form-factor pluggable) is a compact hot-pluggable transceiver that is also used for data communication applications.
What is a Media Converter?
- A media converter is used to connect network adapters that are using different media types. For example, a media converter could be used to connect a server with a fiber optic Ethernet NIC to a copper Ethernet cable.
- Media converters only convert from one media type to another within the same architecture (such as Ethernet). A media converter cannot translate between two different architectures. This must be done using a bridge or a router. Converting from one architecture to another would require modifying the frame contents to modify the Data Link layer address.
What level does a media converter work at in the OSI model?
Layer 1, the physical layer. Media converters do not read or modify the MAC address in any way.
What is a MAC address?
- A MAC address is a unique identifier burned into the ROM of every Ethernet NIC.
- The MAC address is a 12-digit (48-bit) hexadecimal number (each number ranges from 0–9 or A–F).
The address is often written as 00-B0-D0-06-BC-AC or 00B0.D006.BCAC (dashes, periods, and colons can be used to divide the MAC address parts). - The MAC address is globally unique by design. The first half of the MAC address, the first six digits, is assigned to each manufacturer. The manufacturer determines the rest of the address, assigning a unique value that identifies the host address. A manufacturer that uses all the addresses in the original assignment can apply for a new MAC address assignment.
- Devices use the MAC address to send frames to other devices on the same subnet.
What is an ARP and what does it do?
Stands for Address Resolution Protocol.
- Hosts use ARP to discover the MAC address of a device from its IP address. Before two devices can communicate, they must know the MAC address of the receiving device. If the MAC address isn’t known, ARP does the following to find it:
1. The sending device sends out a broadcast frame.
- The destination MAC address is all Fs
(FFFF:FFFF:FFFF).
- The sending MAC address is its own MAC address.
- The destination IP address is the known IP address
of the destination host.
- The sending IP address is its own IP address.
2. All hosts on the subnet process the broadcast frame, looking at the destination IP address.
3. If the destination IP address matches its own address, the host responds with a frame that includes its own MAC address as the sending MAC address.
4. The original sender reads the MAC address from the frame and associates the IP address with the MAC address, saving it in its cache.
Once the sender knows the MAC address of the receiver, it sends data in frames addressed to the destination device. These frames include a cyclic redundancy check (CRC), which is used to detect frames that have been corrupted during transmission.
What is a RARP?
Reversed ARP.