Test2 Review (part 2) Flashcards
What is DHCP?
Dynamic Host Configuration Protocol. Automatically assigns IP address, subnet mask, default gateway, and DNS server.
4 steps to obtain an IP address from DHCP server.
- Discover (client broadcasts a request for a DHCP server). 2. Offer (server replies with a suggested IP address). 3. Request (client accepts the offer & requests the IP). 4. Acknowledge (server acknowledges the request).
How does a proxy server operate?
Makes a request on behalf of a client. Clients are configured to forward their packets to a proxy server, which evaluates the request. If it has a copy of the info the client wants, it replies with the cached copy, otherwise the server forwards the request to the internet.
HUB vs switch
HUB: layer 1, each port on single collision domain, no switching table, collision occurs, data not secure, less expensive.
Switch: layer 2, each port on separate collision domain, switching table, no collision, data secure, more features, more expensive.
VLAN advantages.
Allows admins to group hosts into LANs to enforce access rights, etc. Cost & time reduction in migration of host from one group to another. Security - users in other groups will not receive messages that weren’t meant for them. Allows creating new virtual workgroups.
Power over ethernet (POE)
Supplies electrical power over ethernet connections. IEEE 802.3af. Requires cat 5 or better.
What is a broadcast storm?
A broadcast storm is an abnormally high number of broadcast packets within a short period of time.
Communication principles.
An antenna attached to electrical circuit allows electromagnetic waves to be broadcast & received by a receiver some distance away.
Speed of electromagnetic waves in a vacuum.
180000 miles/sec (300000 km/sec)
Speed of electromagnetic waves in a copper wire.
2/3 of speed in a vacuum.
Long wave communication distance & kHz.
<30 kHz used to communicate across the globe. Can also penetrate saltwater to depths of 100’s of feet.
Short wave communication distance & MHz.
Generally 3-30 MHz (10-100 meters).
Cat 3 maximum distance & data rate
Distance = 100 meters, data rate = 10 Mbps
Cat 5 maximum distance & data rate
Distance = 100 meters, data rate = 100 Mbps
Cat 5e maximum distance & data rate
Distance = 100 meters, data rate = 1 Gbps
Cat 6 maximum distance & data rate
Distance = 100 meters, data rate = 1 Gbps
Cat 6a maximum distance & data rate
Distance = 100 meters, data rate = 10 Gbps
Cat 7 maximum distance & data rate
Distance = 100 meters, data rate = 10 Gbps
Ethernet frame minimum size. Also, what else is needed in the frame to transmit data.
Min size = 64 bytes. Source and destination addresses (MAC or physical) needed
Ethernet bandwidth capacity
10 Mbps
Fast ethernet bandwidth capacity
100 Mbps
Gigabit ethernet bandwidth capacity
1 Gbps
10-gigabit ethernet bandwidth capacity
10 Gbps
100-gigabit ethernet bandwidth capacity
100 Gbps
VPN concentrator
a type of networking device that provides secure creation of VPN connections and delivery of messages between VPN nodes. It is a type of router device, built specifically for creating and managing VPN communication infrastructures.
What is VOIP?
Voice over IP - digitizes voice traffic so it can be treated like other data on a network.
What is a call agent (VOIP component)?
Maintains a network’s dial plan (routes)
What is PSTN (VOIP component)?
Public switched telephone network
What is RTP (VOIP component)?
Real-time transport protocol that can carry voice & data in real-time
What is SIP (VOIP component)?
Session Initiation Protocol - establishes a VOIP phone call.
What is PBX (VOIP component)?
Private Branch Exchange
Well-known port numbers
0-1023
Registered ports
1024-49151
Ephemeral (short-lived) ports
49152-65535
ICMP definition & layer
Internet control message protocol. Used for managing & testing layer 3 functionality. Layer 3
ARP definition & layer
Address resolution protocol. Allows determining MAC address from IP address. Layer 3
DHCP definition & layer
Dynamic host configuration protocol. Configures hosts automatically with IP address & other info. Layer 2
IETF definition
Internet engineering task force. Identifies operational problems & proposes solutions.
IAB definition
Internet architecture board
IRTF definition
Internet research task force. Focuses on long-term research on protocols, apps, architecture, & technology
ICANN definition
Internet corporation for assigned names & numbers.
