Ethernet Switching Features Flashcards
1
Q
Unmanaged Switch
A
- Standalone unit that can be added and run without configuration
- Often built into router and modem on SOHOs
2
Q
Managed Switch
A
- Switch settings can be configured
- If left unconfigured, acts as unmanaged switch
3
Q
Stackable Switch
A
- Can be connected and managed as one unit
4
Q
Modular vs Fixed Switch
A
- Modular switch has slots for plugins which can change number and types of ports
5
Q
Desktop vs rack-mounted Switch
A
- Smaller unmanaged switch weith 5-8 ports may be placed on desktops
- Larger switches are fitted to work in rack space
6
Q
MDI/MDI-X
A
- In 100BASE-T end system uses MDI to transmit on pins 1-2 and receive on 3-6 (uplink port)
- Switches use MDI-X Xand receives on 1-2 and transmits on 3-6
- Cable should be a Straight through (either T568A or B on both ends)
- Communication between switches would require crossover cable or dedicated uplink port(which has A on one end and B on the other)
- Most switches use auto-MDI/MDIX now which fixes this problem.
7
Q
MAC Address Table
A
- Switch learns MAC addresses by reading source MACs on port it receives it on
- If MAC cannot be found then switch acts as hub and transmits frame on all ports (flooding)
- Also referred to as CAM (content addressable memory) table
- Entries on table are flushed after a period of time
8
Q
Port Security
A
- Validates MAC address of end systesm that connect to switch port
- Usually you would not expenct MACs’ of devices to change often
- Two components:
- Specify a static MAC or allow port to accept certain number of addresses
- Specify an enforcement function which violation is detected (alert or shutdown port)
9
Q
Port Aggregation
A
- Combining two or more cabled links into single logical channel
- From host end can be call NIC Teaming
- Oftetn implemented with LACP (Link Aggregation Control Protocol)
- LACP is used to autonegotiate bonded link between swithc ports and end system
10
Q
Port Miroring
A
- Copies all packets sent to one or more source ports to a mirror destination port
- Used by packet sniffer, network analyzer of IDS(intrusion detection system).
- Ingress or egress traffic can be captured.
- Can be filtered based on protocl ID or TCP/UDP port number
11
Q
Jumbo Frames
A
- Allow for larger frames (up to 9000 bytes)
- Reduces amout of processing necessary by switches and routers
- Benefits are disputed
- Critical that all hosts and appliances on communications path are configured to suport them
12
Q
Flow Control
A
- Allows server to instruct switch to pause traffic temporarily
- Used to avoid overwhelming buffer and causing dropped frames
- IEEE 802.3x cannot distinguish between types of traffic
- CoS and QoS (Class and quality of Service) mechanisms can be allied to mark and police traffic
- PFC(priority flow control 802.1 Qbb) allows pause frames to apply to only certain traffic
13
Q
Show config
A
- CLI command for managed switch
- displays switches configuration
- can be used to compare changes to documentation
14
Q
Show interface
A
- CLI command for managed switch
- lists state of all interfaces or specified interface
- Identified by type, slot and port number
15
Q
802.3af
A
Power over Ethernet
-Up to 13 W over link
