ist 201 final 7-11.txt

technique 2 get packet on & off media

Ethernet, PPP, HDLC, & Frame Relay

in header & trailer, communication of nodes details, examples: frame start, addressing, type, quality, EC, frame stop

implemented in SW & HW, prepares packet 4 media travel & encodes as signals, framing, physical addys

LLC & MAC

IDs Network Layer protocol (IPv4/IPv6/IPX) used 4 frame

media sharing & topology

controlled & contention

deterministic, take turns, 4 ring topology, Token Ring

competitive, CSMA, 4 multiaccess logical topology, Ethernet & Wireless

CSMA/CD & CSMA/CA (CA 4 Wireless)

MAC 4 nonshared media, only consideration=1/2 or full duplex communication, doesn't require (physical?) addressing

point-to-point, multiaccess, & ring

logical connection between 2 devices within a network

adding the control info. (which differs by protocol)

Cyclic Redundancy Check, logical summary of frame contents 4 EC

Ethernet (802.2 & 802.3 4 LANs), PPP (4 WANs), & Wireless (802.11 4 LANs)

protocol 4 WANs, mocks point-to-point, uses PPP BC addy

4 Wireless (802.11), sends intention 2 send 1st

=48 bits

Wireless protocol frame field, IDs transmission station

2 types of bit encoding 2 place the bits on media

encodes binary digits into signals, HW-based

overhead (traffic) & interference (distortions)

bits 2 signals, grouping into patterns devices will recognize, has start & end codes in <- all sent in strings

time 2 generate 1 bit of data & send out as signal

amplitude (how high/strong), frequency (how often), & phase

NRZ & Manchester Encoding

signaling method with defined voltages 2 represent 1 & 0

uses voltage changes from high to low ( 0 ) & low to high ( 1 ) 2 represent 1 & 0

small group of bits representing larger groups

code group, for bits grouped into 5 bit symbol

capacity in given amount of time (theory)

capacity in given amount of time (practical - actual)

pairs 2 & 3 switched

Single-Mode (-----) & Multimode (xXxXx)

separating of light in fiber optic cables

802.11 (WiFi), 802.15 (WPAN & Bluetooth), & 802.16 (WiMAX)

a=5GHz, b=2.4GHz, g=2.4GHz, n=both

Optical Time Domain Reflectometer, 2 test fiber optic cables

indicate start & end of frame

802.2, soft, connects HW 2 upper layers

controls placement & removal of frames from media

Start Frame Delimiter, along with Preamble - synchronizes sending & receiving devices

updated Ethernet

technology used in switch networks, reason why 802.3ac came about - needed larger frame size

2 increase Ethernet frame 2 minimum size, "fill-in"

configures device 2 use specific MAC addy, fools

subscript/preceded with 0x

2 examine MAC addy

FF-FF-FF-FF-FF-FF

multicast group, 224.0.0.0 - 234.255.255.255 & begins with 01-00-5E

0-1-0-1 repetition (32-bit), after collision transmitting devices that collided continue transmitting 2 alert network devices of issue

devices stop transmitting 4 random time in response 2 collision

more devices, more access, & increased cable distances between devices

time 4 signal 2 propogate down cable

transmitting device sending 64 bytes of timing synchronization info.

with throughput speeds of 10Mbps /< each receiving device uses 8 bytes of timing info 2 synchronize receiving circuit

with 100Mbps /> no timing info - uses signaling methods 2 synchronize transmit & receive clocks

time required 4 bit 2 be placed & sensed on media, the faster the speed = the less time 2 react 2 collisions

maximum time 2 detect a collision, time 2 travel between 2 most distant devices * 2

time waited after successful transmission, 96 bit times

additional time waited (over interframe spacing) that collided devices must wait

physical differences of Ethernet

10Mbps - old Ethernet, Manchester Encoding

10Gbps Ethernet 4 future

logical point-to-point between 2 nodes in switch

frame buffer by switch when port unavailable

switch, MAC addys 2 ports, aka switch table

learning, aging, flooding, selective flooding, & filtering

IP addys 2 MAC addys

when router fakes being remote destination device

cmd 2 display/add/remove table entries

injecting network with wrong device MAC addy

work area, telecommunications room, horizontal (work 2 telecomm. rm - 90m max.), & vertical (backbone - telecomm. rm 2 equipment rm/LAN2LAN/2 ISP)

work area, < 6ft, 10m max (5+5)

Data Service Unit, transmission between backbone cabling & horizontal cabling

mini cables between patch panels & intermediate devices

2500m-a few km

pipe/duct 4 cabling

Media Dependent Interface, comps/servers/routers

Media Dependent Interface Crossover, hubs & switches

Channel Service Unit/Data Service Unit, 4 WANs - HW out of network - from network 2 ISP (?), Winchester connector

Data Communication Equipment, provides timing services, WAN access - provider end

Data Terminal, receiving timing services, WAN access - customer end, routers are DTE by default

4 remote management of router, modem connected 4 dialup access

several MBs, stored in flash, copied into RAM on startup

console, 2 connect 2 comp. with terminal emulation SW 4 initial configuration & also 4 troubleshooting

Virtual Teletype Interface, telnet/SSH 4 remote access CLI session, requires L3 addy on at least 1 interface, network services, & etc.

stored on NVRAM, loaded into RAM at startup = running-config

what's in RAM & changes when device configured, used 2 operate network device, lost on restart/off

user executive (> & known as view-only mode)

keyword argument

ambiguous (cmd?) , incomplete (cmd ?), & incorrect (^=?)

line console 0

enable password xxxxx

line vty 0 4

service password-encryption

banner motd #msg here#

interface VLAN1

! (receipt), . (timeout), U (unreachable)

from Win comp (as opposed 2 traceroute from IOS)

pic of overall network performance

cmd 2 list all devices in ARP cache (IP 2 MAC) , arp -d 2 clear cache

scanning method 2 collect MAC addys

cmd 2 show hosts connected 2 switch

review other cmds if time