IPv4 Addressinge.i)192.168.1.254/24 구간별 2진수 8자리 계산192 > 11000000168 > 101010001 > 00000001254 > 11111110 192.168.1 > network portion of address254 > host portion of address ClassFirst octectFirst octect numeric rangeA0xxx xxxx0-127B10xx xxxx128-191C110x xxxx192-223D (Multicast addresses)1110 xxxx224-239E (Reserved (experimental)1111 xxxx240-255 Loopback Addresses-> Address range 127.0.0.0 - 127...

Ethernet LAN Switching (Part2) ARP (Address Resolution Protocol):-> Discover Layer 2 address (MAC) of a known Layer 3 address (IP)-> consist of:- ARP Request: broadcast (sent to all host)- ARP Reply: unicast (sent to one host)-> cmd: arp -a-> cml: show arpInternet Address = IP AddressPhysical Address = MACType static = default entryType dynamic = learned via ARP   * Broadcast MAC address : FFFF...

Ethernet LAN Switching (Part1) PDUs; frame *preamble 과 SFD 영역은 Header로 생각되지 않음.*Minimum size for an Ethernet frame: 64 bytess ■ Header (8 bytes)Preamble (7 bytes)-> synchronize device's receiver clocks-> 10101010 * 7 SFD (1 bytes)->Marks the end of preamble, beginning of rest of the frame-> 10101011 Destination & Source (6 bytes)-> MAC address Type(Length) (2 bytes)-> 1500 or less, indicates LEN..

Introduction of CLICLI:interface you use to configure Cisco devices connect Cisco device:->Console port (USB Mini-B, RJ45)-> Rollover cable (!= cross over)  User EXEC Mode (limited) Priviledged EXEC Mode ->cannot change the configuration, but change time or save config files service password-encryption & secret-> enable service password-encryptioncurrent pw encryptedfuture pw encryptedenable sec..

OSI Model & TCP/IP Suite Networking model:categorize and provide a structure for networking protocols and standards ■ OSI Model-> conceptual model that categorizes and standardize different functions in NW Adjacent-layer interactionEncapsulation : 7 -> 1De-encapsulation : 1 -> 7Same-layer interaction1 - 1 or 2 -2 , 3-3... PDUs: Data + header +... 7 Application:-> closest to the end user-> intera..

Interfaces and CablesEthernet:-> collection of network protocols/standards-> defined in the IEEE 802.3 standard in 1983 Protocols:A set of logical rules defining how network devices and software should work (Ethernet, Cable, etc) Bits and Bytes (Speed is measured in bits per second (bytes X))1 kilobit (Kb) = 1,000 bits = 10^31 megabit (Mb) = 1,000,000 bits = 10^61 gigabit (Gb) = 1,000,000,000 bi..