knowledge

• tcpdump options

  • -c: the number of packets captured
  • -i interface: set the interface on which tcpdump will moniter
  • -n: show address in number format, not hostname.
  • -nn: in addition to -n, show port in number format, instead of service name
  • -P: set the diretion of captured packets. available values are in, out, inout
  • -s len: set the length of captured packets. default is 65535byte
  • -t: no timestamp in every output
  • -tt: show not fomatted time in every output
  • -r: read data from file

• CSMA (Carrier Sense Multiple Access)

  • Medium Access Control Protocol, in Data Link Layer
  • CSMA/CD is used in wired network, and CSMA/CA is used in wireless network

• 10base5

  • 10Base5 is a type of standard for implementing Ethernet networks. 10Base5 is sometimes referred to as thicknet because it uses thick coaxial cabling for connecting stations to form a network. Another name for 10Base5 is Standard Ethernet because it was the first type of Ethernet to be implemented.

  • 10Base5 supports a maximum bandwidth of 10Mbps, but in actual networks, the presence of collisions reduces this to more like 4 to 6 Mbps. 10Base5 is based on the 802.3 specifications of Project 802 developed by the institute of Electrical and Electronic Engineers(IEEE).

  • 10Base5 refers to a standard for Ethernet network techologies that use a thicker version of coaxial cables. It has the capability to transmit data at speed of 10Mbps up to 500 meters using baseband transmission. 10Base5 is also known as Thicknet, ThickWire, thick Ethernet and thick coaxial Ethernet.

• in question: being considered or discussed.

• aarf is a rate control algorithm.