day 1

switching mechanism

  1. process switching
  1. fast switching
  1. Csico Express Forwarding (CEF)

command

1.. no switchport in interface mode

Make the port as L3

"switchport mode access"

port type

  1. Trunking

Tagged with multiple Vlan

2, Access Port

Tagging means the header is insert between ffiled of the header

Different from encapsulation

Preprend the header infront of the original packet

config method

  1. auto negotiate
  1. Manual set the trunk

Based on dynamic trunking protocol

conf t

vlan 10

vlan 20

int f1/2

int f1/1

switchport mode access

switchport access vlan 10

interface vlan 20

interface vlan 10

swtichport mode access

switchport access vlan 20

ip address 10.1.10.1 255.255.255.0

ip address 10.1.20.1 255.255.255.0

STP

2 function

  1. Determine the best path
  1. to prevent layer 2 loop

3 type of scenario for flooding

  1. broadcast

unknown unicast

3.multicast

type of port

  1. Designated port

per segment/uplink

port offer shortest pth to root switch

  1. root port

per non-root switch/bridge

Elect based on shortest path to root switch