DTP Dynamic Trunking Protocol

switchport mode trunk
強制該接口成為Trunk並誘使對接口協商成Trunk

switchport mode access
強制該接口成為Access Port 並誘使對接口協商為Access Port

switchport mode Dynamic auto
設置該接口自動與對接口協商
------------------------------------------- 照過來左表是本文的重點哦
local | remote | result |
auto | access | access |
auto|auto|access
auto | trunk | trunk |
auto | desirble | trunk |
-------------------------------------------
switchport mode Dynamic desirable
設置該接口自動與對接口協商
------------------------------------------- 照過來左表是本文的重點哦
local | remote | result |
desirble | access | access |
desirble | trunk | trunk |
desirble | desirble | trunk |
desirble|auto|trunk
-------------------------------------------
cisco預設接口就為此模式
故當cisco交換器對接預設情況下會變為trunk

switchport mode nonegotiate
阻止接口發出DTP協商封包
但必須搭配指定access或trunk
一般建議使用此模式以減少出手意料的模式產生