Dynamic Trunking Protocol (DTP)

DTP is a Cisco proprietary Point-to-Point Protocol# used between Switches# for automatic trunk# negotiation. Depending on modes set on both end, DTP can decide whether the link should be trunk or non-trunk. The following table shows the outcome for the link for different composition of opposite ports.

	Dynamic Auto	Dynamic Desirable	Trunk	Access
Dynamic Auto	Access	Trunk	Trunk	Access
Dynamic Desirable	Trunk	Trunk	Trunk	Access
Trunk	Trunk	Trunk	Trunk	Not recommended
Access	Access	Access	Not recommended	Access

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TRS2251 Chapter 9: VLANs

Dynamic Trunking Protocol (DTP)
Cisco Switch Configuration

To configure #Virtual LAN (VLAN) with Switch#, there is a need to set up an IP Address, subnet mask, and default gateway (router to direct switch management traffic for remote access such as Telnet and Secure Shell (SSH)) in a switch. The configuration could be done in IOS# with the command vlan {number} in Interface Configuration Mode follows by the IP address assigned to the VLAN. We can attach a name to a VLAN by simply running the command name {vlan-name} right after vlan {number} command in Global Configuration Mode. Define the VLAN membership mode for the assigned interface (port) as access (see Dynamic Trunking Protocol (DTP)# for other possible modes) with switchport mode {mode} and assign VLAN to it by switchport access vlan {number} in the Interface Configuration Mode.

#networking #p2p