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Webcast-Catalyst9k
New Member

switchport modes

Can anyone list these and please explain what each does, i'e access mode, trunk mode, dynamic, and desirable etc

thanks

2 REPLIES
Bronze

Re: switchport modes

Hi.

This are few method which enable DTP ( dyanamic trunking protocol) ,

If the access keyword is specified, then the interface is configured as an access port and trunking is disabled, which is equivalent to the DTP mode of off. If the dynamic keyword is specified, a DTP mode of auto or desirable can be selected by configuring the appropriate keyword. By default, all interfaces are configured to operate in a DTP mode of desirable, i.e., switchport mode dynamic desirable. Finally, if the trunk keyword is specified, this forces the interface to trunk unconditionally, which is equivalent to a DTP mode of on. If the trunk keyword is specified, you can also optionally use the switchport nonegotiate interface configuration command to force the DTP mode for the interface to nonegotiate.

Please refer attached document for more information, rate this if this helpful

Minu

Silver

Re: switchport modes

Let's start:

switcport mode access - only on VLAN is supported over this port

switcport mode trunk - set the port to trunk in static mode, there is no communication between the switch like in dynamic mode. Over trunk you can transfer multiple VLANs traffic.

switcport mode dynamic desirable - dynamic mode can the switch communicate with other end about the port role - functional as trunk or access - desirable start the conversation (it's kind of master in the communication), if the other end is desirable or auto trunk will be formed anyway no

switcport mode dynamic auto - te switchport just wait for the incoming DTP (dynamic trunking protocol) messages, since of this two port in auto mode never form trunk.

switchport mode trunk - switchport mode trunk

......................- switchport mode dynamic auto

......................- switchport mode dynamic desirable

result is TRUNK!

switchport mode dynamic auto - switchport mode trunk

......................- switchport mode dynamic desirable

result is TRUNK!

switchport mode dynamic auto - switchport mode dynamic auto

not form TRUNK!

Use trunk lines when you want to transfer more than one VLAN traffic over one line (frames are tagged with VLAN id, except in case of 802.1q native VLAN).

bye

FCS

Please rate me if I helped.

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