port is access or trunk port

[getaway51]

Hi,

Is the port access or trunk mode? it has both config but which take precedence? 

What is the best command to verify?

switchport access vlan 10
switchport trunk encapsulation dot1q
switchport mode access

[Stefan E. · Accepted solution]

Hi,

in that case the Switch is an access Port.

Caused by this command: "switchport mode access"

Otherwise it has to be e.g. "switchport mode trunk"

You can check with

"show interface trunk" to see all trunks

or also "show interface Gi1/0/32 trunk" to check the Status:

Switch#sh int Gi1/0/32 trunk

Port Mode Encapsulation Status Native vlan
Gi1/0/32 off 802.1q not-trunking 1

Switch#sh int Gi1/0/46 trunk

Port Mode Encapsulation Status Native vlan
Gi1/0/46 on 802.1q trunking 2

Regards

Stefan

[Martin L]

show interface xyz trunk - good one; I forgot about that command; thanks!

[Martin L]

Port is an access Port due to switchport mode access

you should be able to get more info with show interface xyz switchport command

Regards, ML
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[getaway51]

Hi,

Does example below is a trunk or access port? It shows below 

Operational Mode: static access BUT Administrative Trunking Encapsulation: dot1q AND Negotiation of Trunking: On

I am confused whether it is access or trunk mode. Frm cfg, it looks like access port. Can I say Operational Mode: static access is confirm access port. Others no matter?

interface GigabitEthernet1/0/44
description Access Point
switchport access vlan 51
end

CMS03#sh int gi1/0/44 sw
Name: Gi1/0/44
Switchport: Enabled
Administrative Mode: dynamic auto
Operational Mode: static access
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: native
Negotiation of Trunking: On
Access Mode VLAN: 51 (172.1.8.24/28)
Trunking Native Mode VLAN: 1 (default)
Administrative Native VLAN tagging: enabled
Voice VLAN: none

[Martin L · Accepted solution]

You should always look at Operational Mode since a port state or mode depends on the other side of the link. Administrative mode means current or default config settings but you do not know what other side is doing; Dynamic auto mode seems to be default setting now for all switches (probably because of security). So, switch port waits for the other side; it could be trunking if the other guy asks for it (dynamic desirable or trunk mode). but not if both are dynamic auto, port is not-trunking. Note: some older L3 switches came with dynamic desirable by default.
Administrative Mode: dynamic auto and Operational Mode: static access seems to be default settings for switches now. Switch is set to have all ports as access ports by default. This idea comes from switch being set as a plug-and-play ready out of box (just connect devices). Note: Port is Access mode even thou you missing command switchport mode access.
Easier way to see if you port is trunking (or not) is with show interface trunk command.

Regards, ML
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