Hello,
I suppose your switch is running latest 2.1-r5 release. The following commands configure port 5 for access port in vlan 2:
1) Remove port 5 from vlan 1
cnMatrix-demo# config terminal
cnMatrix-demo(config)# vlan 1
cnMatrix-demo(config-vlan)# no port gig 0/5 unta gi 0/5
cnMatrix-demo(config-vlan)# exit
2) Add port 5 as untagged into vlan 2
cnMatrix-demo(config)# vlan 2
cnMatrix-demo(config-vlan)# port add giga 0/5 untag gig 0/5
cnMatrix-demo(config-vlan)# exit
3) Set native (pvid) vlan to vlan 2, and set mode to access
cnMatrix-demo(config)# interface giga 0/5
cnMatrix-demo(config-if)# switchport pvid 2
cnMatrix-demo(config-if)# switchport acceptable-frame-type untaggedAndPrioritytagged <<<< Only needed for 2.0.5-r2 release
cnMatrix-demo(config-if)# switchport mode access
% Warning: Acceptable frame type was automatically set to "untaggedAndPriorityTagged".
cnMatrix-demo(config-if)# end
Using GUI:
Layer 2 Management->VLAN->Static VLANs page: 1) Remove Giga0/5 from the 'Member Ports' and 'Untagged Ports' fields in VLAN 1. Click Apply. 2) Add Gi0/5 into 'Member Ports' and 'Untagged Ports' fields in VLAN 2. Click Apply.
Layer 2 Management->VLAN->Port Settings page: Select port 0/5, Change PVID to 2. Click Apply.
Layer 2 Management->Port Manager->Basic Settings page: Select port 0/5 and choose Access from the pull-down menu of the 'Switch Port Mode'. Click Apply.
Thanks.