Hi Ben,
What happens to the traffic on an access port if the associated VLAN is deleted?
The port formally remains in the associated access VLAN, but because that VLAN does not exist anymore, all received traffic is dropped on arrival (essentially, it goes nowhere - it gets blackholed), and no traffic is sent out from this port.
How does a switch treat the traffic if the port is configured as an access port but no VLAN is specified?
On switches that support VLANs, there is no such thing as a "port without a specified VLAN". Every port must be associated with a VLAN. A port that does not display the switchport access vlan command in its configuration is in fact a port in VLAN1, and the command does not show up because it is the default setting. Try entering switchport access vlan 1 - this command won't be visibly added to the configuration because it is the default setting. It can actually be kind of unsettling if your access VLAN on a port was different from 1, then you set it explicitly to 1, and the whole switchport access vlan command just disappears.
Best regards,
Peter
