A network engineer showed me the
show vlan output of an HP switch. I know tagged ports are trunk and untagged ports are access in Cisco terms. But can anyone explain the "no untagged port"? How is this used in real environments?
It means the "tagged" port does not also allow untagged frames. In the Cisco world, this is equivalent to having no native VLAN.
As a configuration command,
no vlan xy untagged n (or just
no untagged n when you're in the
vlan xy context) removes the VLAN
xy as untagged from port
n - so there's no untagged/native VLAN.
In Cisco speak that would be a trunk port without a native VLAN. In contrast to Cisco, on HPE switches you simply assign a VLAN as tagged or untagged to a port (with zero or one untagged VLAN per port). VLAN membership can also be learned dynamically if configured.