This value specifies which network protocol, such as ip, ipx, at (AppleTalk), or ipv6 at layer 3, or llc, snap, and ethernetii encapsulation types at layer 2, this protocol-based VLAN entry matches traffic against. An admin sets this when defining a rule that assigns untagged traffic to a VLAN based on its protocol, such as separating IPX traffic from IP traffic onto different VLANs on a shared port. Setting hh3cProtocolVlanProtocolType to ip means the associated entry classifies IP traffic into the VLAN identified by hh3cProtocolVlanVlanId.