HP VLAN Tagging Terminology Differences Defined
HP Procurve switches have four VLAN modes; "Untagged", "Tagged", "No", and "Forbid". Untagged mode is the equivalent of Access Mode in Cisco IOS terminology, which is used for end points, or devices not passing VLAN traffic forward (such as client ports; desktops, printers, etc.). Tagged mode is the same as Trunk mode in Cisco, which is used for ports that connect devices and are passing traffic forward (uplink or downlink ports on a switch or router). No mode means the physical port is not a part of the VLAN. Forbid mode restricts the port you added from communicating with that VLAN, regardless of any other tag setting.
The term Trunk means two different things when dealing with HP or Cisco equipment, so use this term with caution. HP Procurve switches use "trunk" to define a group of physical Ethernet ports, you trunk VLAN's from one phyical port to another, Cisco calls this a channel-group. Cisco uses VLAN trunk as a basic term to define what HP Procurve calls a Tagged port.
Both devices use 802.1Q standard VLAN identification. Older HP Procurve switches which are quite common, such as the HP Procurve 4000m, could only support a maximum of 8 VLANs. This basic feature when enabled, can add a little more functionality to an otherwise outdated, simple 10/100 switch. To enable VLAN support on your 4000m, you can easily telnet into the device, login as a manager, and turn on VLAN Support from the menu (it does require a reboot on these older switches). Today, you can setup up to 256 VLANs on a single modern HP Procurve switch (or router), however, a centrally located device, can pass (store) the tags of up to 4096 VLAN ids. VLAN 1 is the default administrative VLAN, this is set as "Untagged" on all ports out of the box. I generally leave it untagged on at least each uplink port, this save you from a tag mismatch conundrum (you may only have one VLAN in "untagged" in HP Procurve speak (access in Cisco speak) on any one port, which more or less requires every other VLAN to be "tagged" ("trunked" in Cisco speak) and passed on to the the next switch or router on an uplink port.
HP Procurve switches allow up to 32 characters for the description, when you're looking at it in the menu view however, it will be truncated to 12 characters, so first 12 characters should begin with different descriptors so that there is some immediate distinction here. Typically, when I name them, I'll either call them the building or location they are located at, plus the number ID, e.g. building12. It's good to have both pieces of physical and virtual information to save yourself some confusion, and early on, so if you're viewing them in the trunicated view, you'll be able to quickly distinguish the difference.
Final words of wisdom, keep it simple, and avoid "spaghetti VLAN's". Feel free to contact us for consultation or advice with your HP and Cisco integration, we have years of experience building networks with both HP and Cisco equipment. Remote support is available and we have the ability to contract onsite.