Determine trunk/access and tag/untag in HPE SW

[longtrancntt]

Hi all,

I'm new to HPE product and the concept of trunk/access and tag/untag of HPE SW makes me confused. Currently, I have 2 products: the HPE 1920 and the other is HPE 2530.

1. The config of Trunk port in HPE 1920: 
   
   • Untagged membership: 1
   • Tagged membership: 2-4094
   • Link-type: Trunk
   • PVID: 1
2. The config of Trunk port in HPE 2530 (I choose port 24 as a Trunk port):
   • Untagged membership: 1-23,25-28,Trk24
   • Tagged membership: None
   • Link-type: Trunk (actually this option is not showed/available)
   • PVID: 1 (actually this option is not showed/available)

As I see there is an opposite different between 2 configs:  1920 is using VLAN to setup trunk/access, and 2530 is using Port? 

In 2530, if I want to make port 24 to become Trunk and will allow every VLAN to go through it to Router => What should  I need to do with this port in configuration? And, how if I want to allow only 1 VLAN can go through a port (example: port1 will only allow VLAN2 to go through it.)

Can please explain the detail of the tag/untag concept? Is it the same with trunk/access? And do I need to config both tag/untag with trunk/access to allow/deny VLAN to go to client?

Thank you very much.

[Emil_G · Accepted solution]

Hello, 

It is important to know that 1920 and 2530 belong to different families of HPE switches with different origin and history. They are running very different operating systems, some terms have different meanings and things are configured different way. Especially confusing is the term "trunk"

1920 uses the terminology that is also used by other vendors. Trunk port is a port that carries multiple tagged VLAN and one untagged (the native VLAN or the PVID). Access port is a port that only supports a single untagged VLAN.

2530 doesnt use the concept of trunk and access port. Trunk here means something completely different not related to VLAN tagging:  a logical interface which combines multiple physical interfaces for load sharing and redundancy. Other vendors call this link-aggregation, LAG, port-channel etc. 1920 calls it bridge-aggregation.

When it comes to VLAN configuration, the ports and trunks of the 2530 can be configured as tagged or untagged members of a VLAN. The port can be an untagged member of only one VLAN and tagged member of multiple VLANs, exactly as with the trunk, the same principle only it is not called trunk. Every port has be member of at least one VLAN, it can be tagged or untagged. By default all ports are untagged in VLAN 1. 

So if you want to connect port 24 of 2530 to the 1920 and you want to have matching VLAN configuration here is what you can try.

First remove Trk 24 with the following command. You dont need a trunk here.

HP2530(config)# no trunk 24

Then assign the VLANs to port 24 with the following commands

HP2530(config) interface 24 untagged vlan 1

HP2530(config) interface 24 tagged vlan 2-10

The second command doesnt allow you to specify all the VLAN like it can be done in the trunk configuraiton of 1920. You have precisely to specify for which VLANs the port will receive and send tagged traffic. Here in the example this are all VLAN numbers from 2 to 10.  The VLANs must exist on the switch.

How will this port behave with this configuration.

Inbound traffic: Packets that arrive on port 24 without VLAN tag will be assigned and forwarded to receivers in VLAN 1.  Packets that arrive with VLAN tag ID of 2, 3, 4, 5, 6, 7, 8, 10 will be assigned to the respective VLAN. Packets that arrive with VLAN tag but ID different than the configured VLANs will be dropped. 

Outbound traffic: If packet has to be sent out this port to a receiver in VLAN 1 it will be sent without a VLAN tag. If packet has to be sent to a receiver in VLAN 2 for example, it will carry a VLAN tag with ID 2. Packets to receivers in VLANs different than 2 to 10 cannot be sent via this port.