When Is A Trunk Not A Trunk?

Very good article here – http://networkingnerd.net/2011/02/02/when-is-a-trunk-not-a-trunk/

Particuly like setting of Native vLAN and tagged networks over an HP trunk;

So, if HP refers to an uplink carrying multiple VLANs are a tagged port, then does HP have a “trunk”? In fact they do. In HPvania, a trunk is a logical construct that aggregates multiple ports into one logical link. For those of you that might be out there scratching your heads about this one, this means that when you “trunk” a group of ports on an HP switch, you are creating one LACP link from up to four individual ports. This kind of configuration should look like this:

Switch(config)#trunk 19-24
Switch(config)#trk1
Switch(config-trk)#lacp
Switch(config-trk)#vlan 1
Swtich(config-vlan)#untagged trk1
Swtich(config-vlan)#vlan 10
Swtich(config-vlan)#tagged trk1
Swtich(config-vlan)#vlan 99
Swtich(config-vlan)#tagged trk1

Those of you that are fans of irony will appreciate that the above config sets up this LACP port aggregation to pass multiple VLANs to another switch. In other words, we are configuring a Cisco “trunk” on top of an HP “trunk”.

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