This article briefly explains how to integrate a HP Procurve and Cisco in one network, and make sure the VLANs are correctly routed across the two switches. I avoid using the term "trunk" as the definition of a "trunk" differs greatly between Cisco and HP: a trunk on a HP Procurve refers in fact to a feature like Cisco's EtherChannel, something entirely different.
Multi-port trunking is also outside the scope of this article, but the basics remain the same.
For both switches, you first need to define the required VLANs. Take a look at the switch documentation if you don't know how, as this is outside the scope of this article.
To explain more easily, consider the following scenario:
This is only an example: adjust accordingly to your own situation!
On the Cisco switch, configure the uplink port as a trunk, and, if necessary, allow the required VLANs on it. Optionally, configure STP and/or any other options, if needed:
Sw1(config)# interface Gi0/1 Sw1(config-if)# switchport mode trunk Sw1(config-if)# switchport trunk allow vlan 10,15,20 Sw1(config-if)# no shut
If you don't want to limit VLANs on the trunk, you can omit the third statement, in which case all VLANs will be allowed to pass through the trunk.
HP works differently by directly specifying VLANs on a port as tagged, untagged, or excluded:
|tagged||The specific VLAN is allowed on the port, and is tagged.|
|untagged||The specific VLAN is allowed on the port, but will not be tagged. This is similar to Cisco's "Native VLAN" on a trunk port.|
|excluded||The specific VLAN is not allowed on the port (traffic is blocked).|
To configure the uplink port on the HP switch, we need to emulate a trunk port by setting all allowed VLANs as tagged on that port. VLANs that are not allowed to pass through are set to excluded.
Unlike Cisco, where we work at the port level, on HP Procurve, we start at the VLAN level.
Sw2(config)#vlan 10 Sw2(Vlan-10)#tagged 1 Sw2(config)#vlan 15 Sw2(Vlan-15)#tagged 1 Sw2(config)#vlan 20 Sw2(Vlan-20)#tagged 1