HP 1920 Ring Topology with 3 switches

[Jonboy-74]

Hello,

I have been presented with a configuration that I believe is incorrect, and am seeking guidance to confirm or reject my suspicion.

I've always been of the opinion that switch port uplinks to other switches, router, and firewalls should be Trunk (I come from a Cisco background). Additionally, I've lived under the asumption that in the HP world of hybrid ports that Hybrid really are just for endpoint devices where you need (for example) a phone and a PC to share the same port; is this a correct or incorrect assumption?

Additionally, aside from potentially changing the uplink connections from Hybrid to Trunk, are there any other considerations for maintaining the ring topology or guidance to move away from the Ring topology?

There are 3 HPE OfficeConnect 1920 switches (all JG928A) physically connected in a Ring Topology. Pertinent information is as follows:

Switch names:

HP-1920-MDF1
HP-1920-MDF2
HP-1920-IDF

Physically, the switches are connected as follows:

MDF1 Gig 1/0/1 is connected to MDF2 1/0/1
MDF1 Gig 1/0/2 is connected to IDF Gig 1/0/1
MDF1 Gig 1/0/4 is connected to IDF 1/0/2
IDF Gig 1/0/4 is connected to MDF2 Gig 1/0/3

Switchport configuration is as follows:

MDF1:

interface GigabitEthernet1/0/1
port link-type hybrid
port hybrid vlan 100 999 tagged
port hybrid vlan 1 untagged
port auto-power-down
poe enable
stp edged-port enable
#
interface GigabitEthernet1/0/2
port link-type hybrid
port hybrid vlan 100 999 tagged
port hybrid vlan 1 untagged
port auto-power-down
poe enable
stp edged-port enable
#
interface GigabitEthernet1/0/4
port link-type hybrid
port hybrid vlan 100 tagged
port hybrid vlan 1 untagged
port auto-power-down
poe enable
stp edged-port enable

MDF2:

interface GigabitEthernet1/0/1
port link-type hybrid
port hybrid vlan 100 999 tagged
port hybrid vlan 1 untagged
port auto-power-down
poe enable
stp edged-port enable
#
interface GigabitEthernet1/0/3
port link-type hybrid
port hybrid vlan 100 999 tagged
port hybrid vlan 1 untagged
port auto-power-down
poe enable
stp edged-port enable

IDF:

interface GigabitEthernet1/0/1
port link-type hybrid
port hybrid vlan 100 999 tagged
port hybrid vlan 1 untagged
port auto-power-down
poe enable
stp edged-port enable
#
interface GigabitEthernet1/0/2
port link-type hybrid
port hybrid vlan 100 999 tagged
port hybrid vlan 1 untagged
port auto-power-down
poe enable
stp edged-port enable
#
interface GigabitEthernet1/0/4
port link-type hybrid
port hybrid vlan 100 999 tagged
port hybrid vlan 1 untagged
port auto-power-down
poe enable
stp edged-port enable

[parnassus · Accepted solution]

Hello, I would suggest you another approach: get rid of the link between MDF1 and MDF2 switches and enhance downlink resiliency between IDF and, respectively, each MDF switch by using a Links Aggregation (a LAG between IDF and MDF1 and another LAG between IDF and MDF2).

Get rid of Port Link of type Hybrid.

You have to consider that an interface - physical or logical (as a LAG), doesn't matter - carrying (if necessary) more than one VLAN (more than its PVID) should be set of type Trunk..and in HPE OfficeConnect 1920 Comware 5 jargon/terminology "Trunk" means exactly what it means in Cisco world (a LAG instead is an EtherChannel).

So to summarize and assuming you're starting from a port default state:

1. On IDF Switch create two LAGs - say LAG 1 and LAG 2 - with two (or more) physical interfaces each one.
2. Set the IDF LAG 1 to carry required VLAN IDs to MDF 1 Switch's LAG 1 (generally there is a PVID = Untagged and one or more VLAN ID as tagged).
3. Do the same (to match) on the MDF 1 Switch (MDF 1 Switch will have LAG 1).
4. Set the IDF LAG 2 to carry required VLAN IDs to MDF 2 Switch's LAG 1 (generally there is a PVID = Untagged and one or more VLAN ID as tagged)
5. Do the same (to match) on the MDF 2 Switch (MDF 2 Switch will have LAG 1).
6. Connect IDF cables between LAG 1 (IDF) and LAG 1 (MDF 1), connect cables between LAG 2 (IDF) and LAG 1 (MDF 2)
7. Ensure STP is enabled and properly configured on IDF, MDF 1 and MDF 2 switches (use RSTP).

If so (STP is OK) you can eventually interconnect again MDF 1 and MDF 2 with a single link as a sort of backup link in case MDF 1 or MDF 2 will be disconnected by IDF (this inter-switch link will be automatically blocked by STP, this is correct and expected).

[Jonboy-74]

Thanks Parnassus,

I don't have that many ports available on the IDF, but I get what you're driving at with the LAG idea. At this point I was considering just dropping one of the IDF connections an making everything a Trunk port between the switches. Thanks for the clarification.

In your experience, what purpose does the Hybrid port really serve? Just for VoiceData ports as I mentioned, or anything else?

Thanks,

Jonboy

[parnassus]

Hello Jonboy,

Start here and have a read here too (in particular what Richard Lichtfield wrote): if you're not dealing with VoIP phones - so you aren't dealing with access ports (and you aren't on your uplink ports) - then the trunk operating mode is the way to go on HPE OfficeConnect 1920 Switch Series (which is Comware 5 OS based).

Also consider that newer HPE OfficeConnect 1920S Switch Series that superseded the older HPE OfficeConnect 1920 Switch Series (and the same can be said about all HP ProCurve ProVision OS based switch series some of them now rebranded as HPE Aruba ArubaOS-Switch OS based switch series) has no concept of "hybrid" port.