HP Switch Model: E2620 virtual stack and LACP across different devices

[bda2206]

Hello all,

we have 2x E2620 48port POE switches.  

in front of this we have a Sophos UTM cluster, with a LAG configured on 2 ports. For the LAG to operate correctly I want to configure 2x LAGs on the switches, for example port 2 on both switches as LAG1 and port 3 on both switches to be a second LAG. 

Is this possible with the virtual stack that these switches offer? Do I need to buy any additional components, or can I just use a GB port to virtually stack them?  Theres only 10-15 users + phones, so no concerns about bandwidth.

thanks in advance.

Brian

[parnassus · Accepted solution]

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bda2206 wrote: we have 2x E2620 48port POE switches. in front of this we have a Sophos UTM cluster, with a LAG configured on 2 ports. For the LAG to operate correctly I want to configure 2x LAGs on the switches, for example port 2 on both switches as LAG1 and port 3 on both switches to be a second LAG. 

Is this possible with the virtual stack that these switches offer? Do I need to buy any additional components, or can I just use a GB port to virtually stack them?  Theres only 10-15 users + phones, so no concerns about bandwidth.

HP 2620 doesn't support any Virtual Stacking technology/feature (nor virtual stacking deployed using frontplane ports neither virtual stacking deployed using backplane dedicated stacking modules) so if you interconnect your two 2620 they will remain two separate logical entities...so you can't terminate an originating (on Sophos UTM) LAG made with two links into two ports, respectively owned, each one, by one 2620...the terminating LAG can't exist (since can't be logically distributed to two non logically stacked Switches)...if you try I doubt it works (at best you will form an evident loop).

The only way to terminate correctly an originating (on Sophos UTM) LAG made with two or more links is to use Switches virtually stacked at other end (Software VSF on frontplane stacking or Hardware Backplane Stacking on ArubaOS-Switch operating system based Switch series or using IRF virtaulization switching technology available on HPE FlexNetwork Switch Series) so LAG can be created there too spanning over physical ports of different Switches that are part of a single logical Virtual Switch.

If, instead, on Sophos UTM you can create two separate LAGs (of separate non overlapping logical Subnets, let me say Port 1+2 for LAG1 and Port 3+4 for LAG2, LAG1 and LAG2 are, from the point of view of downling devices, as two separate entities) and terminate them on respective LAGs on Switch 1 and Switch 2 (eventually interconnected together, no loop here due to LAG1 and LAG2 on Sophos UTM behave like two separate Switches without inter-Routing/inter-Forwarding capabilities).

[bda2206]

belatedly, many thanks for the response. My switches have an option to virtually stack in the web interface. I'll activate that and see what happens.