2530 virtual stack, LACP, and redundance

[LeifH]

Hi. 

I've got 3 HP J9773A 2530-24G-PoEP-switches and one Fortigate fw.

I was planning to set two of them in a stack connect them to a LACP interface to the fortigate-firewall with two interfaces pr stack-member connected, so if one of the switch dies the other will still work. The third switch should be connected with two fibre-connections to the stack as one trunk with one cable connected to each of the stack members. 

Is this possible?

I got a strange behavure (it didn't work proper to unplug trunk cables), and it felt like the stack of the 2530 was not as all a stack like I've done with Cisco and DELL-switches and the possiblitiles those switches give me.

the main switch in the stack had the config:

stack commander companyname
trunk 1-2 trk1 trunk (to the stack member)
trunk 3-4 trk2 lacp (to the firewall)
trunk 28 trk3 trunk (to the third switch)

one of the vlans:

vlan 28
name "production"
tagged 13-24,Trk1-Trk3
no ip address
exit

The config of the stack member:
stack join mac-address
trunk 1-2 trk1 trunk (to the stack commander)
trunk 3-4 trk2 lacp (to the firewall)
trunk 28 trk3 trunk (to the third switch)

one of the vlans:

vlan 28
name "production"
tagged 13-24,Trk1-Trk3
no ip address
exit

I did see that the trunk was working in terms of that the two switches did see each other and that the commander reported that the switch member was part of the stack.

Any input would be great. Thanks!

[Oliver Wehrli]

Hi,

I don't think that this is actually possible with the 2530 series. The virtual stack feature on these platforms is not to be confused with the actual stacking using dedicated stacking modules/cables, which is available on the 2920/3800 series.

The main difference is from my point of view that a virtual stack does not provide a distributed fabric across multiple switches. In that sense it only simplifies the management and reduces the number of IP addresses required for management purposes. But there is no single control plane across the switches. Applying this logic, I don't think that you can create dynamic link aggregations using LACP across multiple chassis. Remember the 2530 is an entry switching product, hence not really built for high-redundancy.

This is the link to the official documentation including virtual stacking on the 2530:
http://h20566.www2.hpe.com/hpsc/doc/public/display?sp4ts.oid=5333803&docId=emr_na-c04490665&docLocale=en_US
This might give you some insight in how you can troubleshoot your issue further - and most important of all, verify your virtual stack configuration.

I think there could be an easy test you can run to proof/disproof my theory. Just connect the fortigate appliance to a single switch and properly configure on both sides an LACP-based link aggregation (called Trunk on the 2530 side). If the link aggregation works properly on a single switch you can move one interface to the secondary switch in the virtual stack and apply the same configuration used before across the two stack members now. Please verify first, whether you correctly configured the virtual stack using the manual above.

I am trying to find confirmation of my theory, if successful I will share it here.

Regards,
Oliver

[LeifH]

Thanks.

I think your correct there, that these switches doesn't give me the stacking and features like the more proper ones, thus my issues. So my lacp is impossible the way I though. Will check next time I'm on-site, but it's gonna be a while before I'm onsite again.

[Oliver Wehrli]

Please keep us posted.

For your reference, you can use the the "Product Selector" available within the HPE Networking Online Configurator to filter for products that do support "proper" stacking.

Just go to http://h17007.www1.hpe.com/us/en/networking/products/configurator/index.aspx#.VpUfe3mFM-U  and

In the Ports | Features | Power tab you can simply tick the box for stacking under "High Availabilty" and you get a list of products supporting this kind of functionality. On all those products you are able to run LACP link-aggregations accross multiple switches in the stack.

Regards,
Oliver

[Vince-Whirlwind]

You basically have 2 choices to achieve active-active links between two switches and your firewall:

1. Stacking switches. Unfortunately, HP have long used the word "stacking" to refer to what is only management aggregation. Real "stacking" means multiple chassis being configured as a single viurtual switch. 2530s didn't used to stack. You needed 2920 or 3800. However I have heard that the newest 2530s *do* stack. Is this correct, anybody?

2. Distributed trunking. This creates a Trunk that aggregates endpoints that are on diverse switches. Unfortunately, you don't get this with 2530s, only with 3500s, 3800s, 5400s, 6200s, 6600s, 8200s.