_Thomas_ wrote: On all interfaces of the core switch i've applied the command broadcast-suppression percent 25.
Do you mean 25% (of a 1Gbps interface)? probably a too high value...then you should also pay attention to the admitted values (granularities) in terms of - if I recall correctly (you should check on your exact Comware based Switch documentation, generally the "Layer 2 - LAN Switching Configuration Guide") - integer multiple of the minimum accepted 64 (pps/bps) value.
AFAIK broadcast-suppression command admits ratio, pps (packet per second) max-pps or kbps (kilo bit per secon) max-kbps value as argument for any given interface (uplinks too), so broadcast-suppression { ratio | pps max-pps | kbps max-kbps}, the same approach is valid also for multicast-suppression and unicast-suppression.
Apart from official Switch's Documentation/Release Notes (to keep as references), this KB Article could be an interesting reading too (HPE Community has a lot of topics about Broadcast/Storm suppression).
I'm not an HPE Employee
I fear there isn't a single valid answer (nor I found an official Best Practice HPE Guide/KB Article about it despite the argument of broadcast/unicast/multicast storm suppression - plus other similar features regarding ARP flooding - is discussed on official HPE switch series documentation): it depends on the type of storm you need to fight against and your network characteristics (knowing nothing about how many pps or kbps the storm can generate and the type of traffic the storm will be formed of...the only reasonable thing to do is starting with restrictive suppression values and fine tune them along the way...say starting with - as example - 128 or 256 pps - restrictive - up to 1024 or 2048 pps - less restrictive - threshold values).
Possible useful threads: here, here and here.
I'm not an HPE Employee