That’s interesting. We had the exact same problem with our F5s: bulkwalk with the default bulksize of 10 resulted in a timeout while a size of 5 worked. I didn’t try 9 or 8. Maybe that would work, too.
Either way, I added a rule WATO → Host & Service Parameters → Access to Agents → Bulk walk: Number of OIDs per bulk and set it to 5 for my F5 devices.
