Cisco 500 Series Quick Start Manual page 17

No IP route:
If the switch and your computer are in different IP subnets, you need
one or more routers to route the packets between the two subnets.
Unusually long access time:
Most connections will be available in a few seconds. Due to the
standard spanning tree loop detection logic, adding new connections
might take 30 to 60 seconds for the affected interfaces and/or LAN to
become operational.
500 Series Stackable Managed Switches 17