Getting IP from DHCP slow / Ping slow after resuming from standby mode

Problem:

You have to wait up to ~30 seconds to obtain an IP from your DHCP server – or even if you have configured a static IP, you cannot ping a host in your network for a long time after resume from standby.

Solution:

Maybe your DHCP server does various checks (Ping, DNS, …) before he gives the IP to the client.

But in many cases, a network switch setting is the problem: STP (Spanning Tree Protocol). Disable it, or leave it enabled but set the Port Fast mode for all ports.