We are running a Catalyst 3525 with IOS (tm) C3500XL Software (C3500XL-C3H2S-M), Version 12.0(5.4)WC(1), MAINTENANCE INTERIM SOFTWARE However this behaves somewhat odd, and doesn't flood ports for unknown MAC addresses. After a reboot it works again. Is there a recommended IOS version that people are using? - kurtis -