Configuring Switching Methods on a Catalyst 1900 or 2820

Recall from Chapter 3 that Cisco switches support three major switching methods – FragmentFree, Cut-Through, and Store-and-Forward. The Catalyst 1900 series supports only two of these methods, FragmentFree and Store-and-Forward. FragmentFree is the method configured by default.

To view the current switching method enabled on a switch, use the show port system command. To change the switching method, use the switching-mode command followed by either fragment-free or store-and-forward. In the example below, I have changed the switching method to Store-and-Forward.

Cisco1912#show port system
Switching mode: FragmentFree
Use of store and forward for multicast: Disabled
Network port: None
Half duplex backpressure (10 Mbps ports): Disabled
Enhanced Congestion Control (10 Mbps ports): Disabled
Default port LED display mode: Port Status
Cisco1912#config t
Enter configuration commands, one per line. End with CNTL/Z
Cisco1912(config)#switching-mode store-and-forward

Author: Dan DiNicolo

Dan DiNicolo is a freelance author, consultant, trainer, and the managing editor of He is the author of the CCNA Study Guide found on this site, as well as many books including the PC Magazine titles Windows XP Security Solutions and Windows Vista Security Solutions. Click here to contact Dan.