Traffic/Security Filters and Monitors

Filter Types and Operation

Source-Port Filters

This filter type enables the switch to forward or drop traffic from all end nodes on the indicated source-port to specific destination ports.

 

End

 

 

 

 

 

 

 

 

 

 

 

 

Node

 

 

 

 

 

 

 

 

 

 

Server

 

“A”

 

 

 

Port

 

 

 

Port

 

 

Hub

 

Switch 6120

 

 

 

 

 

 

 

End

 

 

 

1

 

 

Configured for

 

 

2

 

 

Node

 

 

 

 

 

 

Source-Port

 

 

 

 

 

“B”

 

 

 

 

 

 

Filtering

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

End

 

 

 

 

 

 

 

 

 

 

 

 

Node

 

 

 

 

 

 

 

 

 

 

 

“C”

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Configuring a source-port filter to drop traffic received on port 1 with an outbound destination of port 2 means that End Nodes A, B, and C cannot send traffic to the server. To block traffic in the opposite direction, you would also configure a source-port filter to drop traffic received on port 2 with an outbound destination of port 1.

Figure 9-1. Example of a Source-Port Filter Application

Operating Rules for Source-Port Filters

You can configure one source-port filter for each physical port and port trunk on the switch. (Refer to the filter command on page 9-16.)

You can include all destination ports and trunks in the switch on a single source-port filter.

Each source-port filter includes:

One source port or port trunk (trk1, trk2, ...trkn)

A set of destination ports and/or port trunks that includes all untrunked LAN ports and port trunks on the switch

An action (forward or drop) for each destination port or port trunk

When you create a source-port filter, the switch automatically sets the filter to forward traffic from the designated source to all destinations for which you do not specifically configure a “drop” action. Thus, it is not necessary to configure a source-port filter for traffic you want the switch to forward unless the filter was previously configured to drop the desired traffic.

9-4