CSX200 Configuration with QuickSETCSX200 Family User’s Guide 67The following definitions explain the fields in the Firewall configuration window.ACL (Access Control List) — The Access Control List number is a number assigned to aspecific list of sequence numbers.Sequence — A number assigned to individual access filters in an access list. As only one IPAccess Control List can be applied to each port, a single list often includes several access controlfilters. Each filter permits or denies access to or from a certain host, subnet, or network. When anaccess control list contains multiple filters, the filters are referenced in order of their sequencenumbers.Source IP — The Source IP field displays the IP address of the source device accorded thepermissions set in the permissions field. To set permissions for a source device, place the cursor inthe Source IP field and type the IP address of the source that you wish to set permissions.Source Mask — Displays the mask for the Source IP address specified in the Source IP field. Toset the mask for the specified source IP address, place the cursor in the Source Mask field and typethe mask.The default Mask for both the source and destination addresses is 0.0.0.0, which masks the entireaddress, causing all addresses to match the filter. In other words, the default access control listallows all traffic to pass. Entering a mask of 255.255.255.255 causes only packets matching theexact address you have entered to match the filter.For a Class C address, entering a mask of 255.255.255.0 causes packets with the same Class Csubnet as the IP address to match, thereby causing the access control filter to apply to all hosts onthis particular subnet.Dest IP — The Dest IP field displays the IP address of the destination device accorded thepermissions set in the permissions field. To set permissions for a certain destination device, placethe cursor in the Dest IP field and type the IP address of the destination for which you wish to setpermissions.Dest Mask — Displays the mask for the Destination IP address specified in the Dest IP field. Toset the mask for the specified destination IP address, place the cursor in the Dest Mask field andtype the mask.NOTEThe Add Firewall button clears the fields in the Firewall configuration window,allowing you to type in the fields as necessary. The Apply Changes button adds thenewly entered filter to the Access Control List.
