3Com 3CBLSG48 User Guide - Page 80

CHAPTER 4: MANAGING DEVICE SECURITY 69 ■ Destination IP Address - If selected, enables matching the destination port IP address to which packets are addressed to the ACE, according to a wildcard mask. The field value is either user defined or Any. If Any is selected, accepts any destination IP address and disables wildcard mask filtering. Wild Card Mask - Indicates the destination IP Address wildcard mask. Wildcards are used to mask all or part of a destination IP Address. Wildcard masks specify which bits are used and which bits are ignored. A wildcard mask of 255.255.255.255 indicates that no bit is important. A wildcard mask of 0.0.0.0 indicates that all bits are important. For example, if the destination IP address 149.36.184.198 and the wildcard mask is 0.0.0.255, the first three bytes of the IP address are matched, while the last eight bits are ignored. For the destination IP address 149.36.184.198, this wildcard mask matches all IP addresses in the range 149.36.184.0 to 149.36.184.255. A wildcard mask must not contain leading zeroes. For example, a wildcard mask of 056.022.075.032 is invalid, but a wildcard mask of 56.22.75.32 is valid.