Example of allowing only one IPv4 address ("host" option)

Suppose, for example, that you have configured the ACL in An ACL with an ACE that allows only one source address to filter inbound packets on VLAN 20. Because the mask is all zeros, the ACE policy dictates that a match occurs only when the source address on such packets is identical to the address configured in the ACE.

Figure 45: An ACL with an ACE that allows only one source address