3Com 2928 User Guide - Page 460

Type Filter Item Protocol Type Protocol Mask Time Range Description Select the Protocol Type option and specify the link layer protocol type by configuring the following two items: z Protocol Type: Indicates the frame type. It corresponds to the type-code field of Ethernet_II and Ethernet_SNAP frames. z Protocol Mask: Indicates the protocol mask. Select the time range during which the rule takes effect. Available time ranges are those that have been configured. Return to IPv4 ACL configuration task list. Configuration Guidelines When configuring an ACL, note that: 1) When defining rules in an ACL, you do not necessarily assign them numbers; the system can do this automatically. Refer to ACL Step. 2) You cannot create a rule with, or modify a rule to have, the same permit/deny statement as an existing rule in the ACL. 3) You can only modify the existing rules of an ACL that uses the match order of config. When modifying a rule of such an ACL, you may choose to change just some of the settings, in which case the other settings remain the same. 1-11