78CHAPTER 4: MANAGING DEVICE SECURITY
■Select from List — Selects a protocol from a list by which packets are matched to the rule.
■Protocol ID — Adds
■Source Port — Enables creating an ACL based on a specific protocol.
■Any — Enables creating an ACL based on any protocol.
■Destination Port — Defines the destination port that is matched to packets. Enabled only when TCP or UDP are selected in the Protocol list.
■Any — Enables creating an ACL Based on any protocol.
■TCP Flags — If checked, enables configuration of TCP flags matched to the packet. The possible fields are:
■Urg — Urgent pointer field significant. The urgent pointer points to the sequence number of the octet following the urgent data.
■Ack — Acknowledgement field significant. The acknowledgement field is the byte number of the next byte that the sender expects to receive from the receiver.
■Psh — Push (send) the data as soon as possible, without buffering. This is used for interactive traffic.
■Rst — Reset the connection. This invalidates the sequence numbers and aborts the session between the sender and receiver.
■Syn — Synchronize Initial Sequence Numbers (ISNs). This is used to initialize a new connection.
■Fin — Finish. This indicates there is no more data from the sender. This marks a normal closing of the session between the sender and receiver.
For each TCP flag, the possible field values are:
■Set — Enables the TCP flag.
■Unset — Disables the TCP flag.
■Don’t Care — Does not check the packet’s TCP flag.
