8.4 One of the non payload options in Snort is flow. This option distinguishes between clients and servers. This option can be used to specify a match only for packets flowing in one direction (client to server or vice versa) and can specify a match only on established TCP connections. Consider the following Snort rule:

a. What does this rule do?

b. Comment on the significance of this rule if the Snort devices is placed inside or outside of the external firewall.