These are used to control what traffic flows into and out of your subnet. The Inbound Rules and Outbound Rules tabs are comprised of six fields:
Let's go over these fields one by one:
- Rule #: The rule numbers are used to ascertain the order in which the rules are read. When your NACL processes traffic, the rules will be read in ascending order until a rule match is found. With this in mind, it's a best practice to leave number gaps within your rules to allow you to add more in over time without having to move everything around.
- Type: Here, you can select a number of common protocol types, such as LDAP, HTTP, DNS, and so on. You can alternatively specify custom TCP/UDP/ICMP protocols as well.
- Protocol: Depending on your selection in the previous Type field, you might be able to select a specific protocol (number).
- Port Range: Here, you can enter the port range for any custom protocol entries that you selected.
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