Access Control Lists Flashcards
What is an Access Control List (ACL)?
An ordered list of rules that restricts or classifies network traffic
What header fields are used to match the packet to a rule? (2)
1) layer 3 IP addressing
2) layer 4 port addressing
What are the two Cisco defined ACL types
Standard and Extended
What does the Standard ACL type filter on?
Source IP address only
What does the extended ACL type filer on?
source socket address, destination socket address, and protocol
True or False: Both Standard and Extended ACL types require a wildcard mask
true
What is the syntax for the standard ACL?
access-list <number> {permit|deny} <source></source> [log]</number>
How are rules proccessed?
Top to bottom
What are end conditions for processing rules?
a match is made or all rules have been checked
What happens in no rule is matched?
the traffic is denied (called implicit deny all)
When adding a new rule where in the list does it go?
the bottom
Where should device specific rules go?
Top of the list
where to network wide / general rules go?
bottom of list
Where is a ACL installed?
A routers interface in a specific direction
what are the directions an ACL can be installed?
Ingress or egress
