Process ACLs access-list cisco

Traffic that comes into the router is compared to ACL entries based on the adjustment that the entries action in the router. New statements are added to the end of the list. The router continues to attending until it has a match. If no matches are begin back the router alcove the end of the list, the cartage is denied. For this reason, you should accept the frequently hit entries at the top of the list. There is an adumbrated abjure for cartage that is not permitted. A single-entry ACL with alone one abjure access has the aftereffect of abstinent all traffic. You charge accept at atomic one admittance account in an ACL or all cartage is blocked. These two ACLs (101 and 102) accept the aforementioned effect.

access-list 101 admittance ip 10.1.1.0 0.0.0.255 172.16.1.0 0.0.0.255

access-list 102 admittance ip 10.1.1.0 0.0.0.255 172.16.1.0 0.0.0.255

access-list 102 abjure ip any any

In this example, the aftermost access is sufficient. You do not charge the aboriginal three entries because TCP includes Telnet, and IP includes TCP, User Datagram Protocol (UDP), and Internet Control Message Protocol (ICMP).

access-list 101 admittance tcp host 10.1.1.2 host 172.16.1.1 eq telnet

access-list 101 admittance tcp host 10.1.1.2 host 172.16.1.1

access-list 101 admittance udp host 10.1.1.2 host 172.16.1.1

access-list 101 admittance ip 10.1.1.0 0.0.0.255 172.16.1.0 0.0.0.255