Cisco Cisco Packet Data Interworking Function (PDIF) Guia De Resolução De Problemas
Access Control Lists
Understanding ACLs ▀
Cisco ASR 5000 Series Enhanced Feature Configuration Guide ▄
OL-22982-01
TCP: The rule applies to any Transport Control Protocol (TCP) traffic and could be filtered on any combination
of source/destination IP addresses, a specific port number, or a group of port numbers.
Important:
TCP port numbers definitions can be found at www.iana.org.
UDP: The rule applies to any User Datagram Protocol (UDP) traffic and could be filtered on any combination of
source/destination IP addresses, a specific port number, or a group of port numbers.
Important:
UDP port numbers definitions can be found at www.iana.org.
Rule Order
A single ACL can consist of multiple rules. Each packet is compared against each of the ACL rules, in the order in
which they were entered, until a match is found. Once a match is identified, all subsequent rules are ignored.
which they were entered, until a match is found. Once a match is identified, all subsequent rules are ignored.
Additional rules can be added to an existing ACL and properly ordered using either of the following options:
Before
After
Using these placement options requires the specification of an existing rule in the ACL and the configuration of the new
rule as demonstrated by the following flow:
rule as demonstrated by the following flow: