Chapter 5: Quality of Service
Table 13:
| TCP/UDP |
| TCP/UDP |
| TCP/UDP |
Number | Application | Number | Application | Number | Application |
|
|
|
|
|
|
20 | 79 | finger | 179 | bgp | |
21 | ftp | 80 | http | 194 | irc |
22 | ssh | 109 | pop2 | 220 | imap3 |
23 | telnet | 110 | pop3 | 389 | ldap |
25 | smtp | 111 | sunrpc | 443 | https |
37 | time | 119 | nntp | 520 | rip |
42 | name | 123 | ntp | 554 | rtsp |
43 | whois | 143 | imap | 1645, 1812 | RADIUS |
53 | domain | 144 | news | 1813 | RADIUS accounting |
69 | tftp | 161 | snmp | 1985 | hsrp |
70 | gopher | 162 | snmptrap |
|
|
|
|
|
|
|
|
Understanding ACL Priority
Each ACL has a unique priority value, based on its number. The lower the ACL number, the higher the priority, so ACL 1 has the highest priority.
The priority value is used to decide which ACL rule to apply when a packet matches one or more ACLs. When an incoming packet matches the highest priority ACL, the ACL’s configured action takes place. The other assigned ACLs are considered in numeric order, from lowest to highest.
In the following example, the switch considers ACL 128 before ACL 130 because ACL 128 has a higher priority. The order in which the ACLs are assigned to a port does not affect their priority.
Port 1 access group
ACL IP Extended 128:
TCP
Port number = 80
Action = permit
ACL IP Extended 129:
TCP
Port number = 23
Action = deny
ACL IP Extended 130:
TCP
Port number = less than 100
Action = permit
Using ACL Filters 55