Handbook

N8406-023 1Gb Intelligent L3 Switch Application Guide 75
Table 15 Well-known application ports
Number
TCP/UDP
Application
Number
TCP/UDP
Application
Number
TCP/UDP
Application
70
gopher
162
snmptrap
Table 16 Well-krown TCP flag values
Flag
Value
URG
0x0020
ACK
0x0010
PSH
0x0008
RST
0x0004
SYN
0x0002
FIN
0x0001
Packet Format
Ethernet format (EthernetⅡ, SNAP, LLC)
Ethernet tagging format
Egress port packets
Note that the egress port ACL will not match a broadcast, multicast, unknown unicast, or Layer 3 packet. The
egress port ACL will not match packets if the destination port is a trunk member.
Summary of ACL actions
Actions determine how the traffic is treated. The switch QoS actions include the following:
Pass or Drop
Re-mark a new DiffServ Code Point (DSCP)
Re-mark the 802.1p field
Set the COS queue
Understanding ACL precedence
Each ACL has a unique precedence level, based on its number. When an incoming packet matches the highest
precedence ACL, the ACL‘s configured action takes place. The other assigned ACLs also are considered, in order
of precedence.
ACLs are divided into Precedence Groups, as shown in the following table. Each Precedence Group provides a
different set of packet classifiers for the ACLs within the Precedence Group.
Table 17 ACL Precedence Groups
Precedence Group
ACLs
Packet Classifiers
Precedence Level
Precedence Group 1
ACL 1 – ACL 127
Source MAC address
Destination MAC address
Ethernet Type
VLAN ID
802.1p
Packet Format
Low
Precedence Group 2
ACL 128 – ACL 254
Source MAC address
Destination MAC address
Ethernet type
VLAN ID
802.1p
Packet format