Administrator Guide

NOTE: When you congure ACL logging and byte counters simultaneously, byte counters may display
an incorrect value. Congure packet counters with logging instead.
Most ACL rules require one entry in the CAM. However, rules with TCP and UDP port operators (for example, gt,
lt, or range) may require more than one entry. The range of ports is congured in the CAM based on bit mask
boundaries; the space required depends on exactly what ports are included in the range.
Example
An ACL rule with a TCP port range of 4000–8000 uses eight entries in the CAM.
Rule# Data Mask From To #Covered
1 0000111110100000 1111111111100000 4000 4031 32
2 0000111111000000 1111111111000000 4032 4095 64
3 0001000000000000 1111100000000000 4096 6143 2048
4 0001100000000000 1111110000000000 6144 7167 1024
5 0001110000000000 1111111000000000 7168 7679 512
6 0001111000000000 1111111100000000 7680 7935 256
7 0001111100000000 1111111111000000 7936 7999 64
8 0001111101000000 1111111111111111 8000 8000 1
Total Ports: 4001
Example
An ACL rule with a TCP port lt 1023 uses only one entry in the CAM.
Rule# Data Mask From To #Covered
1 0000000000000000 1111110000000000 0 1023 1024
Total Ports: 1024
Related Commands
• deny — assign a lter to deny IP trac.
• deny udp — assign a lter to deny UDP trac.
deny udp
To drop user datagram protocol (UDP) packets meeting the lter criteria, congure a lter.
Syntax
deny udp {source mask | any | host ip-address} [operator port [port]]
{destination mask | any | host ip-address} [ttl operator] [dscp] [operator port
[port]] [count [byte] [order] [fragments] [monitor] [no-drop]
To remove this lter, you have two choices:
• Use the no seq sequence-number command if you know the lter’s sequence number.
•
Use the no deny udp {source mask | any | host ip-address} {destination mask |
any | host ip-address} command.
Parameters
source Enter the IP address of the network or host from which the packets were sent.
mask Enter a network mask in /prex format (/x) or A.B.C.D. The mask, when specied in
A.B.C.D format, may be either contiguous or non-contiguous.
any Enter the keyword any to specify that all routes are subject to the lter.
host ip-address Enter the keyword host then the IP address to specify a host IP address.
Access Control Lists (ACL) 207