Chapter 9
| Access Control Lists
IPv4 ACLs
– 274 –
■
32 (urg) – Urgent pointer
For example, use the code value and mask below to catch packets with the
following flags set:
■
SYN flag valid, use “control-code 2 2”
■
Both SYN and ACK valid, use “control-code 18 18”
■
SYN valid and ACK invalid, use “control-code 2 18”
Example
This example accepts any incoming packets if the source address is within subnet
10.7.1.x. For example, if the rule is matched; i.e., the rule (10.7.1.0 & 255.255.255.0)
equals the masked address (10.7.1.2 & 255.255.255.0), the packet passes through.
Console(config-ext-acl)#permit 10.7.1.1 255.255.255.0 any
Console(config-ext-acl)#
This allows TCP packets from class C addresses 192.168.1.0 to any destination
address when set for destination TCP port 80 (i.e., HTTP).
Console(config-ext-acl)#permit 192.168.1.0 255.255.255.0 any destination-port
80
Console(config-ext-acl)#
This permits all TCP packets from class C addresses 192.168.1.0 with the TCP control
code set to “SYN.”
Console(config-ext-acl)#permit tcp 192.168.1.0 255.255.255.0 any control-
flag 2 2
Console(config-ext-acl)#
Related Commands
access-list ip (270)
Time Range (128)
ip access-group
This command binds an IPv4 ACL to a port. Use the
no
form to remove the port.
Syntax
ip access-group
acl-name
in
[
time-range
time-range-name
]
no ip access-group
acl-name
in
acl-name
– Name of the ACL. (Maximum length: 32 characters)
in
– Indicates that this list applies to ingress packets.
time-range-name
- Name of the time range. (Range: 1-30 characters)
Summary of Contents for EX-3524
Page 2: ......
Page 28: ...Figures 28 ...
Page 34: ...Section I Getting Started 34 ...
Page 58: ...Chapter 1 Initial Switch Configuration Setting the System Clock 58 ...
Page 72: ...Chapter 2 Using the Command Line Interface CLI Command Groups 72 ...
Page 156: ...Chapter 5 SNMP Commands Notification Log Commands 156 ...
Page 164: ...Chapter 6 Remote Monitoring Commands 164 ...
Page 218: ...Chapter 7 Authentication Commands Management IP Filter 218 ...
Page 268: ...Chapter 8 General Security Measures Port based Traffic Segmentation 268 ...
Page 292: ...Chapter 9 Access Control Lists ACL Information 292 ...
Page 312: ...Chapter 10 Interface Commands Power Savings 312 ...
Page 324: ...Chapter 11 Link Aggregation Commands Trunk Status Display Commands 324 ...
Page 366: ...Chapter 15 Address Table Commands 366 ...
Page 428: ...Chapter 17 VLAN Commands Configuring Voice VLANs 428 ...
Page 572: ...Chapter 25 IP Interface Commands IPv6 Interface 572 ...
Page 578: ...Section I Appendices 578 ...