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Configuring Network Security with ACLs
Configuration Examples for Network Security with ACLs
For an entry in a named IP ACL, use the
remark
access-list configuration command. To remove the remark, use the
no
form of this command.
In this example, the Jones subnet is not allowed to use outbound Telnet:
Switch(config)#
ip access-list extended telnetting
Switch(config-ext-nacl)#
remark Do not allow Jones subnet to telnet out
Switch(config-ext-nacl)#
deny tcp host 171.69.2.88 any eq telnet
Applying ACL to a Port: Example
This example shows how to apply access list 2 to a port to filter packets entering the port:
Switch(config)#
interface GigabitEthernet1/17
Switch(config-if)#
ip access-group 2 in
Applying an ACL to an Interface: Example
For example, if you apply this ACL to an interface:
permit tcp
source source-wildcard
destination destination-wildcard
range 5 60
permit tcp
source source-wildcard
destination destination-wildcard
range 15 160
permit tcp
source source-wildcard
destination destination-wildcard
range 115 1660
permit tcp
source source-wildcard
destination destination-wildcard
And if this message appears:
ACLMGR-2-NOVMR: Cannot generate hardware representation of access list [chars]
The flag-related operators are not available. To avoid this issue,
Move the fourth ACE before the first ACE by using
ip access-list resequence
global configuration command:
permit tcp
source source-wildcard
destination destination-wildcard
permit tcp
source source-wildcard
destination destination-wildcard
range 5 60
permit tcp
source source-wildcard
destination destination-wildcard
range 15 160
permit tcp
source source-wildcard
destination destination-wildcard
range 115 1660
or
Rename the ACL with a name or number that alphanumerically precedes the other ACLs (for example, rename ACL
79
to ACL
1
).
You can now apply the first ACE in the ACL to the interface. The switch allocates the ACE to available mapping bits in
the Opselect index and then allocates flag-related operators to use the same bits in the TCAM.
Router ACLs function as follows:
The hardware controls permit and deny actions of standard and extended ACLs (input and output) for security
access control.
If
log
has not been specified, the flows that match a
deny
statement in a security ACL are dropped by the hardware
if
ip unreachables
is disabled. The flows matching a
permit
statement are switched in hardware.
Adding the
log
keyword to an ACE in a router ACL causes a copy of the packet to be sent to the CPU for logging
only. If the ACE is a
permit
statement, the packet is still switched and routed in hardware.
Содержание IE 4000
Страница 12: ...8 Configuration Overview Default Settings After Initial Switch Configuration ...
Страница 52: ...48 Configuring Interfaces Monitoring and Maintaining the Interfaces ...
Страница 108: ...104 Configuring Switch Clusters Additional References ...
Страница 128: ...124 Performing Switch Administration Additional References ...
Страница 130: ...126 Configuring PTP ...
Страница 140: ...136 Configuring CIP Additional References ...
Страница 146: ...142 Configuring SDM Templates Configuration Examples for Configuring SDM Templates ...
Страница 192: ...188 Configuring Switch Based Authentication Additional References ...
Страница 244: ...240 Configuring IEEE 802 1x Port Based Authentication Additional References ...
Страница 274: ...270 Configuring SGT Exchange Protocol over TCP SXP and Layer 3 Transport Configuring Cisco TrustSec Caching ...
Страница 298: ...294 Configuring VLANs Additional References ...
Страница 336: ...332 Configuring STP Additional References ...
Страница 408: ...404 Configuring DHCP Additional References ...
Страница 450: ...446 Configuring IGMP Snooping and MVR Additional References ...
Страница 490: ...486 Configuring SPAN and RSPAN Additional References ...
Страница 502: ...498 Configuring Layer 2 NAT ...
Страница 559: ...555 Configuring Network Security with ACLs How to Configure Network Security with ACLs Creating a Numbered Extended ACL ...
Страница 770: ...766 Configuring IPv6 MLD Snooping Related Documents ...
Страница 930: ...926 Configuring IP Unicast Routing Related Documents ...
Страница 956: ...952 Configuring IPv6 Unicast Routing Configuring IPv6 network 2010 AB8 2 48 network 2010 AB8 3 48 exit address family ...
Страница 976: ...972 Configuring Cisco IOS IP SLAs Operations Additional References ...
Страница 978: ...974 Dying Gasp ...
Страница 990: ...986 Configuring Enhanced Object Tracking Monitoring Enhanced Object Tracking ...
Страница 994: ...990 Configuring MODBUS TCP Displaying MODBUS TCP Information ...
Страница 996: ...992 Ethernet CFM ...
Страница 1030: ...1026 Working with the Cisco IOS File System Configuration Files and Software Images Working with Software Images ...
Страница 1066: ...1062 Using an SD Card SD Card Alarms ...