Dell S3048-ON, Configuration Manual

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Counting ACL Hits
You can view the number of packets matching the ACL by using the
count
option when creating ACL entries.
1 Create an ACL that uses rules with the count option. Refer to Configure a Standard IP ACL Filter .
2 Apply the ACL as an inbound or outbound ACL on an interface.
3
show ip accounting access-list
EXEC Privilege mode
View the number of packets matching the ACL.
Configure Ingress ACLs
Ingress ACLs are applied to interfaces and to traffic entering the system.
These system-wide ACLs eliminate the need to apply ACLs onto each interface and achieves the same results. By localizing target traffic, it
is a simpler implementation.
To create an ingress ACL, use the
ip access-group
command in EXEC Privilege mode. The example shows applying the ACL, rules to
the newly created access group, and viewing the access list.
Example of Applying ACL Rules to Ingress Traffic and Viewing ACL Configuration
To specify ingress, use the
in
keyword. Begin applying rules to the ACL with the
ip access-list extended abcd
command. To
view the access-list, use the
show
command.
Dell(conf)#interface gigabitethernet 1/1
Dell(conf-if-gi1/1)# ip access-group abcd in
Dell(conf-if-gi1/1)#show config
!
gigabitethernet 1/1
no ip address
ip access-group abcd in
no shutdown
Dell(conf-if-gi1/1)#end
Dell#configure terminal
Dell(conf)# ip access-list extended abcd
Dell(config-ext-nacl)#permit tcp any any
Dell(config-ext-nacl)#deny icmp any any
Dell(config-ext-nacl)#permit 1.1.1.2
Dell(config-ext-nacl)#end
Dell# show ip accounting access-list
!
Extended Ingress IP access list abcd on gigabitethernet 1/1
seq 5 permit tcp any any
seq 10 deny icmp any any
seq 15 permit 1.1.1.2
Configure Egress ACLs
Egress ACLs are applied to line cards and affect the traffic leaving the system. Configuring egress ACLs onto physical interfaces protects
the system infrastructure from attack — malicious and incidental — by explicitly allowing only authorized traffic. These system-wide ACLs
eliminate the need to apply ACLs onto each interface and achieves the same results. By localizing target traffic, it is a simpler
implementation.
To restrict egress traffic, use an egress ACL. For example, when a denial of service (DOS) attack traffic is isolated to a specific interface,
you can apply an egress ACL to block the flow from the exiting the box, thus protecting downstream devices.
124 Access Control Lists (ACLs)