Concept Guide
seq 10 deny icmp any any
seq 15 permit 1.1.1.2
Congure Egress ACLs
Egress ACLs are applied to line cards and aect the trac leaving the system. Conguring egress ACLs onto physical interfaces protects
the system infrastructure from attack — malicious and incidental — by explicitly allowing only authorized trac. These system-wide ACLs
eliminate the need to apply ACLs onto each interface and achieves the same results. By localizing target trac, it is a simpler
implementation.
To restrict egress trac, use an egress ACL. For example, when a denial of service (DOS) attack trac is isolated to a specic interface,
you can apply an egress ACL to block the ow from the exiting the box, thus protecting downstream devices.
To create an egress ACL, use the ip access-group command in EXEC Privilege mode. The example shows viewing the conguration,
applying rules to the newly created access group, and viewing the access list.
NOTE: VRF based ACL congurations are not supported on the egress trac.
Example of Applying ACL Rules to Egress Trac and Viewing ACL Conguration
To specify ingress, use the out keyword. Begin applying rules to the ACL with the ip access-list extended abcd command. To
view the access-list, use the show command.
DellEMC(conf)#interface GigabitEthernet 1/1
DellEMC(conf-if-gi-1/1)#ip access-group abcd out
DellEMC(conf-if-gi-1/1)#show config
!
GigabitEthernet 1/1
no ip address
ip access-group abcd out
no shutdown
DellEMC(conf-if-gi-1/1)#end
DellEMC#configure terminal
DellEMC(conf)#
ip access-list extended abcd
DellEMC(config-ext-nacl)#permit tcp any any
DellEMC(config-ext-nacl)#deny icmp any any
DellEMC(config-ext-nacl)#permit 1.1.1.2
DellEMC(config-ext-nacl)#end
DellEMC#
show ip accounting access-list
!
Extended Ingress IP access list abcd on gigabitethernet 0/0
seq 5 permit tcp any any
seq 10 deny icmp any any
seq 15 permit 1.1.1.2
DellEMC#configure terminal
DellEMC(conf)#interface gigabitethernet 1/2
DellEMC(conf-if-gi-1/2)#ip vrf forwarding blue
DellEMC(conf-if-gi-1/2)#show config
!
interface GigabitEthernet 1/2
ip vrf forwarding blue
no ip address
shutdown
DellEMC(conf-if-gi-1/2)#
DellEMC(conf-if-gi-1/2)#
DellEMC(conf-if-gi-1/2)#end
DellEMC#
126
Access Control Lists (ACLs)