Configuring Egress Acls; Egress Layer 3 Acl Lookup For Control-Plane Ip Traffic - Dell Force10 MXL Blade Configuration Manual

Configuring Egress ACLs

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.
Use an egress ACL when you would like to restrict egress traffic. For example, when a DOS attack traffic
is isolated to one particular interface, you can apply an egress ACL to block that particular flow from
exiting the box, thereby protecting downstream devices.
To create an egress ACLs, use the
example also shows viewing the configuration, applying rules to the newly created access group, and
viewing the access list.
Figure 5-14. Creating an Egress ACL
FTOS(conf)#interface tengig 0/0
FTOS(conf-if-tengig0/0)#ip access-group abcd
FTOS(conf-if-tengig0/0)#show config
!
tengigethernet 0/0
no ip address
ip access-group abcd out
no shutdown
FTOS(conf-if-tengig0/0)#end
FTOS#configure terminal
FTOS(conf)#ip access-list extended
FTOS(conf-ext-nacl)#permit tcp any any
FTOS(conf-ext-nacl)#deny icmp any any
FTOS(conf-ext-nacl)#permit 1.1.1.2
FTOS(conf-ext-nacl)#end
FTOS#show ip accounting access-list
!
Extended Ingress IP access list abcd on tengigethernet 0/0
seq 5 permit tcp any any
seq 10 deny icmp any any
seq 15 permit 1.1.1.2

Egress Layer 3 ACL Lookup for Control-Plane IP Traffic

By default, packets originated from the system are not filtered by egress ACLs. If you initiate a ping
session from the system, for example, and apply an egress ACL to block this type of traffic on the
interface, the ACL does not affect that ping traffic.
84
| Access Control Lists (ACLs)
command in EXEC Privilege mode
ip access-group
out
abcd
(Figure
Use the "out" keyword
to specify egress.
Begin applying rules to
the ACL named
"abcd."
View the access-list.
5-14). This