Applying Egress Layer 3 ACLs (Control-Plane)
By default, packets originated from the system are not filtered by egress ACLs.
For example, if you initiate a ping session from the system and apply an egress ACL to block this type of
traffic on the interface, the ACL does not affect that ping traffic. The Control Plane Egress Layer 3 ACL
feature enhances IP reachability debugging by implementing control-plane ACLs for CPU-generated and
CPU-forwarded traffic. Using permit rules with the
count
option, you can track on a per-flow basis
whether CPU-generated and CPU-forwarded packets were transmitted successfully.
1.
Apply Egress ACLs to IPv4 system traffic.
CONFIGURATION mode
ip control-plane [egress filter]
2.
Apply Egress ACLs to IPv6 system traffic.
CONFIGURATION mode
ipv6 control-plane [egress filter]
3.
Create a Layer 3 ACL using permit rules with the
count
option to describe the desired CPU traffic.
CONFIG-NACL mode
permit ip {
source mask
| any | host
ip-address
} {
destination mask
| any |
host
ip-address
} count
FTOS Behavior
: Virtual router redundancy protocol (VRRP) hellos and internet group management
protocol (IGMP) packets are not affected when you enable egress ACL filtering for CPU traffic. Packets
sent by the CPU with the source address as the VRRP virtual IP address have the interface MAC address
instead of VRRP virtual MAC address.
IP Prefix Lists
IP prefix lists control routing policy. An IP prefix list is a series of sequential filters that contain a matching
criterion (examine IP route prefix) and an action (permit or deny) to process routes. The filters are
processed in sequence so that if a route prefix does not match the criterion in the first filter, the second
filter (if configured) is applied. When the route prefix matches a filter, Dell Networking OS drops or
forwards the packet based on the filter’s designated action. If the route prefix does not match any of the
filters in the prefix list, the route is dropped (that is, implicit deny).
A route prefix is an IP address pattern that matches on bits within the IP address. The format of a route
prefix is A.B.C.D/X where A.B.C.D is a dotted-decimal address and /X is the number of bits that should be
matched of the dotted decimal address. For example, in 112.24.0.0/16, the first 16 bits of the address
112.24.0.0 match all addresses between 112.24.0.0 to 112.24.255.255.
The following examples show permit or deny filters for specific routes using the
le
and
ge
parameters,
where x.x.x.x/x represents a route prefix:
• To deny only /8 prefixes, enter
deny x.x.x.x/x ge 8 le 8
.
• To permit routes with the mask greater than /8 but less than /12, enter
permit x.x.x.x/x ge 8
.
• To deny routes with a mask less than /24, enter
deny x.x.x.x/x le 24
.
• To permit routes with a mask greater than /20, enter
permit x.x.x.x/x ge 20
.
The following rules apply to prefix lists:
116
Access Control Lists (ACLs)
Summary of Contents for S6000-ON
Page 1: ...Dell Configuration Guide for the S6000 ON System 9 9 0 0 ...
Page 557: ...Figure 80 Configuring OSPF and BGP for MSDP Multicast Source Discovery Protocol MSDP 557 ...
Page 562: ...Figure 83 MSDP Default Peer Scenario 1 562 Multicast Source Discovery Protocol MSDP ...
Page 563: ...Figure 84 MSDP Default Peer Scenario 2 Multicast Source Discovery Protocol MSDP 563 ...
Page 564: ...Figure 85 MSDP Default Peer Scenario 3 564 Multicast Source Discovery Protocol MSDP ...
Page 665: ...Policy based Routing PBR 665 ...
Page 818: ...Figure 110 Single and Double Tag TPID Match 818 Service Provider Bridging ...
Page 819: ...Figure 111 Single and Double Tag First byte TPID Match Service Provider Bridging 819 ...
Page 995: ...Figure 140 Setup OSPF and Static Routes Virtual Routing and Forwarding VRF 995 ...
