Chapter 34 Configuring Network Security with ACLs

Using VLAN Maps with Router ACLs

Examples of Router ACLs and VLAN Maps Applied to VLANs

This section gives examples of applying router ACLs and VLAN maps to a VLAN for switched, bridged, routed, and multicast packets. Although the following illustrations show packets being forwarded to their destination, each time the packet’s path crosses a line indicating a VLAN map or an ACL, it is also possible that the packet might be dropped, rather than forwarded.

ACLs and Switched Packets

Figure 34-6shows how an ACL is applied on packets that are switched within a VLAN. Packets switched within the VLAN without being routed or forwarded by fallback bridging are only subject to the VLAN map of the input VLAN.

Figure 34-6 Applying ACLs on Switched Packets

 

Input

Output

 

VLAN 10

router

router

VLAN 20

map

ACL

ACL

map

Frame

 

 

 

Host A

 

 

 

(VLAN 10)

Routing function or

 

 

 

 

fallback bridge

 

Host C (VLAN 10)

VLAN 10

 

Packet

VLAN 20

 

 

 

101357

ACLs and Bridged Packets

Figure 34-7shows how an ACL is applied on fallback-bridged packets. For bridged packets, only Layer 2 ACLs are applied to the input VLAN. Only non-IP, non-ARP packets can be fallback-bridged.

 

Catalyst 3750-E and 3560-E Switch Software Configuration Guide

34-38

OL-9775-02

Page 736
Image 736
Cisco Systems 3750E manual Examples of Router ACLs and Vlan Maps Applied to VLANs, ACLs and Switched Packets, 34-38