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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter19 Configuring Network Security with ACLs
Configuring VLAN Maps
Wiring Closet Configuration
In a wiring closet configuration, the Catalyst 3550 switch might not be running the enhanced multilayer
software image. In this configuration, the switch can still support a VLAN map and a QoS classification
ACL. In Figure 19-4, assume that HostX and Host Y are in different VLANs and are connected to wiring
closet switches A and C. Traffic from Host X to Host Y is eventually being routed by Switch B, which
is running the enhanced multilayer software image. Traffic from H ost X t o Ho st Y c a n be
access-controlled at the traffic entry point, SwitchA.
Figure19-4 Wiring Closet Configuration
If you do not want HTTP traffic switched from Host X to Host Y, you can configure a VLAN ma p on
Switch A to drop all HTTP traffic from Host X (IP address 10.1.1.32) to Host Y (IP address 10.1.1 .34 )
at Switch A and not bridge it to Switch B.
First, define the IP access list http that permits (matches) any TCP traffic on the HTTP p ort.
Switch(config)# ip access-list extended http
Switch(config-ext-nacl)# permit tcp host 10.1.1.32 host 10.1.1.34 eq www
Switch(config-ext-nacl)# exit
Next, create VLAN access map map2 so that traffic that matches the http access list is dropped and all
other IP traffic is forwarded.
Switch(config)# vlan access-map map2 10
Switch(config-access-map)# match ip address http
Switch(config-access-map)# action drop
Switch(config-access-map)# exit
Switch(config)# ip access-list extended match_all
Switch(config-ext-nacl)# permit ip any any
Switch(config-ext-nacl)# exit
Switch(config)# vlan access-map map2 20
Switch(config-access-map)# match ip address match_all
Switch(config-access-map)# action forward
Catalyst 3550 switch
with enhanced multilayer
software image
Switch A Switch C
Switch B
VLAN map: Deny HTTP
from X to Y.
HTTP is dropped
at entry point.
Host X
10.1.1.32 Host Y
10.1.1.34
VLAN 1
VLAN 2
Packet
47176
Si