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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 19 Configuring Network Security with ACLs
Configuring VLAN Maps
This is a an example of a log for an extended ACL:
01:24:23:%SEC-6-IPACCESSLOGDP:list ext1 permitted icmp 10.1.1.15 -> 10.1.1.61 (0/0), 1
packet
01:25:14:%SEC-6-IPACCESSLOGDP:list ext1 permitted icmp 10.1.1.15 -> 10.1.1.61 (0/0), 7
packets
01:26:12:%SEC-6-IPACCESSLOGP:list ext1 denied udp 0.0.0.0(0) -> 255.255.255.255(0), 1
packet
01:31:33:%SEC-6-IPACCESSLOGP:list ext1 denied udp 0.0.0.0(0) -> 255.255.255.255(0), 8
packets
Note that all logging entries for IP ACLs start with
%SEC-6-IPACCESSLOG
with minor variations in format
depending on the kind of ACL and the access entry that has been matched.
This is an example of an output message when the log-input keyword is entered:
00:04:21:%SEC-6-IPACCESSLOGDP:list inputlog permitted icmp 10.1.1.10 (Vlan1
0001.42ef.a400) -> 10.1.1.61 (0/0), 1 packet
A log message for the same sort of packet using the log keyword does not include the input interface
information:
00:05:47:%SEC-6-IPACCESSLOGDP:list inputlog permitted icmp 10.1.1.10 -> 10.1.1.61 (0/0), 1
packet
Configuring VLAN Maps
This section describes how to configure VLAN maps, which is the only way to control filtering within
a VLAN. VLAN maps have no direction. To filter traffic in a specific direction by using a VLAN map,
you need to include an ACL with specific source or destination addresses. If there is a match clause for
that type of packet (IP or MAC) in the VLAN map, the default action is to drop the packet if the packet
does not match any of the entries within the map. If there is no match clause for that type of packet, the
default is to forward the packet.
Note
For complete syntax and usage information for the commands used in this section, refer to the
Catalyst 3550 Multilayer Switch Command Reference for this release.
To create a VLAN map and apply it to one or more VLANs, perform these steps:
Step 1
Create the standard or extended IP ACLs or named MAC extended ACLs that you want to apply to the
VLAN. See the
“Creating Standard and Extended IP ACLs” section on page 19-6
and the
“Creating
Named MAC Extended ACLs” section on page 19-28
.
Step 2
Enter the vlan access-map global configuration command to create a VLAN ACL map entry.
Step 3
In access map configuration mode, optionally enter an action—forward (the default) or drop—and
enter the match command to specify an IP packet or a non-IP packet (with only a known MAC address)
and to match the packet against one or more ACLs (standard or extended).
Note
If the VLAN map has a match clause for the type of packet (IP or MAC) and the packet does
not match the type, the default is to drop the packet. If there is no match clause in the VLAN
map for that type of packet, and no action specified, the packet is forwarded.
