36-2
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
OL-8978-04
Chapter 36 Configuring Layer 3 Protocol Filtering
Default Layer 3 Protocol Filtering Configuration
For example, if a host that supports both IP and Internetwork Packet Exchange (IPX) is connected to a
switch port that is configured as
auto
for IPX, but the host is transmitting only the IP traffic, the port to
which the host is connected does not forward any IPX flood traffic to the host. However, if the host sends
an IPX packet, the supervisor engine software detects the protocol traffic and the port is added to the
IPX group, allowing the port to receive the IPX flood traffic. If the host stops sending the IPX traffic for
more than 60 minutes, the port is removed from the IPX protocol group.
By default, the ports are configured to
on
for the IP protocol group. Typically, you should configure a
port to
auto
for IP only if there is a directly connected end station out the port. The default port
configuration for IPX and Group is
auto
.
With Layer 3 protocol filtering enabled, the ports are identified on a protocol basis. A port can be a
member of one or more protocol groups. The flood traffic for each protocol group is forwarded out a port
only if that port belongs to the appropriate protocol group.
The packets are classified into these protocol groups:
•
IP
•
IPX
•
AppleTalk, DECnet, and Banyan VINES (
group
mode)
•
Packets not belonging to any of these protocols
Default Layer 3 Protocol Filtering Configuration
Table 36-1
shows the default Layer 3 protocol filtering configuration.
Configuring Layer 3 Protocol Filtering on the Switch
These sections describe how to configure Layer 3 protocol filtering on the Ethernet-type VLANs and on
any type of Ethernet port:
•
Enabling Layer 3 Protocol Filtering, page 36-3
•
Disabling Layer 3 Protocol Filtering, page 36-3
Table 36-1
Layer 3 Protocol Filtering Default Configuration
Feature
Default Value
Layer 3 protocol filtering
Disabled
ip
mode
on
ipx
mode
auto
group
mode
auto
