Cisco WS-X6066-SLB-APC - Content Switching Module Software Manual page 217

Chapter 12 Configuring InterVLAN Routing
Local Proxy ARP
With Release 12.1(2)E or later releases, the Local Proxy Address Resolution Protocol (ARP) allows the
MSFC to respond to ARP requests for IP addresses within a subnet where normally no routing is
required. With local proxy ARP enabled, the MSFC responds to all ARP requests for IP addresses within
the subnet and forwards all traffic between hosts in the subnet. Use this feature only on subnets where
hosts are intentionally prevented from communicating directly by the configuration on the switch to
which they are connected.
Local proxy ARP is disabled by default. Enter the ip local-proxy-arp interface configuration command
to enable local proxy ARP on an interface. Enter the no ip local-proxy-arp interface configuration
command to disable the feature. The Internet Control Message Protocol (ICMP) redirects are disabled
on interfaces where local proxy ARP is enabled.
WCCP Layer 2 Redirection
Supervisor Engine 1 with the Policy Feature Card (PFC) supports this feature with Release 12.1(2)E
Note
or later releases. Supervisor Engine 2 with PFC2 supports this feature with Release 12.1(3a)E or later
releases.
Web Cache Communication Protocol (WCCP) Layer 2 redirection allows directly connected Cisco
Cache Engines to use Layer 2 redirection, which is more efficient than Layer 3 redirection, through
generic routing encapsulation (GRE). You can configure a directly connected Cache Engine to negotiate
use of WCCP Layer 2 redirection. WCCP Layer 2 redirection requires no configuration on the MSFC.
Enter the show ip wccp web-cache detail command to display which redirection method is in use for
each cache. Follow these guidelines when using this feature:
•
•
•
Configure the Cisco IOS WCCP as described in the Cisco IOS Configuration Fundamentals
Configuration Guide at
http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/fun_c/fcprt3/fcd305.htm
Auto State Feature
The auto state feature shuts down (or brings up) Layer 3 interfaces/subinterfaces on the MSFC and the
Multilayer Switch Module (MSM) when the following port configuration changes occur on the switch:
•
78-13315-02
WCCP Layer 2 redirection feature sets the IP flow mask to full-flow mode.
You can configure the Cisco Cache Engine software release 2.2 or later releases to use WCCP
Layer 2 redirection.
Layer 2 redirection takes place on the switch and is not visible to the MSFC. Entering the show ip
wccp web-cache detail command on the MSFC displays statistics for only the first packet of a
Layer 2 redirected flow, which provides an indication of how many flows, rather than packets, are
using Layer 2 redirection. Entering the show mls entries command on the supervisor engine
displays the other packets in the Layer 2 redirected flows.
When the last external port on a VLAN goes down, all Layer 3 interfaces/subinterfaces on that
VLAN shut down (are autostated) unless sc0 is on the VLAN or another router is in the chassis with
an interface/subinterface in the VLAN. When a Layer 3 interface goes down, this message is
reported to the console for each Layer 3 interface:
%AUTOSTATE-6-SHUT_DOWN
Catalyst 6000 Family Software Configuration Guide—Releases 6.3 and 6.4
Configuring InterVLAN Routing on the MSFC
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