Layer 2 Policy-Based Redirect

This feature allows matching packets to override the normal forwarding decision and be Layer 2 switched to the specified physical port. This is accomplished using an additional packet ACL lookup. While similar to the Layer 3 Policy-Based Redirect feature, it differs in that the packet is not modified for Layer 3 routing based on a new IP redirect next-hop. Instead, the packet uses the packet format based on the forwarding decision. When the packet is Layer 2-switched, the packet egresses the redirect port unmodified. When the packet is Layer 3-switched, the packet egresses with the Layer 3 packet modifications of the next-hop found by the normal Layer 3 forwarding lookups.

The following ACL actions are added in support of this feature:

Note

The redirect-port or redirect-port-list commands will not work for L3 switched packets matching ACL, if distributed IP ARP feature is turned ON.

You must specify the port argument in the correct format for the switch platform. On supporting switches, this argument must be in the format slot:port and this argument must be in the format port.

The port-list argument is simply a comma-separated list of port arguments. White space between port arguments is not allowed.

Here is an example of valid port-list syntax:

redirect-port-list 2:1,2:5,5:3; and redirect-port-list 3,24,5;

Here is an example of invalid port-list syntax :

redirect-port-list 2:1 2:5 5:3;
redirect-port-list 2, 4, 5;

The policy shown below redirects any TCP traffic with source Layer 4 port 81 to physical port 3:2.

entry one {
	if {
		protocol tcp;
		source-port 81;
		destination-port 200 ;
	} then {
		count num_pkts_redirected;
		redirect-port 3:2;
	}

The policy shown below redirects any in-profile traffic as defined by the meter configuration to physical port 14. The out-of-profile traffic is subject to the action specified in the meter “out-action” configuration.

entry one {
	if {
	} then {
		meter redirected_traffic;
		count num_pkts_redirected;
		redirect-port 14;
	}

The policy shown below redirects all traffic with source IP matching 192.168.1.1/24; to physical ports 2:10 and 4:7.

entry one {
if {
source-address 192.168.1.1/24;
} then {
count num_pkts_redirected;
redirect-port-list 2:10,4:7;
}

If an incorrect port format is used or if the port number specified is out of range, the following error message is displayed:

switch.5 # check policy l2pbr
Error:  Policy l2pbr has syntax errors
Line 7 : 12:3 is not a valid port.
switch.6 # check policy l2pbr
Error:  Policy l2pbr has syntax errors
Line 7 : 77 is not a valid port.

When this feature is used on ExtremeSwitching switches, the traffic egressing the redirect-port can be either tagged or untagged depending on the redirect-port VLAN configuration. The following table provides the details.