enable icmp redirects

enable icmp redirects {ipv4} {vlan all | {vlan} {name}}


Enables the generation of ICMP redirect messages on one or all VLANs.

Syntax Description

name Specifies a VLAN name.



Usage Guidelines

This option only applies to the switch when the switch is in routing mode.

ICMP redirects are used in the situation where there are multiple routers in the same subnet. If a host sends a packet to one gateway, the gateway router looks at its route table to find the best route to the destination. If it sees that the best route is through a router in the same subnet as the originating host, the switch sends an ICMP redirect (type 5) message to the host that originated the packet, telling it to use the other router with the better route. The switch also forwards the packet to the destination.

ICMP redirects are only generated for IPv4 unicast packets that are "slowpath" forwarded by the CPU. That is, IPv4 packets that contain IP Options, or packets whose Destination IP is not in the Layer 3 forwarding hardware table.


The following example enables the generation of ICMP redirect messages on all VLANs:

enable icmp redirects


This command was first available in ExtremeXOS 10.1.

Platform Availability

This command is available on ExtremeSwitching 5320, 5420, 5520, and 5720 series switches.