ip option

Blocks packets that have IP options. Also blocks packets that are marked for processing directly by the device's control plane processing unit.

Syntax

ip option [ disable | disable-cpu ]

no ip option [ disable | disable-cpu ]

show running-configuration ip

Command Default

By default, packets with IP options are not blocked. Similarly, packets that are marked directly for the Control Plane Processing Unit (CPU) are not blocked by default.

Modes

Global configuration mode

Usage Guidelines

The disable and disable-cpu options are mutually exclusive. You cannot use one if the other is already configured. For example, if you have configured the disable option, you cannot configure the disable-cpu option without removing the previous configuration.

Use the no form of the command to unblock packets that have IP options.

The show running-configuration ip checks if ip option disable is already configured or not.

Examples

The following example blocks packets that have IP options set.

SLX#configure terminal
SLX (config) # ip option disable

The following example blocks packets that are destined for the CPU.

SLX# configure terminal
SLX (config) # ip option disable-cpu

The following example displays the error that will be displayed when you try to configure over an existing ip option configuration.

SLX# configure terminal
SLX (config) # ip option ?
Possible completions:
  disable      IP option disable
  disable-cpu  IP option disable for CPU

SLX (config)# ip option disable-cpu
SLX (config)# do show running-config ip option

The following example displays an error when the other command is executed.

ip option disable-cpu

SLX (config)# ip option disable
    %% Error: IP option disable-cpu is configured.     
    It needs to be unconfigured before executing this command.