Enables the TCP SYN cookies defense mechanism against SYN attacks. Use no tcp syn-cookies to disable the TCP SYN cookies defense mechanism against SYN attacks.
Prolog information
Metadata
Keywords:
Note:
SYN cookies are disabled by default.
When enabling or disabling SYN cookies, you are prompted to copy the running configuration to the start-up configuration using the copy running-config startup-config command, and then to reset the device.
This command applies to IPv4 only.
Syntax
[no] tcp syn-cookies
User level
read-write
Context
general
Examples
To enable SYN cookies:
Gxxx-001(config)# tcp syn-cookies To enable tcp syn-cookies copy the running configuration to the start-upconfiguration file, and reset the device. Gxxx-001(config)# copy running-config startup-config Gxxx-001(config)# reset ... ! Coming up from reset - syn-cookies are now enabled
To disable SYN cookies:
Gxxx-001(config)# no tcp syn-cookies To disable tcp syn-cookies copy the running configuration to the start-upconfiguration file, and reset the device.
